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/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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/* pngrtran.c - transforms the data in a row for PNG readers
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*
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* This file is available under and governed by the GNU General Public
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* License version 2 only, as published by the Free Software Foundation.
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* However, the following notice accompanied the original version of this
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* file and, per its terms, should not be removed:
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*
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35296
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* Last changed in libpng 1.6.19 [November 12, 2015]
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* Copyright (c) 1998-2015 Glenn Randers-Pehrson
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* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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*
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* This code is released under the libpng license.
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* For conditions of distribution and use, see the disclaimer
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* and license in png.h
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*
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* This file contains functions optionally called by an application
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* in order to tell libpng how to handle data when reading a PNG.
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* Transformations that are used in both reading and writing are
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* in pngtrans.c.
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*/
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#include "pngpriv.h"
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#ifdef PNG_READ_SUPPORTED
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2
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/* Set the action on getting a CRC error for an ancillary or critical chunk. */
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void PNGAPI
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29913
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png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action)
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{
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png_debug(1, "in png_set_crc_action");
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if (png_ptr == NULL)
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return;
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/* Tell libpng how we react to CRC errors in critical chunks */
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switch (crit_action)
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{
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10576
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case PNG_CRC_NO_CHANGE: /* Leave setting as is */
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break;
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case PNG_CRC_WARN_USE: /* Warn/use data */
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png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
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png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
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break;
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case PNG_CRC_QUIET_USE: /* Quiet/use data */
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png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
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png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
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PNG_FLAG_CRC_CRITICAL_IGNORE;
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break;
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case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */
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png_warning(png_ptr,
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"Can't discard critical data on CRC error");
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case PNG_CRC_ERROR_QUIT: /* Error/quit */
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case PNG_CRC_DEFAULT:
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default:
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png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
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break;
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}
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/* Tell libpng how we react to CRC errors in ancillary chunks */
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switch (ancil_action)
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{
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case PNG_CRC_NO_CHANGE: /* Leave setting as is */
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break;
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case PNG_CRC_WARN_USE: /* Warn/use data */
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png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
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png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
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break;
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case PNG_CRC_QUIET_USE: /* Quiet/use data */
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png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
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png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
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PNG_FLAG_CRC_ANCILLARY_NOWARN;
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break;
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case PNG_CRC_ERROR_QUIT: /* Error/quit */
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png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
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png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
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break;
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case PNG_CRC_WARN_DISCARD: /* Warn/discard data */
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case PNG_CRC_DEFAULT:
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default:
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png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
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break;
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}
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}
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29913
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#ifdef PNG_READ_TRANSFORMS_SUPPORTED
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/* Is it OK to set a transformation now? Only if png_start_read_image or
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* png_read_update_info have not been called. It is not necessary for the IHDR
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* to have been read in all cases; the need_IHDR parameter allows for this
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* check too.
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*/
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static int
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png_rtran_ok(png_structrp png_ptr, int need_IHDR)
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{
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if (png_ptr != NULL)
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{
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if ((png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
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png_app_error(png_ptr,
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"invalid after png_start_read_image or png_read_update_info");
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else if (need_IHDR && (png_ptr->mode & PNG_HAVE_IHDR) == 0)
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png_app_error(png_ptr, "invalid before the PNG header has been read");
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else
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{
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/* Turn on failure to initialize correctly for all transforms. */
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png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
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return 1; /* Ok */
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}
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}
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return 0; /* no png_error possible! */
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}
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#endif
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#ifdef PNG_READ_BACKGROUND_SUPPORTED
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/* Handle alpha and tRNS via a background color */
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void PNGFAPI
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png_set_background_fixed(png_structrp png_ptr,
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png_const_color_16p background_color, int background_gamma_code,
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int need_expand, png_fixed_point background_gamma)
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{
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png_debug(1, "in png_set_background_fixed");
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29913
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if (png_rtran_ok(png_ptr, 0) == 0 || background_color == NULL)
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return;
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2
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if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
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{
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png_warning(png_ptr, "Application must supply a known background gamma");
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return;
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}
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png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA;
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png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
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png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
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29913
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png_ptr->background = *background_color;
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png_ptr->background_gamma = background_gamma;
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2
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png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
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29913
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if (need_expand != 0)
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png_ptr->transformations |= PNG_BACKGROUND_EXPAND;
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else
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png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
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}
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# ifdef PNG_FLOATING_POINT_SUPPORTED
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void PNGAPI
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29913
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png_set_background(png_structrp png_ptr,
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10576
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png_const_color_16p background_color, int background_gamma_code,
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int need_expand, double background_gamma)
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{
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png_set_background_fixed(png_ptr, background_color, background_gamma_code,
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need_expand, png_fixed(png_ptr, background_gamma, "png_set_background"));
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}
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# endif /* FLOATING_POINT */
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#endif /* READ_BACKGROUND */
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192 |
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193 |
/* Scale 16-bit depth files to 8-bit depth. If both of these are set then the
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* one that pngrtran does first (scale) happens. This is necessary to allow the
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* TRANSFORM and API behavior to be somewhat consistent, and it's simpler.
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*/
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#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
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void PNGAPI
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29913
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png_set_scale_16(png_structrp png_ptr)
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10576
|
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{
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png_debug(1, "in png_set_scale_16");
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202 |
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29913
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203 |
if (png_rtran_ok(png_ptr, 0) == 0)
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10576
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204 |
return;
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205 |
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206 |
png_ptr->transformations |= PNG_SCALE_16_TO_8;
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2
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}
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208 |
#endif
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209 |
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10576
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210 |
#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
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211 |
/* Chop 16-bit depth files to 8-bit depth */
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2
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void PNGAPI
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29913
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png_set_strip_16(png_structrp png_ptr)
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2
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{
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10576
|
215 |
png_debug(1, "in png_set_strip_16");
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216 |
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29913
|
217 |
if (png_rtran_ok(png_ptr, 0) == 0)
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10576
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218 |
return;
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219 |
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2
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png_ptr->transformations |= PNG_16_TO_8;
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221 |
}
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222 |
#endif
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223 |
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10576
|
224 |
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
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2
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225 |
void PNGAPI
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29913
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226 |
png_set_strip_alpha(png_structrp png_ptr)
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2
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227 |
{
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10576
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png_debug(1, "in png_set_strip_alpha");
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229 |
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29913
|
230 |
if (png_rtran_ok(png_ptr, 0) == 0)
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10576
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231 |
return;
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232 |
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233 |
png_ptr->transformations |= PNG_STRIP_ALPHA;
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2
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234 |
}
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235 |
#endif
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236 |
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10576
|
237 |
#if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED)
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|
238 |
static png_fixed_point
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29913
|
239 |
translate_gamma_flags(png_structrp png_ptr, png_fixed_point output_gamma,
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10576
|
240 |
int is_screen)
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|
241 |
{
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|
242 |
/* Check for flag values. The main reason for having the old Mac value as a
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|
243 |
* flag is that it is pretty near impossible to work out what the correct
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|
244 |
* value is from Apple documentation - a working Mac system is needed to
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245 |
* discover the value!
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246 |
*/
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247 |
if (output_gamma == PNG_DEFAULT_sRGB ||
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248 |
output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB)
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|
249 |
{
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|
250 |
/* If there is no sRGB support this just sets the gamma to the standard
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|
251 |
* sRGB value. (This is a side effect of using this function!)
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252 |
*/
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253 |
# ifdef PNG_READ_sRGB_SUPPORTED
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254 |
png_ptr->flags |= PNG_FLAG_ASSUME_sRGB;
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29913
|
255 |
# else
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|
256 |
PNG_UNUSED(png_ptr)
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10576
|
257 |
# endif
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29913
|
258 |
if (is_screen != 0)
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10576
|
259 |
output_gamma = PNG_GAMMA_sRGB;
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|
260 |
else
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|
261 |
output_gamma = PNG_GAMMA_sRGB_INVERSE;
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|
262 |
}
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|
263 |
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|
264 |
else if (output_gamma == PNG_GAMMA_MAC_18 ||
|
|
|
265 |
output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18)
|
|
|
266 |
{
|
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29913
|
267 |
if (is_screen != 0)
|
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10576
|
268 |
output_gamma = PNG_GAMMA_MAC_OLD;
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|
269 |
else
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|
270 |
output_gamma = PNG_GAMMA_MAC_INVERSE;
|
|
|
271 |
}
|
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|
272 |
|
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|
273 |
return output_gamma;
|
|
|
274 |
}
|
|
|
275 |
|
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|
276 |
# ifdef PNG_FLOATING_POINT_SUPPORTED
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|
|
277 |
static png_fixed_point
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29913
|
278 |
convert_gamma_value(png_structrp png_ptr, double output_gamma)
|
|
10576
|
279 |
{
|
|
|
280 |
/* The following silently ignores cases where fixed point (times 100,000)
|
|
|
281 |
* gamma values are passed to the floating point API. This is safe and it
|
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|
282 |
* means the fixed point constants work just fine with the floating point
|
|
|
283 |
* API. The alternative would just lead to undetected errors and spurious
|
|
|
284 |
* bug reports. Negative values fail inside the _fixed API unless they
|
|
|
285 |
* correspond to the flag values.
|
|
|
286 |
*/
|
|
|
287 |
if (output_gamma > 0 && output_gamma < 128)
|
|
|
288 |
output_gamma *= PNG_FP_1;
|
|
|
289 |
|
|
|
290 |
/* This preserves -1 and -2 exactly: */
|
|
|
291 |
output_gamma = floor(output_gamma + .5);
|
|
|
292 |
|
|
|
293 |
if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN)
|
|
|
294 |
png_fixed_error(png_ptr, "gamma value");
|
|
|
295 |
|
|
|
296 |
return (png_fixed_point)output_gamma;
|
|
|
297 |
}
|
|
|
298 |
# endif
|
|
|
299 |
#endif /* READ_ALPHA_MODE || READ_GAMMA */
|
|
|
300 |
|
|
|
301 |
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
|
|
|
302 |
void PNGFAPI
|
|
29913
|
303 |
png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
|
|
10576
|
304 |
png_fixed_point output_gamma)
|
|
|
305 |
{
|
|
|
306 |
int compose = 0;
|
|
|
307 |
png_fixed_point file_gamma;
|
|
|
308 |
|
|
|
309 |
png_debug(1, "in png_set_alpha_mode");
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|
|
310 |
|
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29913
|
311 |
if (png_rtran_ok(png_ptr, 0) == 0)
|
|
10576
|
312 |
return;
|
|
|
313 |
|
|
|
314 |
output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/);
|
|
|
315 |
|
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|
316 |
/* Validate the value to ensure it is in a reasonable range. The value
|
|
|
317 |
* is expected to be 1 or greater, but this range test allows for some
|
|
|
318 |
* viewing correction values. The intent is to weed out users of this API
|
|
|
319 |
* who use the inverse of the gamma value accidentally! Since some of these
|
|
|
320 |
* values are reasonable this may have to be changed.
|
|
|
321 |
*/
|
|
|
322 |
if (output_gamma < 70000 || output_gamma > 300000)
|
|
|
323 |
png_error(png_ptr, "output gamma out of expected range");
|
|
|
324 |
|
|
|
325 |
/* The default file gamma is the inverse of the output gamma; the output
|
|
|
326 |
* gamma may be changed below so get the file value first:
|
|
|
327 |
*/
|
|
|
328 |
file_gamma = png_reciprocal(output_gamma);
|
|
|
329 |
|
|
|
330 |
/* There are really 8 possibilities here, composed of any combination
|
|
|
331 |
* of:
|
|
|
332 |
*
|
|
|
333 |
* premultiply the color channels
|
|
|
334 |
* do not encode non-opaque pixels
|
|
|
335 |
* encode the alpha as well as the color channels
|
|
|
336 |
*
|
|
|
337 |
* The differences disappear if the input/output ('screen') gamma is 1.0,
|
|
|
338 |
* because then the encoding is a no-op and there is only the choice of
|
|
|
339 |
* premultiplying the color channels or not.
|
|
|
340 |
*
|
|
|
341 |
* png_set_alpha_mode and png_set_background interact because both use
|
|
|
342 |
* png_compose to do the work. Calling both is only useful when
|
|
|
343 |
* png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along
|
|
|
344 |
* with a default gamma value. Otherwise PNG_COMPOSE must not be set.
|
|
|
345 |
*/
|
|
|
346 |
switch (mode)
|
|
|
347 |
{
|
|
|
348 |
case PNG_ALPHA_PNG: /* default: png standard */
|
|
|
349 |
/* No compose, but it may be set by png_set_background! */
|
|
|
350 |
png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
|
|
351 |
png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
|
|
352 |
break;
|
|
|
353 |
|
|
|
354 |
case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */
|
|
|
355 |
compose = 1;
|
|
|
356 |
png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
|
|
357 |
png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
|
|
358 |
/* The output is linear: */
|
|
|
359 |
output_gamma = PNG_FP_1;
|
|
|
360 |
break;
|
|
|
361 |
|
|
|
362 |
case PNG_ALPHA_OPTIMIZED: /* associated, non-opaque pixels linear */
|
|
|
363 |
compose = 1;
|
|
|
364 |
png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
|
|
365 |
png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA;
|
|
|
366 |
/* output_gamma records the encoding of opaque pixels! */
|
|
|
367 |
break;
|
|
|
368 |
|
|
|
369 |
case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */
|
|
|
370 |
compose = 1;
|
|
|
371 |
png_ptr->transformations |= PNG_ENCODE_ALPHA;
|
|
|
372 |
png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
|
|
373 |
break;
|
|
|
374 |
|
|
|
375 |
default:
|
|
|
376 |
png_error(png_ptr, "invalid alpha mode");
|
|
|
377 |
}
|
|
|
378 |
|
|
|
379 |
/* Only set the default gamma if the file gamma has not been set (this has
|
|
|
380 |
* the side effect that the gamma in a second call to png_set_alpha_mode will
|
|
|
381 |
* be ignored.)
|
|
|
382 |
*/
|
|
29913
|
383 |
if (png_ptr->colorspace.gamma == 0)
|
|
|
384 |
{
|
|
|
385 |
png_ptr->colorspace.gamma = file_gamma;
|
|
|
386 |
png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
|
|
|
387 |
}
|
|
10576
|
388 |
|
|
|
389 |
/* But always set the output gamma: */
|
|
|
390 |
png_ptr->screen_gamma = output_gamma;
|
|
|
391 |
|
|
|
392 |
/* Finally, if pre-multiplying, set the background fields to achieve the
|
|
|
393 |
* desired result.
|
|
|
394 |
*/
|
|
29913
|
395 |
if (compose != 0)
|
|
10576
|
396 |
{
|
|
|
397 |
/* And obtain alpha pre-multiplication by composing on black: */
|
|
29913
|
398 |
memset(&png_ptr->background, 0, (sizeof png_ptr->background));
|
|
|
399 |
png_ptr->background_gamma = png_ptr->colorspace.gamma; /* just in case */
|
|
10576
|
400 |
png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE;
|
|
|
401 |
png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
|
|
|
402 |
|
|
29913
|
403 |
if ((png_ptr->transformations & PNG_COMPOSE) != 0)
|
|
10576
|
404 |
png_error(png_ptr,
|
|
|
405 |
"conflicting calls to set alpha mode and background");
|
|
|
406 |
|
|
|
407 |
png_ptr->transformations |= PNG_COMPOSE;
|
|
|
408 |
}
|
|
|
409 |
}
|
|
|
410 |
|
|
|
411 |
# ifdef PNG_FLOATING_POINT_SUPPORTED
|
|
|
412 |
void PNGAPI
|
|
29913
|
413 |
png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma)
|
|
10576
|
414 |
{
|
|
|
415 |
png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr,
|
|
|
416 |
output_gamma));
|
|
|
417 |
}
|
|
|
418 |
# endif
|
|
|
419 |
#endif
|
|
|
420 |
|
|
|
421 |
#ifdef PNG_READ_QUANTIZE_SUPPORTED
|
|
|
422 |
/* Dither file to 8-bit. Supply a palette, the current number
|
|
2
|
423 |
* of elements in the palette, the maximum number of elements
|
|
|
424 |
* allowed, and a histogram if possible. If the current number
|
|
35296
|
425 |
* of colors is greater than the maximum number, the palette will be
|
|
10576
|
426 |
* modified to fit in the maximum number. "full_quantize" indicates
|
|
|
427 |
* whether we need a quantizing cube set up for RGB images, or if we
|
|
2
|
428 |
* simply are reducing the number of colors in a paletted image.
|
|
|
429 |
*/
|
|
|
430 |
|
|
|
431 |
typedef struct png_dsort_struct
|
|
|
432 |
{
|
|
29913
|
433 |
struct png_dsort_struct * next;
|
|
2
|
434 |
png_byte left;
|
|
|
435 |
png_byte right;
|
|
|
436 |
} png_dsort;
|
|
29913
|
437 |
typedef png_dsort * png_dsortp;
|
|
|
438 |
typedef png_dsort * * png_dsortpp;
|
|
2
|
439 |
|
|
|
440 |
void PNGAPI
|
|
29913
|
441 |
png_set_quantize(png_structrp png_ptr, png_colorp palette,
|
|
10576
|
442 |
int num_palette, int maximum_colors, png_const_uint_16p histogram,
|
|
|
443 |
int full_quantize)
|
|
2
|
444 |
{
|
|
10576
|
445 |
png_debug(1, "in png_set_quantize");
|
|
|
446 |
|
|
29913
|
447 |
if (png_rtran_ok(png_ptr, 0) == 0)
|
|
10576
|
448 |
return;
|
|
|
449 |
|
|
|
450 |
png_ptr->transformations |= PNG_QUANTIZE;
|
|
|
451 |
|
|
29913
|
452 |
if (full_quantize == 0)
|
|
2
|
453 |
{
|
|
|
454 |
int i;
|
|
|
455 |
|
|
10576
|
456 |
png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
|
|
29913
|
457 |
(png_uint_32)(num_palette * (sizeof (png_byte))));
|
|
2
|
458 |
for (i = 0; i < num_palette; i++)
|
|
10576
|
459 |
png_ptr->quantize_index[i] = (png_byte)i;
|
|
2
|
460 |
}
|
|
|
461 |
|
|
|
462 |
if (num_palette > maximum_colors)
|
|
|
463 |
{
|
|
|
464 |
if (histogram != NULL)
|
|
|
465 |
{
|
|
|
466 |
/* This is easy enough, just throw out the least used colors.
|
|
10576
|
467 |
* Perhaps not the best solution, but good enough.
|
|
|
468 |
*/
|
|
2
|
469 |
|
|
|
470 |
int i;
|
|
|
471 |
|
|
10576
|
472 |
/* Initialize an array to sort colors */
|
|
|
473 |
png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
|
|
29913
|
474 |
(png_uint_32)(num_palette * (sizeof (png_byte))));
|
|
10576
|
475 |
|
|
|
476 |
/* Initialize the quantize_sort array */
|
|
2
|
477 |
for (i = 0; i < num_palette; i++)
|
|
10576
|
478 |
png_ptr->quantize_sort[i] = (png_byte)i;
|
|
2
|
479 |
|
|
|
480 |
/* Find the least used palette entries by starting a
|
|
10576
|
481 |
* bubble sort, and running it until we have sorted
|
|
|
482 |
* out enough colors. Note that we don't care about
|
|
|
483 |
* sorting all the colors, just finding which are
|
|
|
484 |
* least used.
|
|
|
485 |
*/
|
|
2
|
486 |
|
|
|
487 |
for (i = num_palette - 1; i >= maximum_colors; i--)
|
|
|
488 |
{
|
|
10576
|
489 |
int done; /* To stop early if the list is pre-sorted */
|
|
2
|
490 |
int j;
|
|
|
491 |
|
|
|
492 |
done = 1;
|
|
|
493 |
for (j = 0; j < i; j++)
|
|
|
494 |
{
|
|
10576
|
495 |
if (histogram[png_ptr->quantize_sort[j]]
|
|
|
496 |
< histogram[png_ptr->quantize_sort[j + 1]])
|
|
2
|
497 |
{
|
|
|
498 |
png_byte t;
|
|
|
499 |
|
|
10576
|
500 |
t = png_ptr->quantize_sort[j];
|
|
|
501 |
png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1];
|
|
|
502 |
png_ptr->quantize_sort[j + 1] = t;
|
|
2
|
503 |
done = 0;
|
|
|
504 |
}
|
|
|
505 |
}
|
|
10576
|
506 |
|
|
29913
|
507 |
if (done != 0)
|
|
2
|
508 |
break;
|
|
|
509 |
}
|
|
|
510 |
|
|
10576
|
511 |
/* Swap the palette around, and set up a table, if necessary */
|
|
29913
|
512 |
if (full_quantize != 0)
|
|
2
|
513 |
{
|
|
|
514 |
int j = num_palette;
|
|
|
515 |
|
|
10576
|
516 |
/* Put all the useful colors within the max, but don't
|
|
|
517 |
* move the others.
|
|
|
518 |
*/
|
|
2
|
519 |
for (i = 0; i < maximum_colors; i++)
|
|
|
520 |
{
|
|
10576
|
521 |
if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
|
|
2
|
522 |
{
|
|
|
523 |
do
|
|
|
524 |
j--;
|
|
10576
|
525 |
while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
|
|
|
526 |
|
|
2
|
527 |
palette[i] = palette[j];
|
|
|
528 |
}
|
|
|
529 |
}
|
|
|
530 |
}
|
|
|
531 |
else
|
|
|
532 |
{
|
|
|
533 |
int j = num_palette;
|
|
|
534 |
|
|
10576
|
535 |
/* Move all the used colors inside the max limit, and
|
|
|
536 |
* develop a translation table.
|
|
|
537 |
*/
|
|
2
|
538 |
for (i = 0; i < maximum_colors; i++)
|
|
|
539 |
{
|
|
10576
|
540 |
/* Only move the colors we need to */
|
|
|
541 |
if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
|
|
2
|
542 |
{
|
|
|
543 |
png_color tmp_color;
|
|
|
544 |
|
|
|
545 |
do
|
|
|
546 |
j--;
|
|
10576
|
547 |
while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
|
|
2
|
548 |
|
|
|
549 |
tmp_color = palette[j];
|
|
|
550 |
palette[j] = palette[i];
|
|
|
551 |
palette[i] = tmp_color;
|
|
10576
|
552 |
/* Indicate where the color went */
|
|
|
553 |
png_ptr->quantize_index[j] = (png_byte)i;
|
|
|
554 |
png_ptr->quantize_index[i] = (png_byte)j;
|
|
2
|
555 |
}
|
|
|
556 |
}
|
|
|
557 |
|
|
10576
|
558 |
/* Find closest color for those colors we are not using */
|
|
2
|
559 |
for (i = 0; i < num_palette; i++)
|
|
|
560 |
{
|
|
10576
|
561 |
if ((int)png_ptr->quantize_index[i] >= maximum_colors)
|
|
2
|
562 |
{
|
|
|
563 |
int min_d, k, min_k, d_index;
|
|
|
564 |
|
|
10576
|
565 |
/* Find the closest color to one we threw out */
|
|
|
566 |
d_index = png_ptr->quantize_index[i];
|
|
2
|
567 |
min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
|
|
|
568 |
for (k = 1, min_k = 0; k < maximum_colors; k++)
|
|
|
569 |
{
|
|
|
570 |
int d;
|
|
|
571 |
|
|
|
572 |
d = PNG_COLOR_DIST(palette[d_index], palette[k]);
|
|
|
573 |
|
|
|
574 |
if (d < min_d)
|
|
|
575 |
{
|
|
|
576 |
min_d = d;
|
|
|
577 |
min_k = k;
|
|
|
578 |
}
|
|
|
579 |
}
|
|
10576
|
580 |
/* Point to closest color */
|
|
|
581 |
png_ptr->quantize_index[i] = (png_byte)min_k;
|
|
2
|
582 |
}
|
|
|
583 |
}
|
|
|
584 |
}
|
|
10576
|
585 |
png_free(png_ptr, png_ptr->quantize_sort);
|
|
|
586 |
png_ptr->quantize_sort = NULL;
|
|
2
|
587 |
}
|
|
|
588 |
else
|
|
|
589 |
{
|
|
|
590 |
/* This is much harder to do simply (and quickly). Perhaps
|
|
10576
|
591 |
* we need to go through a median cut routine, but those
|
|
|
592 |
* don't always behave themselves with only a few colors
|
|
|
593 |
* as input. So we will just find the closest two colors,
|
|
|
594 |
* and throw out one of them (chosen somewhat randomly).
|
|
|
595 |
* [We don't understand this at all, so if someone wants to
|
|
|
596 |
* work on improving it, be our guest - AED, GRP]
|
|
|
597 |
*/
|
|
2
|
598 |
int i;
|
|
|
599 |
int max_d;
|
|
|
600 |
int num_new_palette;
|
|
|
601 |
png_dsortp t;
|
|
|
602 |
png_dsortpp hash;
|
|
|
603 |
|
|
10576
|
604 |
t = NULL;
|
|
|
605 |
|
|
|
606 |
/* Initialize palette index arrays */
|
|
2
|
607 |
png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
|
|
29913
|
608 |
(png_uint_32)(num_palette * (sizeof (png_byte))));
|
|
2
|
609 |
png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
|
|
29913
|
610 |
(png_uint_32)(num_palette * (sizeof (png_byte))));
|
|
10576
|
611 |
|
|
|
612 |
/* Initialize the sort array */
|
|
2
|
613 |
for (i = 0; i < num_palette; i++)
|
|
|
614 |
{
|
|
|
615 |
png_ptr->index_to_palette[i] = (png_byte)i;
|
|
|
616 |
png_ptr->palette_to_index[i] = (png_byte)i;
|
|
|
617 |
}
|
|
|
618 |
|
|
10576
|
619 |
hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 *
|
|
29913
|
620 |
(sizeof (png_dsortp))));
|
|
2
|
621 |
|
|
|
622 |
num_new_palette = num_palette;
|
|
|
623 |
|
|
10576
|
624 |
/* Initial wild guess at how far apart the farthest pixel
|
|
|
625 |
* pair we will be eliminating will be. Larger
|
|
|
626 |
* numbers mean more areas will be allocated, Smaller
|
|
|
627 |
* numbers run the risk of not saving enough data, and
|
|
|
628 |
* having to do this all over again.
|
|
|
629 |
*
|
|
|
630 |
* I have not done extensive checking on this number.
|
|
|
631 |
*/
|
|
2
|
632 |
max_d = 96;
|
|
|
633 |
|
|
|
634 |
while (num_new_palette > maximum_colors)
|
|
|
635 |
{
|
|
|
636 |
for (i = 0; i < num_new_palette - 1; i++)
|
|
|
637 |
{
|
|
|
638 |
int j;
|
|
|
639 |
|
|
|
640 |
for (j = i + 1; j < num_new_palette; j++)
|
|
|
641 |
{
|
|
|
642 |
int d;
|
|
|
643 |
|
|
|
644 |
d = PNG_COLOR_DIST(palette[i], palette[j]);
|
|
|
645 |
|
|
|
646 |
if (d <= max_d)
|
|
|
647 |
{
|
|
|
648 |
|
|
|
649 |
t = (png_dsortp)png_malloc_warn(png_ptr,
|
|
29913
|
650 |
(png_uint_32)(sizeof (png_dsort)));
|
|
10576
|
651 |
|
|
2
|
652 |
if (t == NULL)
|
|
|
653 |
break;
|
|
10576
|
654 |
|
|
2
|
655 |
t->next = hash[d];
|
|
|
656 |
t->left = (png_byte)i;
|
|
|
657 |
t->right = (png_byte)j;
|
|
|
658 |
hash[d] = t;
|
|
|
659 |
}
|
|
|
660 |
}
|
|
|
661 |
if (t == NULL)
|
|
|
662 |
break;
|
|
|
663 |
}
|
|
|
664 |
|
|
|
665 |
if (t != NULL)
|
|
|
666 |
for (i = 0; i <= max_d; i++)
|
|
|
667 |
{
|
|
|
668 |
if (hash[i] != NULL)
|
|
|
669 |
{
|
|
|
670 |
png_dsortp p;
|
|
|
671 |
|
|
|
672 |
for (p = hash[i]; p; p = p->next)
|
|
|
673 |
{
|
|
|
674 |
if ((int)png_ptr->index_to_palette[p->left]
|
|
10576
|
675 |
< num_new_palette &&
|
|
|
676 |
(int)png_ptr->index_to_palette[p->right]
|
|
|
677 |
< num_new_palette)
|
|
2
|
678 |
{
|
|
|
679 |
int j, next_j;
|
|
|
680 |
|
|
|
681 |
if (num_new_palette & 0x01)
|
|
|
682 |
{
|
|
|
683 |
j = p->left;
|
|
|
684 |
next_j = p->right;
|
|
|
685 |
}
|
|
|
686 |
else
|
|
|
687 |
{
|
|
|
688 |
j = p->right;
|
|
|
689 |
next_j = p->left;
|
|
|
690 |
}
|
|
|
691 |
|
|
|
692 |
num_new_palette--;
|
|
|
693 |
palette[png_ptr->index_to_palette[j]]
|
|
10576
|
694 |
= palette[num_new_palette];
|
|
29913
|
695 |
if (full_quantize == 0)
|
|
2
|
696 |
{
|
|
|
697 |
int k;
|
|
|
698 |
|
|
|
699 |
for (k = 0; k < num_palette; k++)
|
|
|
700 |
{
|
|
10576
|
701 |
if (png_ptr->quantize_index[k] ==
|
|
|
702 |
png_ptr->index_to_palette[j])
|
|
|
703 |
png_ptr->quantize_index[k] =
|
|
|
704 |
png_ptr->index_to_palette[next_j];
|
|
|
705 |
|
|
|
706 |
if ((int)png_ptr->quantize_index[k] ==
|
|
|
707 |
num_new_palette)
|
|
|
708 |
png_ptr->quantize_index[k] =
|
|
|
709 |
png_ptr->index_to_palette[j];
|
|
2
|
710 |
}
|
|
|
711 |
}
|
|
|
712 |
|
|
|
713 |
png_ptr->index_to_palette[png_ptr->palette_to_index
|
|
10576
|
714 |
[num_new_palette]] = png_ptr->index_to_palette[j];
|
|
|
715 |
|
|
2
|
716 |
png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
|
|
10576
|
717 |
= png_ptr->palette_to_index[num_new_palette];
|
|
|
718 |
|
|
|
719 |
png_ptr->index_to_palette[j] =
|
|
|
720 |
(png_byte)num_new_palette;
|
|
|
721 |
|
|
|
722 |
png_ptr->palette_to_index[num_new_palette] =
|
|
|
723 |
(png_byte)j;
|
|
2
|
724 |
}
|
|
|
725 |
if (num_new_palette <= maximum_colors)
|
|
|
726 |
break;
|
|
|
727 |
}
|
|
|
728 |
if (num_new_palette <= maximum_colors)
|
|
|
729 |
break;
|
|
|
730 |
}
|
|
|
731 |
}
|
|
|
732 |
|
|
|
733 |
for (i = 0; i < 769; i++)
|
|
|
734 |
{
|
|
|
735 |
if (hash[i] != NULL)
|
|
|
736 |
{
|
|
|
737 |
png_dsortp p = hash[i];
|
|
|
738 |
while (p)
|
|
|
739 |
{
|
|
|
740 |
t = p->next;
|
|
|
741 |
png_free(png_ptr, p);
|
|
|
742 |
p = t;
|
|
|
743 |
}
|
|
|
744 |
}
|
|
|
745 |
hash[i] = 0;
|
|
|
746 |
}
|
|
|
747 |
max_d += 96;
|
|
|
748 |
}
|
|
|
749 |
png_free(png_ptr, hash);
|
|
|
750 |
png_free(png_ptr, png_ptr->palette_to_index);
|
|
|
751 |
png_free(png_ptr, png_ptr->index_to_palette);
|
|
10576
|
752 |
png_ptr->palette_to_index = NULL;
|
|
|
753 |
png_ptr->index_to_palette = NULL;
|
|
2
|
754 |
}
|
|
|
755 |
num_palette = maximum_colors;
|
|
|
756 |
}
|
|
|
757 |
if (png_ptr->palette == NULL)
|
|
|
758 |
{
|
|
|
759 |
png_ptr->palette = palette;
|
|
|
760 |
}
|
|
|
761 |
png_ptr->num_palette = (png_uint_16)num_palette;
|
|
|
762 |
|
|
29913
|
763 |
if (full_quantize != 0)
|
|
2
|
764 |
{
|
|
|
765 |
int i;
|
|
|
766 |
png_bytep distance;
|
|
10576
|
767 |
int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS +
|
|
|
768 |
PNG_QUANTIZE_BLUE_BITS;
|
|
|
769 |
int num_red = (1 << PNG_QUANTIZE_RED_BITS);
|
|
|
770 |
int num_green = (1 << PNG_QUANTIZE_GREEN_BITS);
|
|
|
771 |
int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS);
|
|
2
|
772 |
png_size_t num_entries = ((png_size_t)1 << total_bits);
|
|
|
773 |
|
|
10576
|
774 |
png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr,
|
|
29913
|
775 |
(png_uint_32)(num_entries * (sizeof (png_byte))));
|
|
2
|
776 |
|
|
|
777 |
distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
|
|
29913
|
778 |
(sizeof (png_byte))));
|
|
|
779 |
|
|
|
780 |
memset(distance, 0xff, num_entries * (sizeof (png_byte)));
|
|
2
|
781 |
|
|
|
782 |
for (i = 0; i < num_palette; i++)
|
|
|
783 |
{
|
|
|
784 |
int ir, ig, ib;
|
|
10576
|
785 |
int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS));
|
|
|
786 |
int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS));
|
|
|
787 |
int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS));
|
|
2
|
788 |
|
|
|
789 |
for (ir = 0; ir < num_red; ir++)
|
|
|
790 |
{
|
|
|
791 |
/* int dr = abs(ir - r); */
|
|
|
792 |
int dr = ((ir > r) ? ir - r : r - ir);
|
|
10576
|
793 |
int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS +
|
|
|
794 |
PNG_QUANTIZE_GREEN_BITS));
|
|
2
|
795 |
|
|
|
796 |
for (ig = 0; ig < num_green; ig++)
|
|
|
797 |
{
|
|
|
798 |
/* int dg = abs(ig - g); */
|
|
|
799 |
int dg = ((ig > g) ? ig - g : g - ig);
|
|
|
800 |
int dt = dr + dg;
|
|
|
801 |
int dm = ((dr > dg) ? dr : dg);
|
|
10576
|
802 |
int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS);
|
|
2
|
803 |
|
|
|
804 |
for (ib = 0; ib < num_blue; ib++)
|
|
|
805 |
{
|
|
|
806 |
int d_index = index_g | ib;
|
|
|
807 |
/* int db = abs(ib - b); */
|
|
|
808 |
int db = ((ib > b) ? ib - b : b - ib);
|
|
|
809 |
int dmax = ((dm > db) ? dm : db);
|
|
|
810 |
int d = dmax + dt + db;
|
|
|
811 |
|
|
|
812 |
if (d < (int)distance[d_index])
|
|
|
813 |
{
|
|
|
814 |
distance[d_index] = (png_byte)d;
|
|
|
815 |
png_ptr->palette_lookup[d_index] = (png_byte)i;
|
|
|
816 |
}
|
|
|
817 |
}
|
|
|
818 |
}
|
|
|
819 |
}
|
|
|
820 |
}
|
|
|
821 |
|
|
|
822 |
png_free(png_ptr, distance);
|
|
|
823 |
}
|
|
|
824 |
}
|
|
29913
|
825 |
#endif /* READ_QUANTIZE */
|
|
10576
|
826 |
|
|
|
827 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
|
828 |
void PNGFAPI
|
|
29913
|
829 |
png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma,
|
|
10576
|
830 |
png_fixed_point file_gamma)
|
|
|
831 |
{
|
|
|
832 |
png_debug(1, "in png_set_gamma_fixed");
|
|
|
833 |
|
|
29913
|
834 |
if (png_rtran_ok(png_ptr, 0) == 0)
|
|
10576
|
835 |
return;
|
|
|
836 |
|
|
|
837 |
/* New in libpng-1.5.4 - reserve particular negative values as flags. */
|
|
|
838 |
scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/);
|
|
|
839 |
file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/);
|
|
|
840 |
|
|
|
841 |
/* Checking the gamma values for being >0 was added in 1.5.4 along with the
|
|
|
842 |
* premultiplied alpha support; this actually hides an undocumented feature
|
|
|
843 |
* of the previous implementation which allowed gamma processing to be
|
|
|
844 |
* disabled in background handling. There is no evidence (so far) that this
|
|
|
845 |
* was being used; however, png_set_background itself accepted and must still
|
|
|
846 |
* accept '0' for the gamma value it takes, because it isn't always used.
|
|
|
847 |
*
|
|
|
848 |
* Since this is an API change (albeit a very minor one that removes an
|
|
29913
|
849 |
* undocumented API feature) the following checks were only enabled in
|
|
|
850 |
* libpng-1.6.0.
|
|
10576
|
851 |
*/
|
|
|
852 |
if (file_gamma <= 0)
|
|
|
853 |
png_error(png_ptr, "invalid file gamma in png_set_gamma");
|
|
|
854 |
|
|
|
855 |
if (scrn_gamma <= 0)
|
|
|
856 |
png_error(png_ptr, "invalid screen gamma in png_set_gamma");
|
|
2
|
857 |
|
|
10576
|
858 |
/* Set the gamma values unconditionally - this overrides the value in the PNG
|
|
|
859 |
* file if a gAMA chunk was present. png_set_alpha_mode provides a
|
|
|
860 |
* different, easier, way to default the file gamma.
|
|
|
861 |
*/
|
|
29913
|
862 |
png_ptr->colorspace.gamma = file_gamma;
|
|
|
863 |
png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
|
|
10576
|
864 |
png_ptr->screen_gamma = scrn_gamma;
|
|
|
865 |
}
|
|
|
866 |
|
|
|
867 |
# ifdef PNG_FLOATING_POINT_SUPPORTED
|
|
2
|
868 |
void PNGAPI
|
|
29913
|
869 |
png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma)
|
|
2
|
870 |
{
|
|
10576
|
871 |
png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma),
|
|
|
872 |
convert_gamma_value(png_ptr, file_gamma));
|
|
2
|
873 |
}
|
|
29913
|
874 |
# endif /* FLOATING_POINT */
|
|
10576
|
875 |
#endif /* READ_GAMMA */
|
|
|
876 |
|
|
|
877 |
#ifdef PNG_READ_EXPAND_SUPPORTED
|
|
2
|
878 |
/* Expand paletted images to RGB, expand grayscale images of
|
|
|
879 |
* less than 8-bit depth to 8-bit depth, and expand tRNS chunks
|
|
|
880 |
* to alpha channels.
|
|
|
881 |
*/
|
|
|
882 |
void PNGAPI
|
|
29913
|
883 |
png_set_expand(png_structrp png_ptr)
|
|
2
|
884 |
{
|
|
10576
|
885 |
png_debug(1, "in png_set_expand");
|
|
|
886 |
|
|
29913
|
887 |
if (png_rtran_ok(png_ptr, 0) == 0)
|
|
10576
|
888 |
return;
|
|
|
889 |
|
|
2
|
890 |
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
|
|
891 |
}
|
|
|
892 |
|
|
|
893 |
/* GRR 19990627: the following three functions currently are identical
|
|
|
894 |
* to png_set_expand(). However, it is entirely reasonable that someone
|
|
|
895 |
* might wish to expand an indexed image to RGB but *not* expand a single,
|
|
|
896 |
* fully transparent palette entry to a full alpha channel--perhaps instead
|
|
|
897 |
* convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
|
|
|
898 |
* the transparent color with a particular RGB value, or drop tRNS entirely.
|
|
|
899 |
* IOW, a future version of the library may make the transformations flag
|
|
|
900 |
* a bit more fine-grained, with separate bits for each of these three
|
|
|
901 |
* functions.
|
|
|
902 |
*
|
|
|
903 |
* More to the point, these functions make it obvious what libpng will be
|
|
|
904 |
* doing, whereas "expand" can (and does) mean any number of things.
|
|
|
905 |
*
|
|
10576
|
906 |
* GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified
|
|
|
907 |
* to expand only the sample depth but not to expand the tRNS to alpha
|
|
|
908 |
* and its name was changed to png_set_expand_gray_1_2_4_to_8().
|
|
2
|
909 |
*/
|
|
|
910 |
|
|
|
911 |
/* Expand paletted images to RGB. */
|
|
|
912 |
void PNGAPI
|
|
29913
|
913 |
png_set_palette_to_rgb(png_structrp png_ptr)
|
|
2
|
914 |
{
|
|
10576
|
915 |
png_debug(1, "in png_set_palette_to_rgb");
|
|
|
916 |
|
|
29913
|
917 |
if (png_rtran_ok(png_ptr, 0) == 0)
|
|
10576
|
918 |
return;
|
|
|
919 |
|
|
2
|
920 |
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
|
|
921 |
}
|
|
|
922 |
|
|
|
923 |
/* Expand grayscale images of less than 8-bit depth to 8 bits. */
|
|
|
924 |
void PNGAPI
|
|
29913
|
925 |
png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr)
|
|
2
|
926 |
{
|
|
10576
|
927 |
png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
|
|
|
928 |
|
|
29913
|
929 |
if (png_rtran_ok(png_ptr, 0) == 0)
|
|
10576
|
930 |
return;
|
|
|
931 |
|
|
2
|
932 |
png_ptr->transformations |= PNG_EXPAND;
|
|
|
933 |
}
|
|
10576
|
934 |
|
|
2
|
935 |
/* Expand tRNS chunks to alpha channels. */
|
|
|
936 |
void PNGAPI
|
|
29913
|
937 |
png_set_tRNS_to_alpha(png_structrp png_ptr)
|
|
2
|
938 |
{
|
|
10576
|
939 |
png_debug(1, "in png_set_tRNS_to_alpha");
|
|
|
940 |
|
|
29913
|
941 |
if (png_rtran_ok(png_ptr, 0) == 0)
|
|
|
942 |
return;
|
|
|
943 |
|
|
2
|
944 |
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
|
|
945 |
}
|
|
29913
|
946 |
#endif /* READ_EXPAND */
|
|
2
|
947 |
|
|
10576
|
948 |
#ifdef PNG_READ_EXPAND_16_SUPPORTED
|
|
|
949 |
/* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise
|
|
|
950 |
* it may not work correctly.)
|
|
|
951 |
*/
|
|
|
952 |
void PNGAPI
|
|
29913
|
953 |
png_set_expand_16(png_structrp png_ptr)
|
|
10576
|
954 |
{
|
|
|
955 |
png_debug(1, "in png_set_expand_16");
|
|
|
956 |
|
|
29913
|
957 |
if (png_rtran_ok(png_ptr, 0) == 0)
|
|
10576
|
958 |
return;
|
|
|
959 |
|
|
|
960 |
png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS);
|
|
|
961 |
}
|
|
|
962 |
#endif
|
|
|
963 |
|
|
|
964 |
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
|
2
|
965 |
void PNGAPI
|
|
29913
|
966 |
png_set_gray_to_rgb(png_structrp png_ptr)
|
|
2
|
967 |
{
|
|
10576
|
968 |
png_debug(1, "in png_set_gray_to_rgb");
|
|
|
969 |
|
|
29913
|
970 |
if (png_rtran_ok(png_ptr, 0) == 0)
|
|
|
971 |
return;
|
|
|
972 |
|
|
|
973 |
/* Because rgb must be 8 bits or more: */
|
|
|
974 |
png_set_expand_gray_1_2_4_to_8(png_ptr);
|
|
|
975 |
png_ptr->transformations |= PNG_GRAY_TO_RGB;
|
|
2
|
976 |
}
|
|
|
977 |
#endif
|
|
|
978 |
|
|
10576
|
979 |
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
|
|
980 |
void PNGFAPI
|
|
29913
|
981 |
png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action,
|
|
10576
|
982 |
png_fixed_point red, png_fixed_point green)
|
|
|
983 |
{
|
|
|
984 |
png_debug(1, "in png_set_rgb_to_gray");
|
|
|
985 |
|
|
29913
|
986 |
/* Need the IHDR here because of the check on color_type below. */
|
|
|
987 |
/* TODO: fix this */
|
|
|
988 |
if (png_rtran_ok(png_ptr, 1) == 0)
|
|
10576
|
989 |
return;
|
|
|
990 |
|
|
29913
|
991 |
switch (error_action)
|
|
10576
|
992 |
{
|
|
29913
|
993 |
case PNG_ERROR_ACTION_NONE:
|
|
10576
|
994 |
png_ptr->transformations |= PNG_RGB_TO_GRAY;
|
|
|
995 |
break;
|
|
|
996 |
|
|
29913
|
997 |
case PNG_ERROR_ACTION_WARN:
|
|
10576
|
998 |
png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
|
|
|
999 |
break;
|
|
|
1000 |
|
|
29913
|
1001 |
case PNG_ERROR_ACTION_ERROR:
|
|
10576
|
1002 |
png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
|
|
|
1003 |
break;
|
|
|
1004 |
|
|
|
1005 |
default:
|
|
|
1006 |
png_error(png_ptr, "invalid error action to rgb_to_gray");
|
|
|
1007 |
}
|
|
29913
|
1008 |
|
|
10576
|
1009 |
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
|
1010 |
#ifdef PNG_READ_EXPAND_SUPPORTED
|
|
|
1011 |
png_ptr->transformations |= PNG_EXPAND;
|
|
|
1012 |
#else
|
|
|
1013 |
{
|
|
29913
|
1014 |
/* Make this an error in 1.6 because otherwise the application may assume
|
|
|
1015 |
* that it just worked and get a memory overwrite.
|
|
|
1016 |
*/
|
|
|
1017 |
png_error(png_ptr,
|
|
10576
|
1018 |
"Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED");
|
|
|
1019 |
|
|
29913
|
1020 |
/* png_ptr->transformations &= ~PNG_RGB_TO_GRAY; */
|
|
10576
|
1021 |
}
|
|
|
1022 |
#endif
|
|
|
1023 |
{
|
|
|
1024 |
if (red >= 0 && green >= 0 && red + green <= PNG_FP_1)
|
|
|
1025 |
{
|
|
|
1026 |
png_uint_16 red_int, green_int;
|
|
|
1027 |
|
|
29913
|
1028 |
/* NOTE: this calculation does not round, but this behavior is retained
|
|
|
1029 |
* for consistency; the inaccuracy is very small. The code here always
|
|
|
1030 |
* overwrites the coefficients, regardless of whether they have been
|
|
|
1031 |
* defaulted or set already.
|
|
|
1032 |
*/
|
|
|
1033 |
red_int = (png_uint_16)(((png_uint_32)red*32768)/100000);
|
|
|
1034 |
green_int = (png_uint_16)(((png_uint_32)green*32768)/100000);
|
|
10576
|
1035 |
|
|
|
1036 |
png_ptr->rgb_to_gray_red_coeff = red_int;
|
|
|
1037 |
png_ptr->rgb_to_gray_green_coeff = green_int;
|
|
29913
|
1038 |
png_ptr->rgb_to_gray_coefficients_set = 1;
|
|
10576
|
1039 |
}
|
|
|
1040 |
|
|
|
1041 |
else
|
|
|
1042 |
{
|
|
|
1043 |
if (red >= 0 && green >= 0)
|
|
29913
|
1044 |
png_app_warning(png_ptr,
|
|
10576
|
1045 |
"ignoring out of range rgb_to_gray coefficients");
|
|
|
1046 |
|
|
29913
|
1047 |
/* Use the defaults, from the cHRM chunk if set, else the historical
|
|
|
1048 |
* values which are close to the sRGB/HDTV/ITU-Rec 709 values. See
|
|
|
1049 |
* png_do_rgb_to_gray for more discussion of the values. In this case
|
|
|
1050 |
* the coefficients are not marked as 'set' and are not overwritten if
|
|
|
1051 |
* something has already provided a default.
|
|
10576
|
1052 |
*/
|
|
|
1053 |
if (png_ptr->rgb_to_gray_red_coeff == 0 &&
|
|
29913
|
1054 |
png_ptr->rgb_to_gray_green_coeff == 0)
|
|
10576
|
1055 |
{
|
|
29913
|
1056 |
png_ptr->rgb_to_gray_red_coeff = 6968;
|
|
|
1057 |
png_ptr->rgb_to_gray_green_coeff = 23434;
|
|
|
1058 |
/* png_ptr->rgb_to_gray_blue_coeff = 2366; */
|
|
10576
|
1059 |
}
|
|
|
1060 |
}
|
|
|
1061 |
}
|
|
|
1062 |
}
|
|
|
1063 |
|
|
|
1064 |
#ifdef PNG_FLOATING_POINT_SUPPORTED
|
|
2
|
1065 |
/* Convert a RGB image to a grayscale of the same width. This allows us,
|
|
|
1066 |
* for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
|
|
|
1067 |
*/
|
|
|
1068 |
|
|
|
1069 |
void PNGAPI
|
|
29913
|
1070 |
png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red,
|
|
2
|
1071 |
double green)
|
|
|
1072 |
{
|
|
10576
|
1073 |
png_set_rgb_to_gray_fixed(png_ptr, error_action,
|
|
|
1074 |
png_fixed(png_ptr, red, "rgb to gray red coefficient"),
|
|
|
1075 |
png_fixed(png_ptr, green, "rgb to gray green coefficient"));
|
|
2
|
1076 |
}
|
|
10576
|
1077 |
#endif /* FLOATING POINT */
|
|
|
1078 |
|
|
29913
|
1079 |
#endif /* RGB_TO_GRAY */
|
|
2
|
1080 |
|
|
|
1081 |
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
|
|
10576
|
1082 |
defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
|
|
2
|
1083 |
void PNGAPI
|
|
29913
|
1084 |
png_set_read_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
|
|
10576
|
1085 |
read_user_transform_fn)
|
|
2
|
1086 |
{
|
|
10576
|
1087 |
png_debug(1, "in png_set_read_user_transform_fn");
|
|
|
1088 |
|
|
|
1089 |
#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
|
|
2
|
1090 |
png_ptr->transformations |= PNG_USER_TRANSFORM;
|
|
|
1091 |
png_ptr->read_user_transform_fn = read_user_transform_fn;
|
|
|
1092 |
#endif
|
|
10576
|
1093 |
}
|
|
2
|
1094 |
#endif
|
|
10576
|
1095 |
|
|
|
1096 |
#ifdef PNG_READ_TRANSFORMS_SUPPORTED
|
|
|
1097 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
|
1098 |
/* In the case of gamma transformations only do transformations on images where
|
|
|
1099 |
* the [file] gamma and screen_gamma are not close reciprocals, otherwise it
|
|
|
1100 |
* slows things down slightly, and also needlessly introduces small errors.
|
|
|
1101 |
*/
|
|
|
1102 |
static int /* PRIVATE */
|
|
|
1103 |
png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma)
|
|
|
1104 |
{
|
|
|
1105 |
/* PNG_GAMMA_THRESHOLD is the threshold for performing gamma
|
|
|
1106 |
* correction as a difference of the overall transform from 1.0
|
|
|
1107 |
*
|
|
|
1108 |
* We want to compare the threshold with s*f - 1, if we get
|
|
|
1109 |
* overflow here it is because of wacky gamma values so we
|
|
|
1110 |
* turn on processing anyway.
|
|
|
1111 |
*/
|
|
|
1112 |
png_fixed_point gtest;
|
|
|
1113 |
return !png_muldiv(>est, screen_gamma, file_gamma, PNG_FP_1) ||
|
|
|
1114 |
png_gamma_significant(gtest);
|
|
2
|
1115 |
}
|
|
|
1116 |
#endif
|
|
|
1117 |
|
|
|
1118 |
/* Initialize everything needed for the read. This includes modifying
|
|
|
1119 |
* the palette.
|
|
|
1120 |
*/
|
|
10576
|
1121 |
|
|
29913
|
1122 |
/* For the moment 'png_init_palette_transformations' and
|
|
10576
|
1123 |
* 'png_init_rgb_transformations' only do some flag canceling optimizations.
|
|
|
1124 |
* The intent is that these two routines should have palette or rgb operations
|
|
|
1125 |
* extracted from 'png_init_read_transformations'.
|
|
|
1126 |
*/
|
|
|
1127 |
static void /* PRIVATE */
|
|
29913
|
1128 |
png_init_palette_transformations(png_structrp png_ptr)
|
|
2
|
1129 |
{
|
|
10576
|
1130 |
/* Called to handle the (input) palette case. In png_do_read_transformations
|
|
|
1131 |
* the first step is to expand the palette if requested, so this code must
|
|
|
1132 |
* take care to only make changes that are invariant with respect to the
|
|
|
1133 |
* palette expansion, or only do them if there is no expansion.
|
|
|
1134 |
*
|
|
|
1135 |
* STRIP_ALPHA has already been handled in the caller (by setting num_trans
|
|
|
1136 |
* to 0.)
|
|
|
1137 |
*/
|
|
|
1138 |
int input_has_alpha = 0;
|
|
|
1139 |
int input_has_transparency = 0;
|
|
|
1140 |
|
|
|
1141 |
if (png_ptr->num_trans > 0)
|
|
|
1142 |
{
|
|
|
1143 |
int i;
|
|
|
1144 |
|
|
|
1145 |
/* Ignore if all the entries are opaque (unlikely!) */
|
|
|
1146 |
for (i=0; i<png_ptr->num_trans; ++i)
|
|
29913
|
1147 |
{
|
|
10576
|
1148 |
if (png_ptr->trans_alpha[i] == 255)
|
|
|
1149 |
continue;
|
|
|
1150 |
else if (png_ptr->trans_alpha[i] == 0)
|
|
|
1151 |
input_has_transparency = 1;
|
|
|
1152 |
else
|
|
29913
|
1153 |
{
|
|
|
1154 |
input_has_transparency = 1;
|
|
10576
|
1155 |
input_has_alpha = 1;
|
|
29913
|
1156 |
break;
|
|
|
1157 |
}
|
|
|
1158 |
}
|
|
10576
|
1159 |
}
|
|
|
1160 |
|
|
|
1161 |
/* If no alpha we can optimize. */
|
|
29913
|
1162 |
if (input_has_alpha == 0)
|
|
10576
|
1163 |
{
|
|
|
1164 |
/* Any alpha means background and associative alpha processing is
|
|
29913
|
1165 |
* required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
|
|
10576
|
1166 |
* and ENCODE_ALPHA are irrelevant.
|
|
|
1167 |
*/
|
|
|
1168 |
png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
|
|
1169 |
png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
|
|
1170 |
|
|
29913
|
1171 |
if (input_has_transparency == 0)
|
|
10576
|
1172 |
png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
|
|
|
1173 |
}
|
|
2
|
1174 |
|
|
|
1175 |
#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
10576
|
1176 |
/* png_set_background handling - deals with the complexity of whether the
|
|
|
1177 |
* background color is in the file format or the screen format in the case
|
|
|
1178 |
* where an 'expand' will happen.
|
|
2
|
1179 |
*/
|
|
10576
|
1180 |
|
|
|
1181 |
/* The following code cannot be entered in the alpha pre-multiplication case
|
|
|
1182 |
* because PNG_BACKGROUND_EXPAND is cancelled below.
|
|
|
1183 |
*/
|
|
29913
|
1184 |
if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 &&
|
|
|
1185 |
(png_ptr->transformations & PNG_EXPAND) != 0)
|
|
2
|
1186 |
{
|
|
|
1187 |
{
|
|
10576
|
1188 |
png_ptr->background.red =
|
|
|
1189 |
png_ptr->palette[png_ptr->background.index].red;
|
|
|
1190 |
png_ptr->background.green =
|
|
|
1191 |
png_ptr->palette[png_ptr->background.index].green;
|
|
|
1192 |
png_ptr->background.blue =
|
|
|
1193 |
png_ptr->palette[png_ptr->background.index].blue;
|
|
|
1194 |
|
|
|
1195 |
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
|
|
29913
|
1196 |
if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
|
|
10576
|
1197 |
{
|
|
29913
|
1198 |
if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0)
|
|
10576
|
1199 |
{
|
|
|
1200 |
/* Invert the alpha channel (in tRNS) unless the pixels are
|
|
|
1201 |
* going to be expanded, in which case leave it for later
|
|
|
1202 |
*/
|
|
|
1203 |
int i, istop = png_ptr->num_trans;
|
|
|
1204 |
|
|
|
1205 |
for (i=0; i<istop; i++)
|
|
|
1206 |
png_ptr->trans_alpha[i] = (png_byte)(255 -
|
|
|
1207 |
png_ptr->trans_alpha[i]);
|
|
|
1208 |
}
|
|
|
1209 |
}
|
|
29913
|
1210 |
#endif /* READ_INVERT_ALPHA */
|
|
10576
|
1211 |
}
|
|
|
1212 |
} /* background expand and (therefore) no alpha association. */
|
|
29913
|
1213 |
#endif /* READ_EXPAND && READ_BACKGROUND */
|
|
10576
|
1214 |
}
|
|
|
1215 |
|
|
|
1216 |
static void /* PRIVATE */
|
|
29913
|
1217 |
png_init_rgb_transformations(png_structrp png_ptr)
|
|
10576
|
1218 |
{
|
|
|
1219 |
/* Added to libpng-1.5.4: check the color type to determine whether there
|
|
|
1220 |
* is any alpha or transparency in the image and simply cancel the
|
|
|
1221 |
* background and alpha mode stuff if there isn't.
|
|
|
1222 |
*/
|
|
|
1223 |
int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0;
|
|
|
1224 |
int input_has_transparency = png_ptr->num_trans > 0;
|
|
|
1225 |
|
|
|
1226 |
/* If no alpha we can optimize. */
|
|
29913
|
1227 |
if (input_has_alpha == 0)
|
|
10576
|
1228 |
{
|
|
|
1229 |
/* Any alpha means background and associative alpha processing is
|
|
29913
|
1230 |
* required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
|
|
10576
|
1231 |
* and ENCODE_ALPHA are irrelevant.
|
|
|
1232 |
*/
|
|
|
1233 |
# ifdef PNG_READ_ALPHA_MODE_SUPPORTED
|
|
|
1234 |
png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
|
|
1235 |
png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
|
|
1236 |
# endif
|
|
|
1237 |
|
|
29913
|
1238 |
if (input_has_transparency == 0)
|
|
10576
|
1239 |
png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
|
|
|
1240 |
}
|
|
|
1241 |
|
|
|
1242 |
#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
|
1243 |
/* png_set_background handling - deals with the complexity of whether the
|
|
|
1244 |
* background color is in the file format or the screen format in the case
|
|
|
1245 |
* where an 'expand' will happen.
|
|
|
1246 |
*/
|
|
|
1247 |
|
|
|
1248 |
/* The following code cannot be entered in the alpha pre-multiplication case
|
|
|
1249 |
* because PNG_BACKGROUND_EXPAND is cancelled below.
|
|
|
1250 |
*/
|
|
29913
|
1251 |
if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 &&
|
|
|
1252 |
(png_ptr->transformations & PNG_EXPAND) != 0 &&
|
|
|
1253 |
(png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
|
|
10576
|
1254 |
/* i.e., GRAY or GRAY_ALPHA */
|
|
|
1255 |
{
|
|
|
1256 |
{
|
|
|
1257 |
/* Expand background and tRNS chunks */
|
|
29913
|
1258 |
int gray = png_ptr->background.gray;
|
|
|
1259 |
int trans_gray = png_ptr->trans_color.gray;
|
|
|
1260 |
|
|
2
|
1261 |
switch (png_ptr->bit_depth)
|
|
|
1262 |
{
|
|
|
1263 |
case 1:
|
|
29913
|
1264 |
gray *= 0xff;
|
|
|
1265 |
trans_gray *= 0xff;
|
|
2
|
1266 |
break;
|
|
10576
|
1267 |
|
|
2
|
1268 |
case 2:
|
|
29913
|
1269 |
gray *= 0x55;
|
|
|
1270 |
trans_gray *= 0x55;
|
|
2
|
1271 |
break;
|
|
10576
|
1272 |
|
|
2
|
1273 |
case 4:
|
|
29913
|
1274 |
gray *= 0x11;
|
|
|
1275 |
trans_gray *= 0x11;
|
|
2
|
1276 |
break;
|
|
10576
|
1277 |
|
|
|
1278 |
default:
|
|
|
1279 |
|
|
2
|
1280 |
case 8:
|
|
29913
|
1281 |
/* FALL THROUGH (Already 8 bits) */
|
|
10576
|
1282 |
|
|
2
|
1283 |
case 16:
|
|
29913
|
1284 |
/* Already a full 16 bits */
|
|
2
|
1285 |
break;
|
|
|
1286 |
}
|
|
29913
|
1287 |
|
|
|
1288 |
png_ptr->background.red = png_ptr->background.green =
|
|
|
1289 |
png_ptr->background.blue = (png_uint_16)gray;
|
|
|
1290 |
|
|
|
1291 |
if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0)
|
|
|
1292 |
{
|
|
|
1293 |
png_ptr->trans_color.red = png_ptr->trans_color.green =
|
|
|
1294 |
png_ptr->trans_color.blue = (png_uint_16)trans_gray;
|
|
|
1295 |
}
|
|
2
|
1296 |
}
|
|
10576
|
1297 |
} /* background expand and (therefore) no alpha association. */
|
|
29913
|
1298 |
#endif /* READ_EXPAND && READ_BACKGROUND */
|
|
10576
|
1299 |
}
|
|
|
1300 |
|
|
|
1301 |
void /* PRIVATE */
|
|
29913
|
1302 |
png_init_read_transformations(png_structrp png_ptr)
|
|
10576
|
1303 |
{
|
|
|
1304 |
png_debug(1, "in png_init_read_transformations");
|
|
|
1305 |
|
|
|
1306 |
/* This internal function is called from png_read_start_row in pngrutil.c
|
|
|
1307 |
* and it is called before the 'rowbytes' calculation is done, so the code
|
|
|
1308 |
* in here can change or update the transformations flags.
|
|
|
1309 |
*
|
|
|
1310 |
* First do updates that do not depend on the details of the PNG image data
|
|
|
1311 |
* being processed.
|
|
|
1312 |
*/
|
|
|
1313 |
|
|
|
1314 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
|
1315 |
/* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds
|
|
|
1316 |
* png_set_alpha_mode and this is another source for a default file gamma so
|
|
|
1317 |
* the test needs to be performed later - here. In addition prior to 1.5.4
|
|
|
1318 |
* the tests were repeated for the PALETTE color type here - this is no
|
|
|
1319 |
* longer necessary (and doesn't seem to have been necessary before.)
|
|
|
1320 |
*/
|
|
|
1321 |
{
|
|
|
1322 |
/* The following temporary indicates if overall gamma correction is
|
|
|
1323 |
* required.
|
|
|
1324 |
*/
|
|
|
1325 |
int gamma_correction = 0;
|
|
|
1326 |
|
|
29913
|
1327 |
if (png_ptr->colorspace.gamma != 0) /* has been set */
|
|
2
|
1328 |
{
|
|
10576
|
1329 |
if (png_ptr->screen_gamma != 0) /* screen set too */
|
|
29913
|
1330 |
gamma_correction = png_gamma_threshold(png_ptr->colorspace.gamma,
|
|
10576
|
1331 |
png_ptr->screen_gamma);
|
|
|
1332 |
|
|
|
1333 |
else
|
|
|
1334 |
/* Assume the output matches the input; a long time default behavior
|
|
|
1335 |
* of libpng, although the standard has nothing to say about this.
|
|
|
1336 |
*/
|
|
29913
|
1337 |
png_ptr->screen_gamma = png_reciprocal(png_ptr->colorspace.gamma);
|
|
10576
|
1338 |
}
|
|
|
1339 |
|
|
|
1340 |
else if (png_ptr->screen_gamma != 0)
|
|
|
1341 |
/* The converse - assume the file matches the screen, note that this
|
|
|
1342 |
* perhaps undesireable default can (from 1.5.4) be changed by calling
|
|
|
1343 |
* png_set_alpha_mode (even if the alpha handling mode isn't required
|
|
|
1344 |
* or isn't changed from the default.)
|
|
|
1345 |
*/
|
|
29913
|
1346 |
png_ptr->colorspace.gamma = png_reciprocal(png_ptr->screen_gamma);
|
|
10576
|
1347 |
|
|
|
1348 |
else /* neither are set */
|
|
|
1349 |
/* Just in case the following prevents any processing - file and screen
|
|
|
1350 |
* are both assumed to be linear and there is no way to introduce a
|
|
|
1351 |
* third gamma value other than png_set_background with 'UNIQUE', and,
|
|
|
1352 |
* prior to 1.5.4
|
|
|
1353 |
*/
|
|
29913
|
1354 |
png_ptr->screen_gamma = png_ptr->colorspace.gamma = PNG_FP_1;
|
|
|
1355 |
|
|
|
1356 |
/* We have a gamma value now. */
|
|
|
1357 |
png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
|
|
10576
|
1358 |
|
|
|
1359 |
/* Now turn the gamma transformation on or off as appropriate. Notice
|
|
|
1360 |
* that PNG_GAMMA just refers to the file->screen correction. Alpha
|
|
|
1361 |
* composition may independently cause gamma correction because it needs
|
|
|
1362 |
* linear data (e.g. if the file has a gAMA chunk but the screen gamma
|
|
|
1363 |
* hasn't been specified.) In any case this flag may get turned off in
|
|
|
1364 |
* the code immediately below if the transform can be handled outside the
|
|
|
1365 |
* row loop.
|
|
|
1366 |
*/
|
|
29913
|
1367 |
if (gamma_correction != 0)
|
|
10576
|
1368 |
png_ptr->transformations |= PNG_GAMMA;
|
|
|
1369 |
|
|
|
1370 |
else
|
|
|
1371 |
png_ptr->transformations &= ~PNG_GAMMA;
|
|
|
1372 |
}
|
|
2
|
1373 |
#endif
|
|
10576
|
1374 |
|
|
|
1375 |
/* Certain transformations have the effect of preventing other
|
|
29913
|
1376 |
* transformations that happen afterward in png_do_read_transformations;
|
|
10576
|
1377 |
* resolve the interdependencies here. From the code of
|
|
|
1378 |
* png_do_read_transformations the order is:
|
|
|
1379 |
*
|
|
|
1380 |
* 1) PNG_EXPAND (including PNG_EXPAND_tRNS)
|
|
|
1381 |
* 2) PNG_STRIP_ALPHA (if no compose)
|
|
|
1382 |
* 3) PNG_RGB_TO_GRAY
|
|
|
1383 |
* 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY
|
|
|
1384 |
* 5) PNG_COMPOSE
|
|
|
1385 |
* 6) PNG_GAMMA
|
|
|
1386 |
* 7) PNG_STRIP_ALPHA (if compose)
|
|
|
1387 |
* 8) PNG_ENCODE_ALPHA
|
|
|
1388 |
* 9) PNG_SCALE_16_TO_8
|
|
|
1389 |
* 10) PNG_16_TO_8
|
|
|
1390 |
* 11) PNG_QUANTIZE (converts to palette)
|
|
|
1391 |
* 12) PNG_EXPAND_16
|
|
|
1392 |
* 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY
|
|
|
1393 |
* 14) PNG_INVERT_MONO
|
|
29913
|
1394 |
* 15) PNG_INVERT_ALPHA
|
|
|
1395 |
* 16) PNG_SHIFT
|
|
|
1396 |
* 17) PNG_PACK
|
|
|
1397 |
* 18) PNG_BGR
|
|
|
1398 |
* 19) PNG_PACKSWAP
|
|
|
1399 |
* 20) PNG_FILLER (includes PNG_ADD_ALPHA)
|
|
10576
|
1400 |
* 21) PNG_SWAP_ALPHA
|
|
|
1401 |
* 22) PNG_SWAP_BYTES
|
|
|
1402 |
* 23) PNG_USER_TRANSFORM [must be last]
|
|
|
1403 |
*/
|
|
|
1404 |
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
|
|
29913
|
1405 |
if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
|
|
|
1406 |
(png_ptr->transformations & PNG_COMPOSE) == 0)
|
|
10576
|
1407 |
{
|
|
|
1408 |
/* Stripping the alpha channel happens immediately after the 'expand'
|
|
|
1409 |
* transformations, before all other transformation, so it cancels out
|
|
|
1410 |
* the alpha handling. It has the side effect negating the effect of
|
|
|
1411 |
* PNG_EXPAND_tRNS too:
|
|
|
1412 |
*/
|
|
|
1413 |
png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA |
|
|
|
1414 |
PNG_EXPAND_tRNS);
|
|
|
1415 |
png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
|
|
1416 |
|
|
|
1417 |
/* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen
|
|
|
1418 |
* so transparency information would remain just so long as it wasn't
|
|
|
1419 |
* expanded. This produces unexpected API changes if the set of things
|
|
|
1420 |
* that do PNG_EXPAND_tRNS changes (perfectly possible given the
|
|
|
1421 |
* documentation - which says ask for what you want, accept what you
|
|
|
1422 |
* get.) This makes the behavior consistent from 1.5.4:
|
|
|
1423 |
*/
|
|
|
1424 |
png_ptr->num_trans = 0;
|
|
|
1425 |
}
|
|
|
1426 |
#endif /* STRIP_ALPHA supported, no COMPOSE */
|
|
|
1427 |
|
|
|
1428 |
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
|
|
|
1429 |
/* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA
|
|
|
1430 |
* settings will have no effect.
|
|
|
1431 |
*/
|
|
29913
|
1432 |
if (png_gamma_significant(png_ptr->screen_gamma) == 0)
|
|
10576
|
1433 |
{
|
|
|
1434 |
png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
|
|
1435 |
png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
|
2
|
1436 |
}
|
|
|
1437 |
#endif
|
|
|
1438 |
|
|
29913
|
1439 |
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
|
|
1440 |
/* Make sure the coefficients for the rgb to gray conversion are set
|
|
|
1441 |
* appropriately.
|
|
|
1442 |
*/
|
|
|
1443 |
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
|
|
|
1444 |
png_colorspace_set_rgb_coefficients(png_ptr);
|
|
|
1445 |
#endif
|
|
|
1446 |
|
|
|
1447 |
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
|
|
1448 |
#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
10576
|
1449 |
/* Detect gray background and attempt to enable optimization for
|
|
|
1450 |
* gray --> RGB case.
|
|
|
1451 |
*
|
|
|
1452 |
* Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
|
|
|
1453 |
* RGB_ALPHA (in which case need_expand is superfluous anyway), the
|
|
|
1454 |
* background color might actually be gray yet not be flagged as such.
|
|
|
1455 |
* This is not a problem for the current code, which uses
|
|
|
1456 |
* PNG_BACKGROUND_IS_GRAY only to decide when to do the
|
|
|
1457 |
* png_do_gray_to_rgb() transformation.
|
|
|
1458 |
*
|
|
|
1459 |
* TODO: this code needs to be revised to avoid the complexity and
|
|
|
1460 |
* interdependencies. The color type of the background should be recorded in
|
|
|
1461 |
* png_set_background, along with the bit depth, then the code has a record
|
|
|
1462 |
* of exactly what color space the background is currently in.
|
|
|
1463 |
*/
|
|
29913
|
1464 |
if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0)
|
|
10576
|
1465 |
{
|
|
|
1466 |
/* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if
|
|
29913
|
1467 |
* the file was grayscale the background value is gray.
|
|
10576
|
1468 |
*/
|
|
29913
|
1469 |
if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
|
|
10576
|
1470 |
png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
|
|
|
1471 |
}
|
|
|
1472 |
|
|
29913
|
1473 |
else if ((png_ptr->transformations & PNG_COMPOSE) != 0)
|
|
10576
|
1474 |
{
|
|
|
1475 |
/* PNG_COMPOSE: png_set_background was called with need_expand false,
|
|
|
1476 |
* so the color is in the color space of the output or png_set_alpha_mode
|
|
|
1477 |
* was called and the color is black. Ignore RGB_TO_GRAY because that
|
|
|
1478 |
* happens before GRAY_TO_RGB.
|
|
|
1479 |
*/
|
|
29913
|
1480 |
if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
|
|
10576
|
1481 |
{
|
|
|
1482 |
if (png_ptr->background.red == png_ptr->background.green &&
|
|
|
1483 |
png_ptr->background.red == png_ptr->background.blue)
|
|
|
1484 |
{
|
|
|
1485 |
png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
|
|
|
1486 |
png_ptr->background.gray = png_ptr->background.red;
|
|
|
1487 |
}
|
|
|
1488 |
}
|
|
|
1489 |
}
|
|
29913
|
1490 |
#endif /* READ_EXPAND && READ_BACKGROUND */
|
|
|
1491 |
#endif /* READ_GRAY_TO_RGB */
|
|
10576
|
1492 |
|
|
|
1493 |
/* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations
|
|
|
1494 |
* can be performed directly on the palette, and some (such as rgb to gray)
|
|
|
1495 |
* can be optimized inside the palette. This is particularly true of the
|
|
|
1496 |
* composite (background and alpha) stuff, which can be pretty much all done
|
|
|
1497 |
* in the palette even if the result is expanded to RGB or gray afterward.
|
|
|
1498 |
*
|
|
|
1499 |
* NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and
|
|
|
1500 |
* earlier and the palette stuff is actually handled on the first row. This
|
|
|
1501 |
* leads to the reported bug that the palette returned by png_get_PLTE is not
|
|
|
1502 |
* updated.
|
|
|
1503 |
*/
|
|
|
1504 |
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
|
1505 |
png_init_palette_transformations(png_ptr);
|
|
|
1506 |
|
|
|
1507 |
else
|
|
|
1508 |
png_init_rgb_transformations(png_ptr);
|
|
|
1509 |
|
|
|
1510 |
#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
|
|
|
1511 |
defined(PNG_READ_EXPAND_16_SUPPORTED)
|
|
29913
|
1512 |
if ((png_ptr->transformations & PNG_EXPAND_16) != 0 &&
|
|
|
1513 |
(png_ptr->transformations & PNG_COMPOSE) != 0 &&
|
|
|
1514 |
(png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 &&
|
|
|
1515 |
png_ptr->bit_depth != 16)
|
|
2
|
1516 |
{
|
|
10576
|
1517 |
/* TODO: fix this. Because the expand_16 operation is after the compose
|
|
|
1518 |
* handling the background color must be 8, not 16, bits deep, but the
|
|
|
1519 |
* application will supply a 16-bit value so reduce it here.
|
|
|
1520 |
*
|
|
|
1521 |
* The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at
|
|
|
1522 |
* present, so that case is ok (until do_expand_16 is moved.)
|
|
|
1523 |
*
|
|
|
1524 |
* NOTE: this discards the low 16 bits of the user supplied background
|
|
|
1525 |
* color, but until expand_16 works properly there is no choice!
|
|
|
1526 |
*/
|
|
29913
|
1527 |
# define CHOP(x) (x)=((png_uint_16)PNG_DIV257(x))
|
|
10576
|
1528 |
CHOP(png_ptr->background.red);
|
|
|
1529 |
CHOP(png_ptr->background.green);
|
|
|
1530 |
CHOP(png_ptr->background.blue);
|
|
|
1531 |
CHOP(png_ptr->background.gray);
|
|
|
1532 |
# undef CHOP
|
|
2
|
1533 |
}
|
|
29913
|
1534 |
#endif /* READ_BACKGROUND && READ_EXPAND_16 */
|
|
|
1535 |
|
|
|
1536 |
#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
|
|
|
1537 |
(defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \
|
|
|
1538 |
defined(PNG_READ_STRIP_16_TO_8_SUPPORTED))
|
|
|
1539 |
if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) != 0 &&
|
|
|
1540 |
(png_ptr->transformations & PNG_COMPOSE) != 0 &&
|
|
|
1541 |
(png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 &&
|
|
|
1542 |
png_ptr->bit_depth == 16)
|
|
|
1543 |
{
|
|
|
1544 |
/* On the other hand, if a 16-bit file is to be reduced to 8-bits per
|
|
|
1545 |
* component this will also happen after PNG_COMPOSE and so the background
|
|
|
1546 |
* color must be pre-expanded here.
|
|
|
1547 |
*
|
|
|
1548 |
* TODO: fix this too.
|
|
|
1549 |
*/
|
|
|
1550 |
png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257);
|
|
|
1551 |
png_ptr->background.green =
|
|
|
1552 |
(png_uint_16)(png_ptr->background.green * 257);
|
|
|
1553 |
png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257);
|
|
|
1554 |
png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257);
|
|
|
1555 |
}
|
|
|
1556 |
#endif
|
|
10576
|
1557 |
|
|
|
1558 |
/* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the
|
|
|
1559 |
* background support (see the comments in scripts/pnglibconf.dfa), this
|
|
|
1560 |
* allows pre-multiplication of the alpha channel to be implemented as
|
|
|
1561 |
* compositing on black. This is probably sub-optimal and has been done in
|
|
|
1562 |
* 1.5.4 betas simply to enable external critique and testing (i.e. to
|
|
|
1563 |
* implement the new API quickly, without lots of internal changes.)
|
|
|
1564 |
*/
|
|
|
1565 |
|
|
|
1566 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
|
1567 |
# ifdef PNG_READ_BACKGROUND_SUPPORTED
|
|
|
1568 |
/* Includes ALPHA_MODE */
|
|
|
1569 |
png_ptr->background_1 = png_ptr->background;
|
|
|
1570 |
# endif
|
|
|
1571 |
|
|
|
1572 |
/* This needs to change - in the palette image case a whole set of tables are
|
|
|
1573 |
* built when it would be quicker to just calculate the correct value for
|
|
|
1574 |
* each palette entry directly. Also, the test is too tricky - why check
|
|
|
1575 |
* PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that
|
|
|
1576 |
* PNG_GAMMA is cancelled even if the gamma is known? The test excludes the
|
|
|
1577 |
* PNG_COMPOSE case, so apparently if there is no *overall* gamma correction
|
|
|
1578 |
* the gamma tables will not be built even if composition is required on a
|
|
|
1579 |
* gamma encoded value.
|
|
|
1580 |
*
|
|
|
1581 |
* In 1.5.4 this is addressed below by an additional check on the individual
|
|
|
1582 |
* file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the
|
|
|
1583 |
* tables.
|
|
|
1584 |
*/
|
|
29913
|
1585 |
if ((png_ptr->transformations & PNG_GAMMA) != 0 ||
|
|
|
1586 |
((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0 &&
|
|
|
1587 |
(png_gamma_significant(png_ptr->colorspace.gamma) != 0 ||
|
|
|
1588 |
png_gamma_significant(png_ptr->screen_gamma) != 0)) ||
|
|
|
1589 |
((png_ptr->transformations & PNG_COMPOSE) != 0 &&
|
|
|
1590 |
(png_gamma_significant(png_ptr->colorspace.gamma) != 0 ||
|
|
|
1591 |
png_gamma_significant(png_ptr->screen_gamma) != 0
|
|
10576
|
1592 |
# ifdef PNG_READ_BACKGROUND_SUPPORTED
|
|
29913
|
1593 |
|| (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE &&
|
|
|
1594 |
png_gamma_significant(png_ptr->background_gamma) != 0)
|
|
10576
|
1595 |
# endif
|
|
29913
|
1596 |
)) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 &&
|
|
|
1597 |
png_gamma_significant(png_ptr->screen_gamma) != 0))
|
|
2
|
1598 |
{
|
|
10576
|
1599 |
png_build_gamma_table(png_ptr, png_ptr->bit_depth);
|
|
|
1600 |
|
|
|
1601 |
#ifdef PNG_READ_BACKGROUND_SUPPORTED
|
|
29913
|
1602 |
if ((png_ptr->transformations & PNG_COMPOSE) != 0)
|
|
2
|
1603 |
{
|
|
29913
|
1604 |
/* Issue a warning about this combination: because RGB_TO_GRAY is
|
|
|
1605 |
* optimized to do the gamma transform if present yet do_background has
|
|
|
1606 |
* to do the same thing if both options are set a
|
|
|
1607 |
* double-gamma-correction happens. This is true in all versions of
|
|
|
1608 |
* libpng to date.
|
|
|
1609 |
*/
|
|
|
1610 |
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
|
|
|
1611 |
png_warning(png_ptr,
|
|
|
1612 |
"libpng does not support gamma+background+rgb_to_gray");
|
|
|
1613 |
|
|
|
1614 |
if ((png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) != 0)
|
|
2
|
1615 |
{
|
|
10576
|
1616 |
/* We don't get to here unless there is a tRNS chunk with non-opaque
|
|
|
1617 |
* entries - see the checking code at the start of this function.
|
|
|
1618 |
*/
|
|
2
|
1619 |
png_color back, back_1;
|
|
|
1620 |
png_colorp palette = png_ptr->palette;
|
|
|
1621 |
int num_palette = png_ptr->num_palette;
|
|
|
1622 |
int i;
|
|
|
1623 |
if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
|
|
|
1624 |
{
|
|
10576
|
1625 |
|
|
2
|
1626 |
back.red = png_ptr->gamma_table[png_ptr->background.red];
|
|
|
1627 |
back.green = png_ptr->gamma_table[png_ptr->background.green];
|
|
|
1628 |
back.blue = png_ptr->gamma_table[png_ptr->background.blue];
|
|
|
1629 |
|
|
|
1630 |
back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
|
|
|
1631 |
back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
|
|
|
1632 |
back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
|
|
|
1633 |
}
|
|
|
1634 |
else
|
|
|
1635 |
{
|
|
10576
|
1636 |
png_fixed_point g, gs;
|
|
2
|
1637 |
|
|
|
1638 |
switch (png_ptr->background_gamma_type)
|
|
|
1639 |
{
|
|
|
1640 |
case PNG_BACKGROUND_GAMMA_SCREEN:
|
|
|
1641 |
g = (png_ptr->screen_gamma);
|
|
10576
|
1642 |
gs = PNG_FP_1;
|
|
2
|
1643 |
break;
|
|
10576
|
1644 |
|
|
2
|
1645 |
case PNG_BACKGROUND_GAMMA_FILE:
|
|
29913
|
1646 |
g = png_reciprocal(png_ptr->colorspace.gamma);
|
|
|
1647 |
gs = png_reciprocal2(png_ptr->colorspace.gamma,
|
|
10576
|
1648 |
png_ptr->screen_gamma);
|
|
2
|
1649 |
break;
|
|
10576
|
1650 |
|
|
2
|
1651 |
case PNG_BACKGROUND_GAMMA_UNIQUE:
|
|
10576
|
1652 |
g = png_reciprocal(png_ptr->background_gamma);
|
|
|
1653 |
gs = png_reciprocal2(png_ptr->background_gamma,
|
|
|
1654 |
png_ptr->screen_gamma);
|
|
2
|
1655 |
break;
|
|
|
1656 |
default:
|
|
10576
|
1657 |
g = PNG_FP_1; /* back_1 */
|
|
|
1658 |
gs = PNG_FP_1; /* back */
|
|
|
1659 |
break;
|
|
2
|
1660 |
}
|
|
|
1661 |
|
|
29913
|
1662 |
if (png_gamma_significant(gs) != 0)
|
|
10576
|
1663 |
{
|
|
|
1664 |
back.red = png_gamma_8bit_correct(png_ptr->background.red,
|
|
|
1665 |
gs);
|
|
|
1666 |
back.green = png_gamma_8bit_correct(png_ptr->background.green,
|
|
|
1667 |
gs);
|
|
|
1668 |
back.blue = png_gamma_8bit_correct(png_ptr->background.blue,
|
|
|
1669 |
gs);
|
|
|
1670 |
}
|
|
|
1671 |
|
|
|
1672 |
else
|
|
2
|
1673 |
{
|
|
|
1674 |
back.red = (png_byte)png_ptr->background.red;
|
|
|
1675 |
back.green = (png_byte)png_ptr->background.green;
|
|
|
1676 |
back.blue = (png_byte)png_ptr->background.blue;
|
|
|
1677 |
}
|
|
10576
|
1678 |
|
|
29913
|
1679 |
if (png_gamma_significant(g) != 0)
|
|
10576
|
1680 |
{
|
|
|
1681 |
back_1.red = png_gamma_8bit_correct(png_ptr->background.red,
|
|
|
1682 |
g);
|
|
|
1683 |
back_1.green = png_gamma_8bit_correct(
|
|
|
1684 |
png_ptr->background.green, g);
|
|
|
1685 |
back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue,
|
|
|
1686 |
g);
|
|
|
1687 |
}
|
|
|
1688 |
|
|
2
|
1689 |
else
|
|
|
1690 |
{
|
|
10576
|
1691 |
back_1.red = (png_byte)png_ptr->background.red;
|
|
|
1692 |
back_1.green = (png_byte)png_ptr->background.green;
|
|
|
1693 |
back_1.blue = (png_byte)png_ptr->background.blue;
|
|
2
|
1694 |
}
|
|
|
1695 |
}
|
|
10576
|
1696 |
|
|
2
|
1697 |
for (i = 0; i < num_palette; i++)
|
|
|
1698 |
{
|
|
10576
|
1699 |
if (i < (int)png_ptr->num_trans &&
|
|
|
1700 |
png_ptr->trans_alpha[i] != 0xff)
|
|
2
|
1701 |
{
|
|
10576
|
1702 |
if (png_ptr->trans_alpha[i] == 0)
|
|
2
|
1703 |
{
|
|
|
1704 |
palette[i] = back;
|
|
|
1705 |
}
|
|
10576
|
1706 |
else /* if (png_ptr->trans_alpha[i] != 0xff) */
|
|
2
|
1707 |
{
|
|
|
1708 |
png_byte v, w;
|
|
|
1709 |
|
|
|
1710 |
v = png_ptr->gamma_to_1[palette[i].red];
|
|
10576
|
1711 |
png_composite(w, v, png_ptr->trans_alpha[i], back_1.red);
|
|
2
|
1712 |
palette[i].red = png_ptr->gamma_from_1[w];
|
|
|
1713 |
|
|
|
1714 |
v = png_ptr->gamma_to_1[palette[i].green];
|
|
10576
|
1715 |
png_composite(w, v, png_ptr->trans_alpha[i], back_1.green);
|
|
2
|
1716 |
palette[i].green = png_ptr->gamma_from_1[w];
|
|
|
1717 |
|
|
|
1718 |
v = png_ptr->gamma_to_1[palette[i].blue];
|
|
10576
|
1719 |
png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue);
|
|
2
|
1720 |
palette[i].blue = png_ptr->gamma_from_1[w];
|
|
|
1721 |
}
|
|
|
1722 |
}
|
|
|
1723 |
else
|
|
|
1724 |
{
|
|
|
1725 |
palette[i].red = png_ptr->gamma_table[palette[i].red];
|
|
|
1726 |
palette[i].green = png_ptr->gamma_table[palette[i].green];
|
|
|
1727 |
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
|
|
|
1728 |
}
|
|
|
1729 |
}
|
|
10576
|
1730 |
|
|
|
1731 |
/* Prevent the transformations being done again.
|
|
|
1732 |
*
|
|
29913
|
1733 |
* NOTE: this is highly dubious; it removes the transformations in
|
|
10576
|
1734 |
* place. This seems inconsistent with the general treatment of the
|
|
|
1735 |
* transformations elsewhere.
|
|
|
1736 |
*/
|
|
|
1737 |
png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA);
|
|
|
1738 |
} /* color_type == PNG_COLOR_TYPE_PALETTE */
|
|
|
1739 |
|
|
2
|
1740 |
/* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
|
|
10576
|
1741 |
else /* color_type != PNG_COLOR_TYPE_PALETTE */
|
|
2
|
1742 |
{
|
|
29913
|
1743 |
int gs_sig, g_sig;
|
|
|
1744 |
png_fixed_point g = PNG_FP_1; /* Correction to linear */
|
|
|
1745 |
png_fixed_point gs = PNG_FP_1; /* Correction to screen */
|
|
2
|
1746 |
|
|
|
1747 |
switch (png_ptr->background_gamma_type)
|
|
|
1748 |
{
|
|
|
1749 |
case PNG_BACKGROUND_GAMMA_SCREEN:
|
|
10576
|
1750 |
g = png_ptr->screen_gamma;
|
|
|
1751 |
/* gs = PNG_FP_1; */
|
|
2
|
1752 |
break;
|
|
10576
|
1753 |
|
|
2
|
1754 |
case PNG_BACKGROUND_GAMMA_FILE:
|
|
29913
|
1755 |
g = png_reciprocal(png_ptr->colorspace.gamma);
|
|
|
1756 |
gs = png_reciprocal2(png_ptr->colorspace.gamma,
|
|
|
1757 |
png_ptr->screen_gamma);
|
|
2
|
1758 |
break;
|
|
10576
|
1759 |
|
|
2
|
1760 |
case PNG_BACKGROUND_GAMMA_UNIQUE:
|
|
10576
|
1761 |
g = png_reciprocal(png_ptr->background_gamma);
|
|
|
1762 |
gs = png_reciprocal2(png_ptr->background_gamma,
|
|
|
1763 |
png_ptr->screen_gamma);
|
|
2
|
1764 |
break;
|
|
10576
|
1765 |
|
|
|
1766 |
default:
|
|
|
1767 |
png_error(png_ptr, "invalid background gamma type");
|
|
2
|
1768 |
}
|
|
|
1769 |
|
|
29913
|
1770 |
g_sig = png_gamma_significant(g);
|
|
|
1771 |
gs_sig = png_gamma_significant(gs);
|
|
|
1772 |
|
|
|
1773 |
if (g_sig != 0)
|
|
|
1774 |
png_ptr->background_1.gray = png_gamma_correct(png_ptr,
|
|
|
1775 |
png_ptr->background.gray, g);
|
|
|
1776 |
|
|
|
1777 |
if (gs_sig != 0)
|
|
|
1778 |
png_ptr->background.gray = png_gamma_correct(png_ptr,
|
|
|
1779 |
png_ptr->background.gray, gs);
|
|
2
|
1780 |
|
|
|
1781 |
if ((png_ptr->background.red != png_ptr->background.green) ||
|
|
|
1782 |
(png_ptr->background.red != png_ptr->background.blue) ||
|
|
|
1783 |
(png_ptr->background.red != png_ptr->background.gray))
|
|
|
1784 |
{
|
|
|
1785 |
/* RGB or RGBA with color background */
|
|
29913
|
1786 |
if (g_sig != 0)
|
|
|
1787 |
{
|
|
|
1788 |
png_ptr->background_1.red = png_gamma_correct(png_ptr,
|
|
|
1789 |
png_ptr->background.red, g);
|
|
|
1790 |
|
|
|
1791 |
png_ptr->background_1.green = png_gamma_correct(png_ptr,
|
|
|
1792 |
png_ptr->background.green, g);
|
|
|
1793 |
|
|
|
1794 |
png_ptr->background_1.blue = png_gamma_correct(png_ptr,
|
|
|
1795 |
png_ptr->background.blue, g);
|
|
|
1796 |
}
|
|
|
1797 |
|
|
|
1798 |
if (gs_sig != 0)
|
|
|
1799 |
{
|
|
|
1800 |
png_ptr->background.red = png_gamma_correct(png_ptr,
|
|
|
1801 |
png_ptr->background.red, gs);
|
|
|
1802 |
|
|
|
1803 |
png_ptr->background.green = png_gamma_correct(png_ptr,
|
|
|
1804 |
png_ptr->background.green, gs);
|
|
|
1805 |
|
|
|
1806 |
png_ptr->background.blue = png_gamma_correct(png_ptr,
|
|
|
1807 |
png_ptr->background.blue, gs);
|
|
|
1808 |
}
|
|
2
|
1809 |
}
|
|
10576
|
1810 |
|
|
2
|
1811 |
else
|
|
|
1812 |
{
|
|
|
1813 |
/* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
|
|
|
1814 |
png_ptr->background_1.red = png_ptr->background_1.green
|
|
10576
|
1815 |
= png_ptr->background_1.blue = png_ptr->background_1.gray;
|
|
|
1816 |
|
|
2
|
1817 |
png_ptr->background.red = png_ptr->background.green
|
|
10576
|
1818 |
= png_ptr->background.blue = png_ptr->background.gray;
|
|
2
|
1819 |
}
|
|
29913
|
1820 |
|
|
|
1821 |
/* The background is now in screen gamma: */
|
|
|
1822 |
png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN;
|
|
10576
|
1823 |
} /* color_type != PNG_COLOR_TYPE_PALETTE */
|
|
|
1824 |
}/* png_ptr->transformations & PNG_BACKGROUND */
|
|
|
1825 |
|
|
2
|
1826 |
else
|
|
10576
|
1827 |
/* Transformation does not include PNG_BACKGROUND */
|
|
29913
|
1828 |
#endif /* READ_BACKGROUND */
|
|
|
1829 |
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE
|
|
|
1830 |
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
|
|
1831 |
/* RGB_TO_GRAY needs to have non-gamma-corrected values! */
|
|
|
1832 |
&& ((png_ptr->transformations & PNG_EXPAND) == 0 ||
|
|
|
1833 |
(png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
|
|
|
1834 |
#endif
|
|
|
1835 |
)
|
|
2
|
1836 |
{
|
|
|
1837 |
png_colorp palette = png_ptr->palette;
|
|
|
1838 |
int num_palette = png_ptr->num_palette;
|
|
|
1839 |
int i;
|
|
|
1840 |
|
|
29913
|
1841 |
/* NOTE: there are other transformations that should probably be in
|
|
|
1842 |
* here too.
|
|
10576
|
1843 |
*/
|
|
2
|
1844 |
for (i = 0; i < num_palette; i++)
|
|
|
1845 |
{
|
|
|
1846 |
palette[i].red = png_ptr->gamma_table[palette[i].red];
|
|
|
1847 |
palette[i].green = png_ptr->gamma_table[palette[i].green];
|
|
|
1848 |
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
|
|
|
1849 |
}
|
|
10576
|
1850 |
|
|
|
1851 |
/* Done the gamma correction. */
|
|
|
1852 |
png_ptr->transformations &= ~PNG_GAMMA;
|
|
|
1853 |
} /* color_type == PALETTE && !PNG_BACKGROUND transformation */
|
|
2
|
1854 |
}
|
|
10576
|
1855 |
#ifdef PNG_READ_BACKGROUND_SUPPORTED
|
|
2
|
1856 |
else
|
|
|
1857 |
#endif
|
|
29913
|
1858 |
#endif /* READ_GAMMA */
|
|
10576
|
1859 |
|
|
|
1860 |
#ifdef PNG_READ_BACKGROUND_SUPPORTED
|
|
|
1861 |
/* No GAMMA transformation (see the hanging else 4 lines above) */
|
|
29913
|
1862 |
if ((png_ptr->transformations & PNG_COMPOSE) != 0 &&
|
|
10576
|
1863 |
(png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
|
|
2
|
1864 |
{
|
|
|
1865 |
int i;
|
|
|
1866 |
int istop = (int)png_ptr->num_trans;
|
|
|
1867 |
png_color back;
|
|
|
1868 |
png_colorp palette = png_ptr->palette;
|
|
|
1869 |
|
|
|
1870 |
back.red = (png_byte)png_ptr->background.red;
|
|
|
1871 |
back.green = (png_byte)png_ptr->background.green;
|
|
|
1872 |
back.blue = (png_byte)png_ptr->background.blue;
|
|
|
1873 |
|
|
|
1874 |
for (i = 0; i < istop; i++)
|
|
|
1875 |
{
|
|
10576
|
1876 |
if (png_ptr->trans_alpha[i] == 0)
|
|
2
|
1877 |
{
|
|
|
1878 |
palette[i] = back;
|
|
|
1879 |
}
|
|
10576
|
1880 |
|
|
|
1881 |
else if (png_ptr->trans_alpha[i] != 0xff)
|
|
2
|
1882 |
{
|
|
|
1883 |
/* The png_composite() macro is defined in png.h */
|
|
|
1884 |
png_composite(palette[i].red, palette[i].red,
|
|
10576
|
1885 |
png_ptr->trans_alpha[i], back.red);
|
|
|
1886 |
|
|
2
|
1887 |
png_composite(palette[i].green, palette[i].green,
|
|
10576
|
1888 |
png_ptr->trans_alpha[i], back.green);
|
|
|
1889 |
|
|
2
|
1890 |
png_composite(palette[i].blue, palette[i].blue,
|
|
10576
|
1891 |
png_ptr->trans_alpha[i], back.blue);
|
|
2
|
1892 |
}
|
|
|
1893 |
}
|
|
10576
|
1894 |
|
|
|
1895 |
png_ptr->transformations &= ~PNG_COMPOSE;
|
|
2
|
1896 |
}
|
|
29913
|
1897 |
#endif /* READ_BACKGROUND */
|
|
2
|
1898 |
|
|
10576
|
1899 |
#ifdef PNG_READ_SHIFT_SUPPORTED
|
|
29913
|
1900 |
if ((png_ptr->transformations & PNG_SHIFT) != 0 &&
|
|
|
1901 |
(png_ptr->transformations & PNG_EXPAND) == 0 &&
|
|
10576
|
1902 |
(png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
|
|
2
|
1903 |
{
|
|
29913
|
1904 |
int i;
|
|
|
1905 |
int istop = png_ptr->num_palette;
|
|
|
1906 |
int shift = 8 - png_ptr->sig_bit.red;
|
|
|
1907 |
|
|
|
1908 |
png_ptr->transformations &= ~PNG_SHIFT;
|
|
|
1909 |
|
|
|
1910 |
/* significant bits can be in the range 1 to 7 for a meaninful result, if
|
|
|
1911 |
* the number of significant bits is 0 then no shift is done (this is an
|
|
|
1912 |
* error condition which is silently ignored.)
|
|
|
1913 |
*/
|
|
|
1914 |
if (shift > 0 && shift < 8)
|
|
|
1915 |
for (i=0; i<istop; ++i)
|
|
|
1916 |
{
|
|
|
1917 |
int component = png_ptr->palette[i].red;
|
|
|
1918 |
|
|
|
1919 |
component >>= shift;
|
|
|
1920 |
png_ptr->palette[i].red = (png_byte)component;
|
|
|
1921 |
}
|
|
|
1922 |
|
|
|
1923 |
shift = 8 - png_ptr->sig_bit.green;
|
|
|
1924 |
if (shift > 0 && shift < 8)
|
|
|
1925 |
for (i=0; i<istop; ++i)
|
|
|
1926 |
{
|
|
|
1927 |
int component = png_ptr->palette[i].green;
|
|
|
1928 |
|
|
|
1929 |
component >>= shift;
|
|
|
1930 |
png_ptr->palette[i].green = (png_byte)component;
|
|
|
1931 |
}
|
|
|
1932 |
|
|
|
1933 |
shift = 8 - png_ptr->sig_bit.blue;
|
|
|
1934 |
if (shift > 0 && shift < 8)
|
|
|
1935 |
for (i=0; i<istop; ++i)
|
|
|
1936 |
{
|
|
|
1937 |
int component = png_ptr->palette[i].blue;
|
|
|
1938 |
|
|
|
1939 |
component >>= shift;
|
|
|
1940 |
png_ptr->palette[i].blue = (png_byte)component;
|
|
|
1941 |
}
|
|
2
|
1942 |
}
|
|
29913
|
1943 |
#endif /* READ_SHIFT */
|
|
2
|
1944 |
}
|
|
|
1945 |
|
|
|
1946 |
/* Modify the info structure to reflect the transformations. The
|
|
|
1947 |
* info should be updated so a PNG file could be written with it,
|
|
|
1948 |
* assuming the transformations result in valid PNG data.
|
|
|
1949 |
*/
|
|
|
1950 |
void /* PRIVATE */
|
|
29913
|
1951 |
png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
|
|
2
|
1952 |
{
|
|
10576
|
1953 |
png_debug(1, "in png_read_transform_info");
|
|
|
1954 |
|
|
|
1955 |
#ifdef PNG_READ_EXPAND_SUPPORTED
|
|
29913
|
1956 |
if ((png_ptr->transformations & PNG_EXPAND) != 0)
|
|
2
|
1957 |
{
|
|
|
1958 |
if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
|
1959 |
{
|
|
10576
|
1960 |
/* This check must match what actually happens in
|
|
|
1961 |
* png_do_expand_palette; if it ever checks the tRNS chunk to see if
|
|
|
1962 |
* it is all opaque we must do the same (at present it does not.)
|
|
|
1963 |
*/
|
|
|
1964 |
if (png_ptr->num_trans > 0)
|
|
2
|
1965 |
info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
|
|
10576
|
1966 |
|
|
2
|
1967 |
else
|
|
|
1968 |
info_ptr->color_type = PNG_COLOR_TYPE_RGB;
|
|
10576
|
1969 |
|
|
2
|
1970 |
info_ptr->bit_depth = 8;
|
|
|
1971 |
info_ptr->num_trans = 0;
|
|
23903
|
1972 |
|
|
|
1973 |
if (png_ptr->palette == NULL)
|
|
|
1974 |
png_error (png_ptr, "Palette is NULL in indexed image");
|
|
2
|
1975 |
}
|
|
|
1976 |
else
|
|
|
1977 |
{
|
|
29913
|
1978 |
if (png_ptr->num_trans != 0)
|
|
2
|
1979 |
{
|
|
29913
|
1980 |
if ((png_ptr->transformations & PNG_EXPAND_tRNS) != 0)
|
|
10576
|
1981 |
info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
|
|
2
|
1982 |
}
|
|
|
1983 |
if (info_ptr->bit_depth < 8)
|
|
|
1984 |
info_ptr->bit_depth = 8;
|
|
10576
|
1985 |
|
|
2
|
1986 |
info_ptr->num_trans = 0;
|
|
|
1987 |
}
|
|
|
1988 |
}
|
|
|
1989 |
#endif
|
|
|
1990 |
|
|
10576
|
1991 |
#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
|
|
|
1992 |
defined(PNG_READ_ALPHA_MODE_SUPPORTED)
|
|
|
1993 |
/* The following is almost certainly wrong unless the background value is in
|
|
|
1994 |
* the screen space!
|
|
|
1995 |
*/
|
|
29913
|
1996 |
if ((png_ptr->transformations & PNG_COMPOSE) != 0)
|
|
2
|
1997 |
info_ptr->background = png_ptr->background;
|
|
|
1998 |
#endif
|
|
|
1999 |
|
|
10576
|
2000 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
|
2001 |
/* The following used to be conditional on PNG_GAMMA (prior to 1.5.4),
|
|
|
2002 |
* however it seems that the code in png_init_read_transformations, which has
|
|
|
2003 |
* been called before this from png_read_update_info->png_read_start_row
|
|
|
2004 |
* sometimes does the gamma transform and cancels the flag.
|
|
29913
|
2005 |
*
|
|
|
2006 |
* TODO: this looks wrong; the info_ptr should end up with a gamma equal to
|
|
|
2007 |
* the screen_gamma value. The following probably results in weirdness if
|
|
|
2008 |
* the info_ptr is used by the app after the rows have been read.
|
|
10576
|
2009 |
*/
|
|
29913
|
2010 |
info_ptr->colorspace.gamma = png_ptr->colorspace.gamma;
|
|
10576
|
2011 |
#endif
|
|
|
2012 |
|
|
|
2013 |
if (info_ptr->bit_depth == 16)
|
|
2
|
2014 |
{
|
|
10576
|
2015 |
# ifdef PNG_READ_16BIT_SUPPORTED
|
|
|
2016 |
# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
|
|
29913
|
2017 |
if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0)
|
|
10576
|
2018 |
info_ptr->bit_depth = 8;
|
|
|
2019 |
# endif
|
|
|
2020 |
|
|
|
2021 |
# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
|
|
29913
|
2022 |
if ((png_ptr->transformations & PNG_16_TO_8) != 0)
|
|
10576
|
2023 |
info_ptr->bit_depth = 8;
|
|
|
2024 |
# endif
|
|
|
2025 |
|
|
|
2026 |
# else
|
|
35296
|
2027 |
/* No 16-bit support: force chopping 16-bit input down to 8, in this case
|
|
10576
|
2028 |
* the app program can chose if both APIs are available by setting the
|
|
|
2029 |
* correct scaling to use.
|
|
|
2030 |
*/
|
|
|
2031 |
# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
|
|
|
2032 |
/* For compatibility with previous versions use the strip method by
|
|
|
2033 |
* default. This code works because if PNG_SCALE_16_TO_8 is already
|
|
|
2034 |
* set the code below will do that in preference to the chop.
|
|
|
2035 |
*/
|
|
|
2036 |
png_ptr->transformations |= PNG_16_TO_8;
|
|
|
2037 |
info_ptr->bit_depth = 8;
|
|
|
2038 |
# else
|
|
|
2039 |
|
|
29913
|
2040 |
# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
|
|
10576
|
2041 |
png_ptr->transformations |= PNG_SCALE_16_TO_8;
|
|
|
2042 |
info_ptr->bit_depth = 8;
|
|
|
2043 |
# else
|
|
|
2044 |
|
|
|
2045 |
CONFIGURATION ERROR: you must enable at least one 16 to 8 method
|
|
|
2046 |
# endif
|
|
|
2047 |
# endif
|
|
29913
|
2048 |
#endif /* !READ_16BIT */
|
|
2
|
2049 |
}
|
|
10576
|
2050 |
|
|
|
2051 |
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
|
29913
|
2052 |
if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
|
|
|
2053 |
info_ptr->color_type = (png_byte)(info_ptr->color_type |
|
|
|
2054 |
PNG_COLOR_MASK_COLOR);
|
|
2
|
2055 |
#endif
|
|
|
2056 |
|
|
10576
|
2057 |
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
|
29913
|
2058 |
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
|
|
|
2059 |
info_ptr->color_type = (png_byte)(info_ptr->color_type &
|
|
|
2060 |
~PNG_COLOR_MASK_COLOR);
|
|
2
|
2061 |
#endif
|
|
|
2062 |
|
|
10576
|
2063 |
#ifdef PNG_READ_QUANTIZE_SUPPORTED
|
|
29913
|
2064 |
if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
|
|
2
|
2065 |
{
|
|
|
2066 |
if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
|
|
10576
|
2067 |
(info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
|
|
29913
|
2068 |
png_ptr->palette_lookup != 0 && info_ptr->bit_depth == 8)
|
|
2
|
2069 |
{
|
|
|
2070 |
info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
|
|
|
2071 |
}
|
|
|
2072 |
}
|
|
|
2073 |
#endif
|
|
|
2074 |
|
|
10576
|
2075 |
#ifdef PNG_READ_EXPAND_16_SUPPORTED
|
|
29913
|
2076 |
if ((png_ptr->transformations & PNG_EXPAND_16) != 0 &&
|
|
|
2077 |
info_ptr->bit_depth == 8 &&
|
|
|
2078 |
info_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
|
|
10576
|
2079 |
{
|
|
|
2080 |
info_ptr->bit_depth = 16;
|
|
|
2081 |
}
|
|
|
2082 |
#endif
|
|
|
2083 |
|
|
|
2084 |
#ifdef PNG_READ_PACK_SUPPORTED
|
|
29913
|
2085 |
if ((png_ptr->transformations & PNG_PACK) != 0 &&
|
|
|
2086 |
(info_ptr->bit_depth < 8))
|
|
2
|
2087 |
info_ptr->bit_depth = 8;
|
|
|
2088 |
#endif
|
|
|
2089 |
|
|
|
2090 |
if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
|
2091 |
info_ptr->channels = 1;
|
|
10576
|
2092 |
|
|
29913
|
2093 |
else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
|
|
2
|
2094 |
info_ptr->channels = 3;
|
|
10576
|
2095 |
|
|
2
|
2096 |
else
|
|
|
2097 |
info_ptr->channels = 1;
|
|
|
2098 |
|
|
10576
|
2099 |
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
|
|
29913
|
2100 |
if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0)
|
|
10576
|
2101 |
{
|
|
29913
|
2102 |
info_ptr->color_type = (png_byte)(info_ptr->color_type &
|
|
|
2103 |
~PNG_COLOR_MASK_ALPHA);
|
|
10576
|
2104 |
info_ptr->num_trans = 0;
|
|
|
2105 |
}
|
|
2
|
2106 |
#endif
|
|
|
2107 |
|
|
29913
|
2108 |
if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
|
|
2
|
2109 |
info_ptr->channels++;
|
|
|
2110 |
|
|
10576
|
2111 |
#ifdef PNG_READ_FILLER_SUPPORTED
|
|
2
|
2112 |
/* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */
|
|
29913
|
2113 |
if ((png_ptr->transformations & PNG_FILLER) != 0 &&
|
|
|
2114 |
(info_ptr->color_type == PNG_COLOR_TYPE_RGB ||
|
|
|
2115 |
info_ptr->color_type == PNG_COLOR_TYPE_GRAY))
|
|
2
|
2116 |
{
|
|
|
2117 |
info_ptr->channels++;
|
|
10576
|
2118 |
/* If adding a true alpha channel not just filler */
|
|
29913
|
2119 |
if ((png_ptr->transformations & PNG_ADD_ALPHA) != 0)
|
|
10576
|
2120 |
info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
|
|
2
|
2121 |
}
|
|
|
2122 |
#endif
|
|
|
2123 |
|
|
|
2124 |
#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
|
|
|
2125 |
defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
|
|
29913
|
2126 |
if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
|
|
10576
|
2127 |
{
|
|
35296
|
2128 |
if (png_ptr->user_transform_depth != 0)
|
|
2
|
2129 |
info_ptr->bit_depth = png_ptr->user_transform_depth;
|
|
10576
|
2130 |
|
|
35296
|
2131 |
if (png_ptr->user_transform_channels != 0)
|
|
2
|
2132 |
info_ptr->channels = png_ptr->user_transform_channels;
|
|
10576
|
2133 |
}
|
|
2
|
2134 |
#endif
|
|
|
2135 |
|
|
|
2136 |
info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
|
|
10576
|
2137 |
info_ptr->bit_depth);
|
|
|
2138 |
|
|
|
2139 |
info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
|
|
|
2140 |
|
|
|
2141 |
/* Adding in 1.5.4: cache the above value in png_struct so that we can later
|
|
|
2142 |
* check in png_rowbytes that the user buffer won't get overwritten. Note
|
|
|
2143 |
* that the field is not always set - if png_read_update_info isn't called
|
|
|
2144 |
* the application has to either not do any transforms or get the calculation
|
|
|
2145 |
* right itself.
|
|
|
2146 |
*/
|
|
|
2147 |
png_ptr->info_rowbytes = info_ptr->rowbytes;
|
|
|
2148 |
|
|
|
2149 |
#ifndef PNG_READ_EXPAND_SUPPORTED
|
|
29913
|
2150 |
if (png_ptr != NULL)
|
|
2
|
2151 |
return;
|
|
|
2152 |
#endif
|
|
|
2153 |
}
|
|
|
2154 |
|
|
10576
|
2155 |
#ifdef PNG_READ_PACK_SUPPORTED
|
|
2
|
2156 |
/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
|
|
|
2157 |
* without changing the actual values. Thus, if you had a row with
|
|
|
2158 |
* a bit depth of 1, you would end up with bytes that only contained
|
|
|
2159 |
* the numbers 0 or 1. If you would rather they contain 0 and 255, use
|
|
|
2160 |
* png_do_shift() after this.
|
|
|
2161 |
*/
|
|
29913
|
2162 |
static void
|
|
2
|
2163 |
png_do_unpack(png_row_infop row_info, png_bytep row)
|
|
|
2164 |
{
|
|
10576
|
2165 |
png_debug(1, "in png_do_unpack");
|
|
|
2166 |
|
|
2
|
2167 |
if (row_info->bit_depth < 8)
|
|
|
2168 |
{
|
|
|
2169 |
png_uint_32 i;
|
|
|
2170 |
png_uint_32 row_width=row_info->width;
|
|
|
2171 |
|
|
|
2172 |
switch (row_info->bit_depth)
|
|
|
2173 |
{
|
|
|
2174 |
case 1:
|
|
|
2175 |
{
|
|
|
2176 |
png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
|
|
|
2177 |
png_bytep dp = row + (png_size_t)row_width - 1;
|
|
|
2178 |
png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);
|
|
|
2179 |
for (i = 0; i < row_width; i++)
|
|
|
2180 |
{
|
|
|
2181 |
*dp = (png_byte)((*sp >> shift) & 0x01);
|
|
10576
|
2182 |
|
|
2
|
2183 |
if (shift == 7)
|
|
|
2184 |
{
|
|
|
2185 |
shift = 0;
|
|
|
2186 |
sp--;
|
|
|
2187 |
}
|
|
10576
|
2188 |
|
|
2
|
2189 |
else
|
|
|
2190 |
shift++;
|
|
|
2191 |
|
|
|
2192 |
dp--;
|
|
|
2193 |
}
|
|
|
2194 |
break;
|
|
|
2195 |
}
|
|
10576
|
2196 |
|
|
2
|
2197 |
case 2:
|
|
|
2198 |
{
|
|
|
2199 |
|
|
|
2200 |
png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
|
|
|
2201 |
png_bytep dp = row + (png_size_t)row_width - 1;
|
|
|
2202 |
png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
|
|
|
2203 |
for (i = 0; i < row_width; i++)
|
|
|
2204 |
{
|
|
|
2205 |
*dp = (png_byte)((*sp >> shift) & 0x03);
|
|
10576
|
2206 |
|
|
2
|
2207 |
if (shift == 6)
|
|
|
2208 |
{
|
|
|
2209 |
shift = 0;
|
|
|
2210 |
sp--;
|
|
|
2211 |
}
|
|
10576
|
2212 |
|
|
2
|
2213 |
else
|
|
|
2214 |
shift += 2;
|
|
|
2215 |
|
|
|
2216 |
dp--;
|
|
|
2217 |
}
|
|
|
2218 |
break;
|
|
|
2219 |
}
|
|
10576
|
2220 |
|
|
2
|
2221 |
case 4:
|
|
|
2222 |
{
|
|
|
2223 |
png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
|
|
|
2224 |
png_bytep dp = row + (png_size_t)row_width - 1;
|
|
|
2225 |
png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
|
|
|
2226 |
for (i = 0; i < row_width; i++)
|
|
|
2227 |
{
|
|
|
2228 |
*dp = (png_byte)((*sp >> shift) & 0x0f);
|
|
10576
|
2229 |
|
|
2
|
2230 |
if (shift == 4)
|
|
|
2231 |
{
|
|
|
2232 |
shift = 0;
|
|
|
2233 |
sp--;
|
|
|
2234 |
}
|
|
10576
|
2235 |
|
|
2
|
2236 |
else
|
|
|
2237 |
shift = 4;
|
|
|
2238 |
|
|
|
2239 |
dp--;
|
|
|
2240 |
}
|
|
|
2241 |
break;
|
|
|
2242 |
}
|
|
10576
|
2243 |
|
|
|
2244 |
default:
|
|
|
2245 |
break;
|
|
2
|
2246 |
}
|
|
|
2247 |
row_info->bit_depth = 8;
|
|
|
2248 |
row_info->pixel_depth = (png_byte)(8 * row_info->channels);
|
|
|
2249 |
row_info->rowbytes = row_width * row_info->channels;
|
|
|
2250 |
}
|
|
|
2251 |
}
|
|
|
2252 |
#endif
|
|
|
2253 |
|
|
10576
|
2254 |
#ifdef PNG_READ_SHIFT_SUPPORTED
|
|
2
|
2255 |
/* Reverse the effects of png_do_shift. This routine merely shifts the
|
|
|
2256 |
* pixels back to their significant bits values. Thus, if you have
|
|
|
2257 |
* a row of bit depth 8, but only 5 are significant, this will shift
|
|
|
2258 |
* the values back to 0 through 31.
|
|
|
2259 |
*/
|
|
29913
|
2260 |
static void
|
|
10576
|
2261 |
png_do_unshift(png_row_infop row_info, png_bytep row,
|
|
|
2262 |
png_const_color_8p sig_bits)
|
|
2
|
2263 |
{
|
|
29913
|
2264 |
int color_type;
|
|
|
2265 |
|
|
10576
|
2266 |
png_debug(1, "in png_do_unshift");
|
|
|
2267 |
|
|
29913
|
2268 |
/* The palette case has already been handled in the _init routine. */
|
|
|
2269 |
color_type = row_info->color_type;
|
|
|
2270 |
|
|
|
2271 |
if (color_type != PNG_COLOR_TYPE_PALETTE)
|
|
2
|
2272 |
{
|
|
|
2273 |
int shift[4];
|
|
|
2274 |
int channels = 0;
|
|
29913
|
2275 |
int bit_depth = row_info->bit_depth;
|
|
|
2276 |
|
|
|
2277 |
if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
|
|
2
|
2278 |
{
|
|
29913
|
2279 |
shift[channels++] = bit_depth - sig_bits->red;
|
|
|
2280 |
shift[channels++] = bit_depth - sig_bits->green;
|
|
|
2281 |
shift[channels++] = bit_depth - sig_bits->blue;
|
|
2
|
2282 |
}
|
|
10576
|
2283 |
|
|
2
|
2284 |
else
|
|
|
2285 |
{
|
|
29913
|
2286 |
shift[channels++] = bit_depth - sig_bits->gray;
|
|
2
|
2287 |
}
|
|
10576
|
2288 |
|
|
29913
|
2289 |
if ((color_type & PNG_COLOR_MASK_ALPHA) != 0)
|
|
2
|
2290 |
{
|
|
29913
|
2291 |
shift[channels++] = bit_depth - sig_bits->alpha;
|
|
2
|
2292 |
}
|
|
|
2293 |
|
|
|
2294 |
{
|
|
29913
|
2295 |
int c, have_shift;
|
|
|
2296 |
|
|
|
2297 |
for (c = have_shift = 0; c < channels; ++c)
|
|
|
2298 |
{
|
|
|
2299 |
/* A shift of more than the bit depth is an error condition but it
|
|
|
2300 |
* gets ignored here.
|
|
|
2301 |
*/
|
|
|
2302 |
if (shift[c] <= 0 || shift[c] >= bit_depth)
|
|
|
2303 |
shift[c] = 0;
|
|
|
2304 |
|
|
|
2305 |
else
|
|
|
2306 |
have_shift = 1;
|
|
|
2307 |
}
|
|
|
2308 |
|
|
|
2309 |
if (have_shift == 0)
|
|
|
2310 |
return;
|
|
2
|
2311 |
}
|
|
|
2312 |
|
|
29913
|
2313 |
switch (bit_depth)
|
|
2
|
2314 |
{
|
|
10576
|
2315 |
default:
|
|
29913
|
2316 |
/* Must be 1bpp gray: should not be here! */
|
|
|
2317 |
/* NOTREACHED */
|
|
10576
|
2318 |
break;
|
|
|
2319 |
|
|
2
|
2320 |
case 2:
|
|
29913
|
2321 |
/* Must be 2bpp gray */
|
|
|
2322 |
/* assert(channels == 1 && shift[0] == 1) */
|
|
2
|
2323 |
{
|
|
29913
|
2324 |
png_bytep bp = row;
|
|
|
2325 |
png_bytep bp_end = bp + row_info->rowbytes;
|
|
|
2326 |
|
|
|
2327 |
while (bp < bp_end)
|
|
2
|
2328 |
{
|
|
29913
|
2329 |
int b = (*bp >> 1) & 0x55;
|
|
|
2330 |
*bp++ = (png_byte)b;
|
|
2
|
2331 |
}
|
|
|
2332 |
break;
|
|
|
2333 |
}
|
|
10576
|
2334 |
|
|
2
|
2335 |
case 4:
|
|
29913
|
2336 |
/* Must be 4bpp gray */
|
|
|
2337 |
/* assert(channels == 1) */
|
|
2
|
2338 |
{
|
|
|
2339 |
png_bytep bp = row;
|
|
29913
|
2340 |
png_bytep bp_end = bp + row_info->rowbytes;
|
|
|
2341 |
int gray_shift = shift[0];
|
|
|
2342 |
int mask = 0xf >> gray_shift;
|
|
|
2343 |
|
|
|
2344 |
mask |= mask << 4;
|
|
|
2345 |
|
|
|
2346 |
while (bp < bp_end)
|
|
2
|
2347 |
{
|
|
29913
|
2348 |
int b = (*bp >> gray_shift) & mask;
|
|
|
2349 |
*bp++ = (png_byte)b;
|
|
2
|
2350 |
}
|
|
|
2351 |
break;
|
|
|
2352 |
}
|
|
10576
|
2353 |
|
|
2
|
2354 |
case 8:
|
|
29913
|
2355 |
/* Single byte components, G, GA, RGB, RGBA */
|
|
2
|
2356 |
{
|
|
|
2357 |
png_bytep bp = row;
|
|
29913
|
2358 |
png_bytep bp_end = bp + row_info->rowbytes;
|
|
|
2359 |
int channel = 0;
|
|
|
2360 |
|
|
|
2361 |
while (bp < bp_end)
|
|
2
|
2362 |
{
|
|
29913
|
2363 |
int b = *bp >> shift[channel];
|
|
|
2364 |
if (++channel >= channels)
|
|
|
2365 |
channel = 0;
|
|
|
2366 |
*bp++ = (png_byte)b;
|
|
2
|
2367 |
}
|
|
|
2368 |
break;
|
|
|
2369 |
}
|
|
10576
|
2370 |
|
|
|
2371 |
#ifdef PNG_READ_16BIT_SUPPORTED
|
|
2
|
2372 |
case 16:
|
|
29913
|
2373 |
/* Double byte components, G, GA, RGB, RGBA */
|
|
2
|
2374 |
{
|
|
|
2375 |
png_bytep bp = row;
|
|
29913
|
2376 |
png_bytep bp_end = bp + row_info->rowbytes;
|
|
|
2377 |
int channel = 0;
|
|
|
2378 |
|
|
|
2379 |
while (bp < bp_end)
|
|
2
|
2380 |
{
|
|
29913
|
2381 |
int value = (bp[0] << 8) + bp[1];
|
|
|
2382 |
|
|
|
2383 |
value >>= shift[channel];
|
|
|
2384 |
if (++channel >= channels)
|
|
|
2385 |
channel = 0;
|
|
2
|
2386 |
*bp++ = (png_byte)(value >> 8);
|
|
35296
|
2387 |
*bp++ = (png_byte)value;
|
|
2
|
2388 |
}
|
|
|
2389 |
break;
|
|
|
2390 |
}
|
|
10576
|
2391 |
#endif
|
|
2
|
2392 |
}
|
|
|
2393 |
}
|
|
|
2394 |
}
|
|
|
2395 |
#endif
|
|
|
2396 |
|
|
10576
|
2397 |
#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
|
|
|
2398 |
/* Scale rows of bit depth 16 down to 8 accurately */
|
|
29913
|
2399 |
static void
|
|
10576
|
2400 |
png_do_scale_16_to_8(png_row_infop row_info, png_bytep row)
|
|
2
|
2401 |
{
|
|
10576
|
2402 |
png_debug(1, "in png_do_scale_16_to_8");
|
|
|
2403 |
|
|
2
|
2404 |
if (row_info->bit_depth == 16)
|
|
|
2405 |
{
|
|
10576
|
2406 |
png_bytep sp = row; /* source */
|
|
29913
|
2407 |
png_bytep dp = row; /* destination */
|
|
10576
|
2408 |
png_bytep ep = sp + row_info->rowbytes; /* end+1 */
|
|
|
2409 |
|
|
|
2410 |
while (sp < ep)
|
|
2
|
2411 |
{
|
|
35296
|
2412 |
/* The input is an array of 16-bit components, these must be scaled to
|
|
|
2413 |
* 8 bits each. For a 16-bit value V the required value (from the PNG
|
|
10576
|
2414 |
* specification) is:
|
|
|
2415 |
*
|
|
|
2416 |
* (V * 255) / 65535
|
|
|
2417 |
*
|
|
|
2418 |
* This reduces to round(V / 257), or floor((V + 128.5)/257)
|
|
|
2419 |
*
|
|
|
2420 |
* Represent V as the two byte value vhi.vlo. Make a guess that the
|
|
|
2421 |
* result is the top byte of V, vhi, then the correction to this value
|
|
|
2422 |
* is:
|
|
|
2423 |
*
|
|
|
2424 |
* error = floor(((V-vhi.vhi) + 128.5) / 257)
|
|
|
2425 |
* = floor(((vlo-vhi) + 128.5) / 257)
|
|
|
2426 |
*
|
|
|
2427 |
* This can be approximated using integer arithmetic (and a signed
|
|
|
2428 |
* shift):
|
|
|
2429 |
*
|
|
|
2430 |
* error = (vlo-vhi+128) >> 8;
|
|
|
2431 |
*
|
|
|
2432 |
* The approximate differs from the exact answer only when (vlo-vhi) is
|
|
|
2433 |
* 128; it then gives a correction of +1 when the exact correction is
|
|
35296
|
2434 |
* 0. This gives 128 errors. The exact answer (correct for all 16-bit
|
|
10576
|
2435 |
* input values) is:
|
|
|
2436 |
*
|
|
|
2437 |
* error = (vlo-vhi+128)*65535 >> 24;
|
|
|
2438 |
*
|
|
|
2439 |
* An alternative arithmetic calculation which also gives no errors is:
|
|
|
2440 |
*
|
|
|
2441 |
* (V * 255 + 32895) >> 16
|
|
|
2442 |
*/
|
|
|
2443 |
|
|
|
2444 |
png_int_32 tmp = *sp++; /* must be signed! */
|
|
|
2445 |
tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24;
|
|
|
2446 |
*dp++ = (png_byte)tmp;
|
|
2
|
2447 |
}
|
|
10576
|
2448 |
|
|
2
|
2449 |
row_info->bit_depth = 8;
|
|
|
2450 |
row_info->pixel_depth = (png_byte)(8 * row_info->channels);
|
|
|
2451 |
row_info->rowbytes = row_info->width * row_info->channels;
|
|
|
2452 |
}
|
|
|
2453 |
}
|
|
|
2454 |
#endif
|
|
|
2455 |
|
|
10576
|
2456 |
#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
|
|
29913
|
2457 |
static void
|
|
10576
|
2458 |
/* Simply discard the low byte. This was the default behavior prior
|
|
|
2459 |
* to libpng-1.5.4.
|
|
|
2460 |
*/
|
|
|
2461 |
png_do_chop(png_row_infop row_info, png_bytep row)
|
|
|
2462 |
{
|
|
|
2463 |
png_debug(1, "in png_do_chop");
|
|
|
2464 |
|
|
|
2465 |
if (row_info->bit_depth == 16)
|
|
|
2466 |
{
|
|
|
2467 |
png_bytep sp = row; /* source */
|
|
29913
|
2468 |
png_bytep dp = row; /* destination */
|
|
10576
|
2469 |
png_bytep ep = sp + row_info->rowbytes; /* end+1 */
|
|
|
2470 |
|
|
|
2471 |
while (sp < ep)
|
|
|
2472 |
{
|
|
|
2473 |
*dp++ = *sp;
|
|
|
2474 |
sp += 2; /* skip low byte */
|
|
|
2475 |
}
|
|
|
2476 |
|
|
|
2477 |
row_info->bit_depth = 8;
|
|
|
2478 |
row_info->pixel_depth = (png_byte)(8 * row_info->channels);
|
|
|
2479 |
row_info->rowbytes = row_info->width * row_info->channels;
|
|
|
2480 |
}
|
|
|
2481 |
}
|
|
|
2482 |
#endif
|
|
|
2483 |
|
|
|
2484 |
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
|
|
29913
|
2485 |
static void
|
|
2
|
2486 |
png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
|
|
|
2487 |
{
|
|
10576
|
2488 |
png_debug(1, "in png_do_read_swap_alpha");
|
|
|
2489 |
|
|
2
|
2490 |
{
|
|
|
2491 |
png_uint_32 row_width = row_info->width;
|
|
|
2492 |
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
|
|
2493 |
{
|
|
|
2494 |
/* This converts from RGBA to ARGB */
|
|
|
2495 |
if (row_info->bit_depth == 8)
|
|
|
2496 |
{
|
|
|
2497 |
png_bytep sp = row + row_info->rowbytes;
|
|
|
2498 |
png_bytep dp = sp;
|
|
|
2499 |
png_byte save;
|
|
|
2500 |
png_uint_32 i;
|
|
|
2501 |
|
|
|
2502 |
for (i = 0; i < row_width; i++)
|
|
|
2503 |
{
|
|
|
2504 |
save = *(--sp);
|
|
|
2505 |
*(--dp) = *(--sp);
|
|
|
2506 |
*(--dp) = *(--sp);
|
|
|
2507 |
*(--dp) = *(--sp);
|
|
|
2508 |
*(--dp) = save;
|
|
|
2509 |
}
|
|
|
2510 |
}
|
|
10576
|
2511 |
|
|
|
2512 |
#ifdef PNG_READ_16BIT_SUPPORTED
|
|
2
|
2513 |
/* This converts from RRGGBBAA to AARRGGBB */
|
|
|
2514 |
else
|
|
|
2515 |
{
|
|
|
2516 |
png_bytep sp = row + row_info->rowbytes;
|
|
|
2517 |
png_bytep dp = sp;
|
|
|
2518 |
png_byte save[2];
|
|
|
2519 |
png_uint_32 i;
|
|
|
2520 |
|
|
|
2521 |
for (i = 0; i < row_width; i++)
|
|
|
2522 |
{
|
|
|
2523 |
save[0] = *(--sp);
|
|
|
2524 |
save[1] = *(--sp);
|
|
|
2525 |
*(--dp) = *(--sp);
|
|
|
2526 |
*(--dp) = *(--sp);
|
|
|
2527 |
*(--dp) = *(--sp);
|
|
|
2528 |
*(--dp) = *(--sp);
|
|
|
2529 |
*(--dp) = *(--sp);
|
|
|
2530 |
*(--dp) = *(--sp);
|
|
|
2531 |
*(--dp) = save[0];
|
|
|
2532 |
*(--dp) = save[1];
|
|
|
2533 |
}
|
|
|
2534 |
}
|
|
10576
|
2535 |
#endif
|
|
2
|
2536 |
}
|
|
10576
|
2537 |
|
|
2
|
2538 |
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
|
|
2539 |
{
|
|
|
2540 |
/* This converts from GA to AG */
|
|
|
2541 |
if (row_info->bit_depth == 8)
|
|
|
2542 |
{
|
|
|
2543 |
png_bytep sp = row + row_info->rowbytes;
|
|
|
2544 |
png_bytep dp = sp;
|
|
|
2545 |
png_byte save;
|
|
|
2546 |
png_uint_32 i;
|
|
|
2547 |
|
|
|
2548 |
for (i = 0; i < row_width; i++)
|
|
|
2549 |
{
|
|
|
2550 |
save = *(--sp);
|
|
|
2551 |
*(--dp) = *(--sp);
|
|
|
2552 |
*(--dp) = save;
|
|
|
2553 |
}
|
|
|
2554 |
}
|
|
10576
|
2555 |
|
|
|
2556 |
#ifdef PNG_READ_16BIT_SUPPORTED
|
|
2
|
2557 |
/* This converts from GGAA to AAGG */
|
|
|
2558 |
else
|
|
|
2559 |
{
|
|
|
2560 |
png_bytep sp = row + row_info->rowbytes;
|
|
|
2561 |
png_bytep dp = sp;
|
|
|
2562 |
png_byte save[2];
|
|
|
2563 |
png_uint_32 i;
|
|
|
2564 |
|
|
|
2565 |
for (i = 0; i < row_width; i++)
|
|
|
2566 |
{
|
|
|
2567 |
save[0] = *(--sp);
|
|
|
2568 |
save[1] = *(--sp);
|
|
|
2569 |
*(--dp) = *(--sp);
|
|
|
2570 |
*(--dp) = *(--sp);
|
|
|
2571 |
*(--dp) = save[0];
|
|
|
2572 |
*(--dp) = save[1];
|
|
|
2573 |
}
|
|
|
2574 |
}
|
|
10576
|
2575 |
#endif
|
|
2
|
2576 |
}
|
|
|
2577 |
}
|
|
|
2578 |
}
|
|
|
2579 |
#endif
|
|
|
2580 |
|
|
10576
|
2581 |
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
|
|
29913
|
2582 |
static void
|
|
2
|
2583 |
png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
|
|
|
2584 |
{
|
|
10576
|
2585 |
png_uint_32 row_width;
|
|
|
2586 |
png_debug(1, "in png_do_read_invert_alpha");
|
|
|
2587 |
|
|
|
2588 |
row_width = row_info->width;
|
|
|
2589 |
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
|
2
|
2590 |
{
|
|
10576
|
2591 |
if (row_info->bit_depth == 8)
|
|
2
|
2592 |
{
|
|
|
2593 |
/* This inverts the alpha channel in RGBA */
|
|
10576
|
2594 |
png_bytep sp = row + row_info->rowbytes;
|
|
|
2595 |
png_bytep dp = sp;
|
|
|
2596 |
png_uint_32 i;
|
|
|
2597 |
|
|
|
2598 |
for (i = 0; i < row_width; i++)
|
|
2
|
2599 |
{
|
|
10576
|
2600 |
*(--dp) = (png_byte)(255 - *(--sp));
|
|
|
2601 |
|
|
|
2602 |
/* This does nothing:
|
|
|
2603 |
*(--dp) = *(--sp);
|
|
|
2604 |
*(--dp) = *(--sp);
|
|
|
2605 |
*(--dp) = *(--sp);
|
|
|
2606 |
We can replace it with:
|
|
2
|
2607 |
*/
|
|
10576
|
2608 |
sp-=3;
|
|
|
2609 |
dp=sp;
|
|
2
|
2610 |
}
|
|
|
2611 |
}
|
|
10576
|
2612 |
|
|
|
2613 |
#ifdef PNG_READ_16BIT_SUPPORTED
|
|
|
2614 |
/* This inverts the alpha channel in RRGGBBAA */
|
|
|
2615 |
else
|
|
|
2616 |
{
|
|
|
2617 |
png_bytep sp = row + row_info->rowbytes;
|
|
|
2618 |
png_bytep dp = sp;
|
|
|
2619 |
png_uint_32 i;
|
|
|
2620 |
|
|
|
2621 |
for (i = 0; i < row_width; i++)
|
|
|
2622 |
{
|
|
|
2623 |
*(--dp) = (png_byte)(255 - *(--sp));
|
|
|
2624 |
*(--dp) = (png_byte)(255 - *(--sp));
|
|
|
2625 |
|
|
|
2626 |
/* This does nothing:
|
|
|
2627 |
*(--dp) = *(--sp);
|
|
|
2628 |
*(--dp) = *(--sp);
|
|
|
2629 |
*(--dp) = *(--sp);
|
|
|
2630 |
*(--dp) = *(--sp);
|
|
|
2631 |
*(--dp) = *(--sp);
|
|
|
2632 |
*(--dp) = *(--sp);
|
|
|
2633 |
We can replace it with:
|
|
|
2634 |
*/
|
|
|
2635 |
sp-=6;
|
|
|
2636 |
dp=sp;
|
|
|
2637 |
}
|
|
|
2638 |
}
|
|
|
2639 |
#endif
|
|
|
2640 |
}
|
|
|
2641 |
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
|
|
2642 |
{
|
|
|
2643 |
if (row_info->bit_depth == 8)
|
|
2
|
2644 |
{
|
|
|
2645 |
/* This inverts the alpha channel in GA */
|
|
10576
|
2646 |
png_bytep sp = row + row_info->rowbytes;
|
|
|
2647 |
png_bytep dp = sp;
|
|
|
2648 |
png_uint_32 i;
|
|
|
2649 |
|
|
|
2650 |
for (i = 0; i < row_width; i++)
|
|
2
|
2651 |
{
|
|
10576
|
2652 |
*(--dp) = (png_byte)(255 - *(--sp));
|
|
|
2653 |
*(--dp) = *(--sp);
|
|
2
|
2654 |
}
|
|
|
2655 |
}
|
|
10576
|
2656 |
|
|
|
2657 |
#ifdef PNG_READ_16BIT_SUPPORTED
|
|
|
2658 |
else
|
|
|
2659 |
{
|
|
|
2660 |
/* This inverts the alpha channel in GGAA */
|
|
|
2661 |
png_bytep sp = row + row_info->rowbytes;
|
|
|
2662 |
png_bytep dp = sp;
|
|
|
2663 |
png_uint_32 i;
|
|
|
2664 |
|
|
|
2665 |
for (i = 0; i < row_width; i++)
|
|
|
2666 |
{
|
|
|
2667 |
*(--dp) = (png_byte)(255 - *(--sp));
|
|
|
2668 |
*(--dp) = (png_byte)(255 - *(--sp));
|
|
|
2669 |
/*
|
|
|
2670 |
*(--dp) = *(--sp);
|
|
|
2671 |
*(--dp) = *(--sp);
|
|
|
2672 |
*/
|
|
|
2673 |
sp-=2;
|
|
|
2674 |
dp=sp;
|
|
|
2675 |
}
|
|
|
2676 |
}
|
|
|
2677 |
#endif
|
|
2
|
2678 |
}
|
|
|
2679 |
}
|
|
|
2680 |
#endif
|
|
|
2681 |
|
|
10576
|
2682 |
#ifdef PNG_READ_FILLER_SUPPORTED
|
|
2
|
2683 |
/* Add filler channel if we have RGB color */
|
|
29913
|
2684 |
static void
|
|
2
|
2685 |
png_do_read_filler(png_row_infop row_info, png_bytep row,
|
|
10576
|
2686 |
png_uint_32 filler, png_uint_32 flags)
|
|
2
|
2687 |
{
|
|
|
2688 |
png_uint_32 i;
|
|
|
2689 |
png_uint_32 row_width = row_info->width;
|
|
|
2690 |
|
|
10576
|
2691 |
#ifdef PNG_READ_16BIT_SUPPORTED
|
|
35296
|
2692 |
png_byte hi_filler = (png_byte)(filler>>8);
|
|
10576
|
2693 |
#endif
|
|
35296
|
2694 |
png_byte lo_filler = (png_byte)filler;
|
|
2
|
2695 |
|
|
10576
|
2696 |
png_debug(1, "in png_do_read_filler");
|
|
|
2697 |
|
|
2
|
2698 |
if (
|
|
|
2699 |
row_info->color_type == PNG_COLOR_TYPE_GRAY)
|
|
|
2700 |
{
|
|
10576
|
2701 |
if (row_info->bit_depth == 8)
|
|
2
|
2702 |
{
|
|
29913
|
2703 |
if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
|
|
2
|
2704 |
{
|
|
10576
|
2705 |
/* This changes the data from G to GX */
|
|
2
|
2706 |
png_bytep sp = row + (png_size_t)row_width;
|
|
|
2707 |
png_bytep dp = sp + (png_size_t)row_width;
|
|
|
2708 |
for (i = 1; i < row_width; i++)
|
|
|
2709 |
{
|
|
|
2710 |
*(--dp) = lo_filler;
|
|
|
2711 |
*(--dp) = *(--sp);
|
|
|
2712 |
}
|
|
|
2713 |
*(--dp) = lo_filler;
|
|
|
2714 |
row_info->channels = 2;
|
|
|
2715 |
row_info->pixel_depth = 16;
|
|
|
2716 |
row_info->rowbytes = row_width * 2;
|
|
|
2717 |
}
|
|
10576
|
2718 |
|
|
2
|
2719 |
else
|
|
|
2720 |
{
|
|
10576
|
2721 |
/* This changes the data from G to XG */
|
|
2
|
2722 |
png_bytep sp = row + (png_size_t)row_width;
|
|
|
2723 |
png_bytep dp = sp + (png_size_t)row_width;
|
|
|
2724 |
for (i = 0; i < row_width; i++)
|
|
|
2725 |
{
|
|
|
2726 |
*(--dp) = *(--sp);
|
|
|
2727 |
*(--dp) = lo_filler;
|
|
|
2728 |
}
|
|
|
2729 |
row_info->channels = 2;
|
|
|
2730 |
row_info->pixel_depth = 16;
|
|
|
2731 |
row_info->rowbytes = row_width * 2;
|
|
|
2732 |
}
|
|
|
2733 |
}
|
|
10576
|
2734 |
|
|
|
2735 |
#ifdef PNG_READ_16BIT_SUPPORTED
|
|
|
2736 |
else if (row_info->bit_depth == 16)
|
|
2
|
2737 |
{
|
|
29913
|
2738 |
if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
|
|
2
|
2739 |
{
|
|
10576
|
2740 |
/* This changes the data from GG to GGXX */
|
|
2
|
2741 |
png_bytep sp = row + (png_size_t)row_width * 2;
|
|
|
2742 |
png_bytep dp = sp + (png_size_t)row_width * 2;
|
|
|
2743 |
for (i = 1; i < row_width; i++)
|
|
|
2744 |
{
|
|
35296
|
2745 |
*(--dp) = lo_filler;
|
|
2
|
2746 |
*(--dp) = hi_filler;
|
|
|
2747 |
*(--dp) = *(--sp);
|
|
|
2748 |
*(--dp) = *(--sp);
|
|
|
2749 |
}
|
|
35296
|
2750 |
*(--dp) = lo_filler;
|
|
2
|
2751 |
*(--dp) = hi_filler;
|
|
|
2752 |
row_info->channels = 2;
|
|
|
2753 |
row_info->pixel_depth = 32;
|
|
|
2754 |
row_info->rowbytes = row_width * 4;
|
|
|
2755 |
}
|
|
10576
|
2756 |
|
|
2
|
2757 |
else
|
|
|
2758 |
{
|
|
10576
|
2759 |
/* This changes the data from GG to XXGG */
|
|
2
|
2760 |
png_bytep sp = row + (png_size_t)row_width * 2;
|
|
|
2761 |
png_bytep dp = sp + (png_size_t)row_width * 2;
|
|
|
2762 |
for (i = 0; i < row_width; i++)
|
|
|
2763 |
{
|
|
|
2764 |
*(--dp) = *(--sp);
|
|
|
2765 |
*(--dp) = *(--sp);
|
|
35296
|
2766 |
*(--dp) = lo_filler;
|
|
2
|
2767 |
*(--dp) = hi_filler;
|
|
|
2768 |
}
|
|
|
2769 |
row_info->channels = 2;
|
|
|
2770 |
row_info->pixel_depth = 32;
|
|
|
2771 |
row_info->rowbytes = row_width * 4;
|
|
|
2772 |
}
|
|
|
2773 |
}
|
|
10576
|
2774 |
#endif
|
|
2
|
2775 |
} /* COLOR_TYPE == GRAY */
|
|
|
2776 |
else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
|
|
|
2777 |
{
|
|
10576
|
2778 |
if (row_info->bit_depth == 8)
|
|
2
|
2779 |
{
|
|
29913
|
2780 |
if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
|
|
2
|
2781 |
{
|
|
10576
|
2782 |
/* This changes the data from RGB to RGBX */
|
|
2
|
2783 |
png_bytep sp = row + (png_size_t)row_width * 3;
|
|
|
2784 |
png_bytep dp = sp + (png_size_t)row_width;
|
|
|
2785 |
for (i = 1; i < row_width; i++)
|
|
|
2786 |
{
|
|
|
2787 |
*(--dp) = lo_filler;
|
|
|
2788 |
*(--dp) = *(--sp);
|
|
|
2789 |
*(--dp) = *(--sp);
|
|
|
2790 |
*(--dp) = *(--sp);
|
|
|
2791 |
}
|
|
|
2792 |
*(--dp) = lo_filler;
|
|
|
2793 |
row_info->channels = 4;
|
|
|
2794 |
row_info->pixel_depth = 32;
|
|
|
2795 |
row_info->rowbytes = row_width * 4;
|
|
|
2796 |
}
|
|
10576
|
2797 |
|
|
2
|
2798 |
else
|
|
|
2799 |
{
|
|
10576
|
2800 |
/* This changes the data from RGB to XRGB */
|
|
2
|
2801 |
png_bytep sp = row + (png_size_t)row_width * 3;
|
|
|
2802 |
png_bytep dp = sp + (png_size_t)row_width;
|
|
|
2803 |
for (i = 0; i < row_width; i++)
|
|
|
2804 |
{
|
|
|
2805 |
*(--dp) = *(--sp);
|
|
|
2806 |
*(--dp) = *(--sp);
|
|
|
2807 |
*(--dp) = *(--sp);
|
|
|
2808 |
*(--dp) = lo_filler;
|
|
|
2809 |
}
|
|
|
2810 |
row_info->channels = 4;
|
|
|
2811 |
row_info->pixel_depth = 32;
|
|
|
2812 |
row_info->rowbytes = row_width * 4;
|
|
|
2813 |
}
|
|
|
2814 |
}
|
|
10576
|
2815 |
|
|
|
2816 |
#ifdef PNG_READ_16BIT_SUPPORTED
|
|
|
2817 |
else if (row_info->bit_depth == 16)
|
|
2
|
2818 |
{
|
|
29913
|
2819 |
if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
|
|
2
|
2820 |
{
|
|
10576
|
2821 |
/* This changes the data from RRGGBB to RRGGBBXX */
|
|
2
|
2822 |
png_bytep sp = row + (png_size_t)row_width * 6;
|
|
|
2823 |
png_bytep dp = sp + (png_size_t)row_width * 2;
|
|
|
2824 |
for (i = 1; i < row_width; i++)
|
|
|
2825 |
{
|
|
35296
|
2826 |
*(--dp) = lo_filler;
|
|
2
|
2827 |
*(--dp) = hi_filler;
|
|
|
2828 |
*(--dp) = *(--sp);
|
|
|
2829 |
*(--dp) = *(--sp);
|
|
|
2830 |
*(--dp) = *(--sp);
|
|
|
2831 |
*(--dp) = *(--sp);
|
|
|
2832 |
*(--dp) = *(--sp);
|
|
|
2833 |
*(--dp) = *(--sp);
|
|
|
2834 |
}
|
|
35296
|
2835 |
*(--dp) = lo_filler;
|
|
2
|
2836 |
*(--dp) = hi_filler;
|
|
|
2837 |
row_info->channels = 4;
|
|
|
2838 |
row_info->pixel_depth = 64;
|
|
|
2839 |
row_info->rowbytes = row_width * 8;
|
|
|
2840 |
}
|
|
10576
|
2841 |
|
|
2
|
2842 |
else
|
|
|
2843 |
{
|
|
10576
|
2844 |
/* This changes the data from RRGGBB to XXRRGGBB */
|
|
2
|
2845 |
png_bytep sp = row + (png_size_t)row_width * 6;
|
|
|
2846 |
png_bytep dp = sp + (png_size_t)row_width * 2;
|
|
|
2847 |
for (i = 0; i < row_width; i++)
|
|
|
2848 |
{
|
|
|
2849 |
*(--dp) = *(--sp);
|
|
|
2850 |
*(--dp) = *(--sp);
|
|
|
2851 |
*(--dp) = *(--sp);
|
|
|
2852 |
*(--dp) = *(--sp);
|
|
|
2853 |
*(--dp) = *(--sp);
|
|
|
2854 |
*(--dp) = *(--sp);
|
|
35296
|
2855 |
*(--dp) = lo_filler;
|
|
2
|
2856 |
*(--dp) = hi_filler;
|
|
|
2857 |
}
|
|
10576
|
2858 |
|
|
2
|
2859 |
row_info->channels = 4;
|
|
|
2860 |
row_info->pixel_depth = 64;
|
|
|
2861 |
row_info->rowbytes = row_width * 8;
|
|
|
2862 |
}
|
|
|
2863 |
}
|
|
10576
|
2864 |
#endif
|
|
2
|
2865 |
} /* COLOR_TYPE == RGB */
|
|
|
2866 |
}
|
|
|
2867 |
#endif
|
|
|
2868 |
|
|
10576
|
2869 |
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
|
|
2870 |
/* Expand grayscale files to RGB, with or without alpha */
|
|
29913
|
2871 |
static void
|
|
2
|
2872 |
png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
|
|
|
2873 |
{
|
|
|
2874 |
png_uint_32 i;
|
|
|
2875 |
png_uint_32 row_width = row_info->width;
|
|
|
2876 |
|
|
10576
|
2877 |
png_debug(1, "in png_do_gray_to_rgb");
|
|
|
2878 |
|
|
2
|
2879 |
if (row_info->bit_depth >= 8 &&
|
|
29913
|
2880 |
(row_info->color_type & PNG_COLOR_MASK_COLOR) == 0)
|
|
2
|
2881 |
{
|
|
|
2882 |
if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
|
|
|
2883 |
{
|
|
|
2884 |
if (row_info->bit_depth == 8)
|
|
|
2885 |
{
|
|
10576
|
2886 |
/* This changes G to RGB */
|
|
2
|
2887 |
png_bytep sp = row + (png_size_t)row_width - 1;
|
|
|
2888 |
png_bytep dp = sp + (png_size_t)row_width * 2;
|
|
|
2889 |
for (i = 0; i < row_width; i++)
|
|
|
2890 |
{
|
|
|
2891 |
*(dp--) = *sp;
|
|
|
2892 |
*(dp--) = *sp;
|
|
|
2893 |
*(dp--) = *(sp--);
|
|
|
2894 |
}
|
|
|
2895 |
}
|
|
10576
|
2896 |
|
|
2
|
2897 |
else
|
|
|
2898 |
{
|
|
10576
|
2899 |
/* This changes GG to RRGGBB */
|
|
2
|
2900 |
png_bytep sp = row + (png_size_t)row_width * 2 - 1;
|
|
|
2901 |
png_bytep dp = sp + (png_size_t)row_width * 4;
|
|
|
2902 |
for (i = 0; i < row_width; i++)
|
|
|
2903 |
{
|
|
|
2904 |
*(dp--) = *sp;
|
|
|
2905 |
*(dp--) = *(sp - 1);
|
|
|
2906 |
*(dp--) = *sp;
|
|
|
2907 |
*(dp--) = *(sp - 1);
|
|
|
2908 |
*(dp--) = *(sp--);
|
|
|
2909 |
*(dp--) = *(sp--);
|
|
|
2910 |
}
|
|
|
2911 |
}
|
|
|
2912 |
}
|
|
10576
|
2913 |
|
|
2
|
2914 |
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
|
|
2915 |
{
|
|
|
2916 |
if (row_info->bit_depth == 8)
|
|
|
2917 |
{
|
|
10576
|
2918 |
/* This changes GA to RGBA */
|
|
2
|
2919 |
png_bytep sp = row + (png_size_t)row_width * 2 - 1;
|
|
|
2920 |
png_bytep dp = sp + (png_size_t)row_width * 2;
|
|
|
2921 |
for (i = 0; i < row_width; i++)
|
|
|
2922 |
{
|
|
|
2923 |
*(dp--) = *(sp--);
|
|
|
2924 |
*(dp--) = *sp;
|
|
|
2925 |
*(dp--) = *sp;
|
|
|
2926 |
*(dp--) = *(sp--);
|
|
|
2927 |
}
|
|
|
2928 |
}
|
|
10576
|
2929 |
|
|
2
|
2930 |
else
|
|
|
2931 |
{
|
|
10576
|
2932 |
/* This changes GGAA to RRGGBBAA */
|
|
2
|
2933 |
png_bytep sp = row + (png_size_t)row_width * 4 - 1;
|
|
|
2934 |
png_bytep dp = sp + (png_size_t)row_width * 4;
|
|
|
2935 |
for (i = 0; i < row_width; i++)
|
|
|
2936 |
{
|
|
|
2937 |
*(dp--) = *(sp--);
|
|
|
2938 |
*(dp--) = *(sp--);
|
|
|
2939 |
*(dp--) = *sp;
|
|
|
2940 |
*(dp--) = *(sp - 1);
|
|
|
2941 |
*(dp--) = *sp;
|
|
|
2942 |
*(dp--) = *(sp - 1);
|
|
|
2943 |
*(dp--) = *(sp--);
|
|
|
2944 |
*(dp--) = *(sp--);
|
|
|
2945 |
}
|
|
|
2946 |
}
|
|
|
2947 |
}
|
|
29913
|
2948 |
row_info->channels = (png_byte)(row_info->channels + 2);
|
|
2
|
2949 |
row_info->color_type |= PNG_COLOR_MASK_COLOR;
|
|
|
2950 |
row_info->pixel_depth = (png_byte)(row_info->channels *
|
|
10576
|
2951 |
row_info->bit_depth);
|
|
|
2952 |
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
|
2
|
2953 |
}
|
|
|
2954 |
}
|
|
|
2955 |
#endif
|
|
|
2956 |
|
|
10576
|
2957 |
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
|
|
2958 |
/* Reduce RGB files to grayscale, with or without alpha
|
|
29913
|
2959 |
* using the equation given in Poynton's ColorFAQ of 1998-01-04 at
|
|
|
2960 |
* <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008 but
|
|
|
2961 |
* versions dated 1998 through November 2002 have been archived at
|
|
|
2962 |
* http://web.archive.org/web/20000816232553/http://www.inforamp.net/
|
|
|
2963 |
* ~poynton/notes/colour_and_gamma/ColorFAQ.txt )
|
|
10576
|
2964 |
* Charles Poynton poynton at poynton.com
|
|
2
|
2965 |
*
|
|
|
2966 |
* Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
|
|
|
2967 |
*
|
|
|
2968 |
* which can be expressed with integers as
|
|
|
2969 |
*
|
|
|
2970 |
* Y = (6969 * R + 23434 * G + 2365 * B)/32768
|
|
|
2971 |
*
|
|
29913
|
2972 |
* Poynton's current link (as of January 2003 through July 2011):
|
|
|
2973 |
* <http://www.poynton.com/notes/colour_and_gamma/>
|
|
|
2974 |
* has changed the numbers slightly:
|
|
|
2975 |
*
|
|
|
2976 |
* Y = 0.2126*R + 0.7152*G + 0.0722*B
|
|
|
2977 |
*
|
|
|
2978 |
* which can be expressed with integers as
|
|
|
2979 |
*
|
|
|
2980 |
* Y = (6966 * R + 23436 * G + 2366 * B)/32768
|
|
|
2981 |
*
|
|
|
2982 |
* Historically, however, libpng uses numbers derived from the ITU-R Rec 709
|
|
|
2983 |
* end point chromaticities and the D65 white point. Depending on the
|
|
|
2984 |
* precision used for the D65 white point this produces a variety of different
|
|
|
2985 |
* numbers, however if the four decimal place value used in ITU-R Rec 709 is
|
|
|
2986 |
* used (0.3127,0.3290) the Y calculation would be:
|
|
|
2987 |
*
|
|
|
2988 |
* Y = (6968 * R + 23435 * G + 2366 * B)/32768
|
|
2
|
2989 |
*
|
|
29913
|
2990 |
* While this is correct the rounding results in an overflow for white, because
|
|
|
2991 |
* the sum of the rounded coefficients is 32769, not 32768. Consequently
|
|
|
2992 |
* libpng uses, instead, the closest non-overflowing approximation:
|
|
|
2993 |
*
|
|
|
2994 |
* Y = (6968 * R + 23434 * G + 2366 * B)/32768
|
|
|
2995 |
*
|
|
|
2996 |
* Starting with libpng-1.5.5, if the image being converted has a cHRM chunk
|
|
|
2997 |
* (including an sRGB chunk) then the chromaticities are used to calculate the
|
|
|
2998 |
* coefficients. See the chunk handling in pngrutil.c for more information.
|
|
|
2999 |
*
|
|
|
3000 |
* In all cases the calculation is to be done in a linear colorspace. If no
|
|
|
3001 |
* gamma information is available to correct the encoding of the original RGB
|
|
|
3002 |
* values this results in an implicit assumption that the original PNG RGB
|
|
|
3003 |
* values were linear.
|
|
|
3004 |
*
|
|
|
3005 |
* Other integer coefficents can be used via png_set_rgb_to_gray(). Because
|
|
|
3006 |
* the API takes just red and green coefficients the blue coefficient is
|
|
|
3007 |
* calculated to make the sum 32768. This will result in different rounding
|
|
|
3008 |
* to that used above.
|
|
2
|
3009 |
*/
|
|
29913
|
3010 |
static int
|
|
|
3011 |
png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
|
|
2
|
3012 |
|
|
|
3013 |
{
|
|
|
3014 |
int rgb_error = 0;
|
|
|
3015 |
|
|
10576
|
3016 |
png_debug(1, "in png_do_rgb_to_gray");
|
|
|
3017 |
|
|
29913
|
3018 |
if ((row_info->color_type & PNG_COLOR_MASK_PALETTE) == 0 &&
|
|
|
3019 |
(row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
|
|
2
|
3020 |
{
|
|
29913
|
3021 |
PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
|
|
|
3022 |
PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
|
|
|
3023 |
PNG_CONST png_uint_32 bc = 32768 - rc - gc;
|
|
|
3024 |
PNG_CONST png_uint_32 row_width = row_info->width;
|
|
|
3025 |
PNG_CONST int have_alpha =
|
|
|
3026 |
(row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0;
|
|
|
3027 |
|
|
|
3028 |
if (row_info->bit_depth == 8)
|
|
2
|
3029 |
{
|
|
29913
|
3030 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
|
3031 |
/* Notice that gamma to/from 1 are not necessarily inverses (if
|
|
|
3032 |
* there is an overall gamma correction). Prior to 1.5.5 this code
|
|
|
3033 |
* checked the linearized values for equality; this doesn't match
|
|
|
3034 |
* the documentation, the original values must be checked.
|
|
|
3035 |
*/
|
|
|
3036 |
if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
|
|
2
|
3037 |
{
|
|
29913
|
3038 |
png_bytep sp = row;
|
|
|
3039 |
png_bytep dp = row;
|
|
|
3040 |
png_uint_32 i;
|
|
|
3041 |
|
|
|
3042 |
for (i = 0; i < row_width; i++)
|
|
2
|
3043 |
{
|
|
29913
|
3044 |
png_byte red = *(sp++);
|
|
|
3045 |
png_byte green = *(sp++);
|
|
|
3046 |
png_byte blue = *(sp++);
|
|
|
3047 |
|
|
|
3048 |
if (red != green || red != blue)
|
|
|
3049 |
{
|
|
|
3050 |
red = png_ptr->gamma_to_1[red];
|
|
|
3051 |
green = png_ptr->gamma_to_1[green];
|
|
|
3052 |
blue = png_ptr->gamma_to_1[blue];
|
|
|
3053 |
|
|
|
3054 |
rgb_error |= 1;
|
|
|
3055 |
*(dp++) = png_ptr->gamma_from_1[
|
|
|
3056 |
(rc*red + gc*green + bc*blue + 16384)>>15];
|
|
|
3057 |
}
|
|
|
3058 |
|
|
|
3059 |
else
|
|
2
|
3060 |
{
|
|
29913
|
3061 |
/* If there is no overall correction the table will not be
|
|
|
3062 |
* set.
|
|
|
3063 |
*/
|
|
|
3064 |
if (png_ptr->gamma_table != NULL)
|
|
|
3065 |
red = png_ptr->gamma_table[red];
|
|
|
3066 |
|
|
|
3067 |
*(dp++) = red;
|
|
|
3068 |
}
|
|
|
3069 |
|
|
|
3070 |
if (have_alpha != 0)
|
|
|
3071 |
*(dp++) = *(sp++);
|
|
|
3072 |
}
|
|
|
3073 |
}
|
|
|
3074 |
else
|
|
|
3075 |
#endif
|
|
|
3076 |
{
|
|
|
3077 |
png_bytep sp = row;
|
|
|
3078 |
png_bytep dp = row;
|
|
|
3079 |
png_uint_32 i;
|
|
|
3080 |
|
|
|
3081 |
for (i = 0; i < row_width; i++)
|
|
|
3082 |
{
|
|
|
3083 |
png_byte red = *(sp++);
|
|
|
3084 |
png_byte green = *(sp++);
|
|
|
3085 |
png_byte blue = *(sp++);
|
|
|
3086 |
|
|
|
3087 |
if (red != green || red != blue)
|
|
|
3088 |
{
|
|
|
3089 |
rgb_error |= 1;
|
|
|
3090 |
/* NOTE: this is the historical approach which simply
|
|
|
3091 |
* truncates the results.
|
|
|
3092 |
*/
|
|
|
3093 |
*(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
|
|
|
3094 |
}
|
|
|
3095 |
|
|
|
3096 |
else
|
|
|
3097 |
*(dp++) = red;
|
|
|
3098 |
|
|
|
3099 |
if (have_alpha != 0)
|
|
|
3100 |
*(dp++) = *(sp++);
|
|
|
3101 |
}
|
|
|
3102 |
}
|
|
|
3103 |
}
|
|
|
3104 |
|
|
|
3105 |
else /* RGB bit_depth == 16 */
|
|
|
3106 |
{
|
|
|
3107 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
|
3108 |
if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL)
|
|
|
3109 |
{
|
|
|
3110 |
png_bytep sp = row;
|
|
|
3111 |
png_bytep dp = row;
|
|
|
3112 |
png_uint_32 i;
|
|
|
3113 |
|
|
|
3114 |
for (i = 0; i < row_width; i++)
|
|
|
3115 |
{
|
|
|
3116 |
png_uint_16 red, green, blue, w;
|
|
35296
|
3117 |
png_byte hi,lo;
|
|
|
3118 |
|
|
|
3119 |
hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo));
|
|
|
3120 |
hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo));
|
|
|
3121 |
hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo));
|
|
29913
|
3122 |
|
|
|
3123 |
if (red == green && red == blue)
|
|
|
3124 |
{
|
|
|
3125 |
if (png_ptr->gamma_16_table != NULL)
|
|
|
3126 |
w = png_ptr->gamma_16_table[(red & 0xff)
|
|
|
3127 |
>> png_ptr->gamma_shift][red >> 8];
|
|
10576
|
3128 |
|
|
2
|
3129 |
else
|
|
29913
|
3130 |
w = red;
|
|
2
|
3131 |
}
|
|
29913
|
3132 |
|
|
|
3133 |
else
|
|
2
|
3134 |
{
|
|
35296
|
3135 |
png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red & 0xff)
|
|
29913
|
3136 |
>> png_ptr->gamma_shift][red>>8];
|
|
|
3137 |
png_uint_16 green_1 =
|
|
35296
|
3138 |
png_ptr->gamma_16_to_1[(green & 0xff) >>
|
|
29913
|
3139 |
png_ptr->gamma_shift][green>>8];
|
|
35296
|
3140 |
png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue & 0xff)
|
|
29913
|
3141 |
>> png_ptr->gamma_shift][blue>>8];
|
|
|
3142 |
png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1
|
|
|
3143 |
+ bc*blue_1 + 16384)>>15);
|
|
35296
|
3144 |
w = png_ptr->gamma_16_from_1[(gray16 & 0xff) >>
|
|
29913
|
3145 |
png_ptr->gamma_shift][gray16 >> 8];
|
|
|
3146 |
rgb_error |= 1;
|
|
|
3147 |
}
|
|
|
3148 |
|
|
|
3149 |
*(dp++) = (png_byte)((w>>8) & 0xff);
|
|
|
3150 |
*(dp++) = (png_byte)(w & 0xff);
|
|
|
3151 |
|
|
|
3152 |
if (have_alpha != 0)
|
|
|
3153 |
{
|
|
|
3154 |
*(dp++) = *(sp++);
|
|
|
3155 |
*(dp++) = *(sp++);
|
|
2
|
3156 |
}
|
|
|
3157 |
}
|
|
|
3158 |
}
|
|
29913
|
3159 |
else
|
|
|
3160 |
#endif
|
|
2
|
3161 |
{
|
|
29913
|
3162 |
png_bytep sp = row;
|
|
|
3163 |
png_bytep dp = row;
|
|
|
3164 |
png_uint_32 i;
|
|
|
3165 |
|
|
|
3166 |
for (i = 0; i < row_width; i++)
|
|
2
|
3167 |
{
|
|
29913
|
3168 |
png_uint_16 red, green, blue, gray16;
|
|
35296
|
3169 |
png_byte hi,lo;
|
|
|
3170 |
|
|
|
3171 |
hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo));
|
|
|
3172 |
hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo));
|
|
|
3173 |
hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo));
|
|
29913
|
3174 |
|
|
|
3175 |
if (red != green || red != blue)
|
|
|
3176 |
rgb_error |= 1;
|
|
|
3177 |
|
|
35296
|
3178 |
/* From 1.5.5 in the 16-bit case do the accurate conversion even
|
|
29913
|
3179 |
* in the 'fast' case - this is because this is where the code
|
|
35296
|
3180 |
* ends up when handling linear 16-bit data.
|
|
29913
|
3181 |
*/
|
|
|
3182 |
gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >>
|
|
|
3183 |
15);
|
|
|
3184 |
*(dp++) = (png_byte)((gray16 >> 8) & 0xff);
|
|
|
3185 |
*(dp++) = (png_byte)(gray16 & 0xff);
|
|
|
3186 |
|
|
|
3187 |
if (have_alpha != 0)
|
|
2
|
3188 |
{
|
|
|
3189 |
*(dp++) = *(sp++);
|
|
|
3190 |
*(dp++) = *(sp++);
|
|
|
3191 |
}
|
|
|
3192 |
}
|
|
|
3193 |
}
|
|
|
3194 |
}
|
|
29913
|
3195 |
|
|
|
3196 |
row_info->channels = (png_byte)(row_info->channels - 2);
|
|
10576
|
3197 |
row_info->color_type = (png_byte)(row_info->color_type &
|
|
|
3198 |
~PNG_COLOR_MASK_COLOR);
|
|
2
|
3199 |
row_info->pixel_depth = (png_byte)(row_info->channels *
|
|
10576
|
3200 |
row_info->bit_depth);
|
|
|
3201 |
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
|
2
|
3202 |
}
|
|
|
3203 |
return rgb_error;
|
|
|
3204 |
}
|
|
|
3205 |
#endif
|
|
29913
|
3206 |
|
|
|
3207 |
#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
|
|
|
3208 |
defined(PNG_READ_ALPHA_MODE_SUPPORTED)
|
|
2
|
3209 |
/* Replace any alpha or transparency with the supplied background color.
|
|
|
3210 |
* "background" is already in the screen gamma, while "background_1" is
|
|
|
3211 |
* at a gamma of 1.0. Paletted files have already been taken care of.
|
|
|
3212 |
*/
|
|
29913
|
3213 |
static void
|
|
|
3214 |
png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
|
|
2
|
3215 |
{
|
|
10576
|
3216 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
|
3217 |
png_const_bytep gamma_table = png_ptr->gamma_table;
|
|
|
3218 |
png_const_bytep gamma_from_1 = png_ptr->gamma_from_1;
|
|
|
3219 |
png_const_bytep gamma_to_1 = png_ptr->gamma_to_1;
|
|
|
3220 |
png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table;
|
|
|
3221 |
png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1;
|
|
|
3222 |
png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1;
|
|
|
3223 |
int gamma_shift = png_ptr->gamma_shift;
|
|
29913
|
3224 |
int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0;
|
|
10576
|
3225 |
#endif
|
|
|
3226 |
|
|
|
3227 |
png_bytep sp;
|
|
2
|
3228 |
png_uint_32 i;
|
|
10576
|
3229 |
png_uint_32 row_width = row_info->width;
|
|
2
|
3230 |
int shift;
|
|
|
3231 |
|
|
10576
|
3232 |
png_debug(1, "in png_do_compose");
|
|
|
3233 |
|
|
2
|
3234 |
{
|
|
|
3235 |
switch (row_info->color_type)
|
|
|
3236 |
{
|
|
|
3237 |
case PNG_COLOR_TYPE_GRAY:
|
|
|
3238 |
{
|
|
|
3239 |
switch (row_info->bit_depth)
|
|
|
3240 |
{
|
|
|
3241 |
case 1:
|
|
|
3242 |
{
|
|
|
3243 |
sp = row;
|
|
|
3244 |
shift = 7;
|
|
|
3245 |
for (i = 0; i < row_width; i++)
|
|
|
3246 |
{
|
|
|
3247 |
if ((png_uint_16)((*sp >> shift) & 0x01)
|
|
10576
|
3248 |
== png_ptr->trans_color.gray)
|
|
2
|
3249 |
{
|
|
29913
|
3250 |
unsigned int tmp = *sp & (0x7f7f >> (7 - shift));
|
|
|
3251 |
tmp |= png_ptr->background.gray << shift;
|
|
|
3252 |
*sp = (png_byte)(tmp & 0xff);
|
|
2
|
3253 |
}
|
|
10576
|
3254 |
|
|
29913
|
3255 |
if (shift == 0)
|
|
2
|
3256 |
{
|
|
|
3257 |
shift = 7;
|
|
|
3258 |
sp++;
|
|
|
3259 |
}
|
|
10576
|
3260 |
|
|
2
|
3261 |
else
|
|
|
3262 |
shift--;
|
|
|
3263 |
}
|
|
|
3264 |
break;
|
|
|
3265 |
}
|
|
10576
|
3266 |
|
|
2
|
3267 |
case 2:
|
|
|
3268 |
{
|
|
10576
|
3269 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
2
|
3270 |
if (gamma_table != NULL)
|
|
|
3271 |
{
|
|
|
3272 |
sp = row;
|
|
|
3273 |
shift = 6;
|
|
|
3274 |
for (i = 0; i < row_width; i++)
|
|
|
3275 |
{
|
|
|
3276 |
if ((png_uint_16)((*sp >> shift) & 0x03)
|
|
10576
|
3277 |
== png_ptr->trans_color.gray)
|
|
2
|
3278 |
{
|
|
29913
|
3279 |
unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
|
|
|
3280 |
tmp |= png_ptr->background.gray << shift;
|
|
|
3281 |
*sp = (png_byte)(tmp & 0xff);
|
|
2
|
3282 |
}
|
|
10576
|
3283 |
|
|
2
|
3284 |
else
|
|
|
3285 |
{
|
|
29913
|
3286 |
unsigned int p = (*sp >> shift) & 0x03;
|
|
|
3287 |
unsigned int g = (gamma_table [p | (p << 2) |
|
|
|
3288 |
(p << 4) | (p << 6)] >> 6) & 0x03;
|
|
|
3289 |
unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
|
|
|
3290 |
tmp |= g << shift;
|
|
|
3291 |
*sp = (png_byte)(tmp & 0xff);
|
|
2
|
3292 |
}
|
|
10576
|
3293 |
|
|
29913
|
3294 |
if (shift == 0)
|
|
2
|
3295 |
{
|
|
|
3296 |
shift = 6;
|
|
|
3297 |
sp++;
|
|
|
3298 |
}
|
|
10576
|
3299 |
|
|
2
|
3300 |
else
|
|
|
3301 |
shift -= 2;
|
|
|
3302 |
}
|
|
|
3303 |
}
|
|
10576
|
3304 |
|
|
2
|
3305 |
else
|
|
|
3306 |
#endif
|
|
|
3307 |
{
|
|
|
3308 |
sp = row;
|
|
|
3309 |
shift = 6;
|
|
|
3310 |
for (i = 0; i < row_width; i++)
|
|
|
3311 |
{
|
|
|
3312 |
if ((png_uint_16)((*sp >> shift) & 0x03)
|
|
10576
|
3313 |
== png_ptr->trans_color.gray)
|
|
2
|
3314 |
{
|
|
29913
|
3315 |
unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
|
|
|
3316 |
tmp |= png_ptr->background.gray << shift;
|
|
|
3317 |
*sp = (png_byte)(tmp & 0xff);
|
|
2
|
3318 |
}
|
|
10576
|
3319 |
|
|
29913
|
3320 |
if (shift == 0)
|
|
2
|
3321 |
{
|
|
|
3322 |
shift = 6;
|
|
|
3323 |
sp++;
|
|
|
3324 |
}
|
|
10576
|
3325 |
|
|
2
|
3326 |
else
|
|
|
3327 |
shift -= 2;
|
|
|
3328 |
}
|
|
|
3329 |
}
|
|
|
3330 |
break;
|
|
|
3331 |
}
|
|
10576
|
3332 |
|
|
2
|
3333 |
case 4:
|
|
|
3334 |
{
|
|
10576
|
3335 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
2
|
3336 |
if (gamma_table != NULL)
|
|
|
3337 |
{
|
|
|
3338 |
sp = row;
|
|
|
3339 |
shift = 4;
|
|
|
3340 |
for (i = 0; i < row_width; i++)
|
|
|
3341 |
{
|
|
|
3342 |
if ((png_uint_16)((*sp >> shift) & 0x0f)
|
|
10576
|
3343 |
== png_ptr->trans_color.gray)
|
|
2
|
3344 |
{
|
|
35296
|
3345 |
unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
|
|
29913
|
3346 |
tmp |= png_ptr->background.gray << shift;
|
|
|
3347 |
*sp = (png_byte)(tmp & 0xff);
|
|
2
|
3348 |
}
|
|
10576
|
3349 |
|
|
2
|
3350 |
else
|
|
|
3351 |
{
|
|
29913
|
3352 |
unsigned int p = (*sp >> shift) & 0x0f;
|
|
|
3353 |
unsigned int g = (gamma_table[p | (p << 4)] >> 4) &
|
|
|
3354 |
0x0f;
|
|
35296
|
3355 |
unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
|
|
29913
|
3356 |
tmp |= g << shift;
|
|
|
3357 |
*sp = (png_byte)(tmp & 0xff);
|
|
2
|
3358 |
}
|
|
10576
|
3359 |
|
|
29913
|
3360 |
if (shift == 0)
|
|
2
|
3361 |
{
|
|
|
3362 |
shift = 4;
|
|
|
3363 |
sp++;
|
|
|
3364 |
}
|
|
10576
|
3365 |
|
|
2
|
3366 |
else
|
|
|
3367 |
shift -= 4;
|
|
|
3368 |
}
|
|
|
3369 |
}
|
|
10576
|
3370 |
|
|
2
|
3371 |
else
|
|
|
3372 |
#endif
|
|
|
3373 |
{
|
|
|
3374 |
sp = row;
|
|
|
3375 |
shift = 4;
|
|
|
3376 |
for (i = 0; i < row_width; i++)
|
|
|
3377 |
{
|
|
|
3378 |
if ((png_uint_16)((*sp >> shift) & 0x0f)
|
|
10576
|
3379 |
== png_ptr->trans_color.gray)
|
|
2
|
3380 |
{
|
|
35296
|
3381 |
unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
|
|
29913
|
3382 |
tmp |= png_ptr->background.gray << shift;
|
|
|
3383 |
*sp = (png_byte)(tmp & 0xff);
|
|
2
|
3384 |
}
|
|
10576
|
3385 |
|
|
29913
|
3386 |
if (shift == 0)
|
|
2
|
3387 |
{
|
|
|
3388 |
shift = 4;
|
|
|
3389 |
sp++;
|
|
|
3390 |
}
|
|
10576
|
3391 |
|
|
2
|
3392 |
else
|
|
|
3393 |
shift -= 4;
|
|
|
3394 |
}
|
|
|
3395 |
}
|
|
|
3396 |
break;
|
|
|
3397 |
}
|
|
10576
|
3398 |
|
|
2
|
3399 |
case 8:
|
|
|
3400 |
{
|
|
10576
|
3401 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
2
|
3402 |
if (gamma_table != NULL)
|
|
|
3403 |
{
|
|
|
3404 |
sp = row;
|
|
|
3405 |
for (i = 0; i < row_width; i++, sp++)
|
|
|
3406 |
{
|
|
10576
|
3407 |
if (*sp == png_ptr->trans_color.gray)
|
|
|
3408 |
*sp = (png_byte)png_ptr->background.gray;
|
|
|
3409 |
|
|
2
|
3410 |
else
|
|
|
3411 |
*sp = gamma_table[*sp];
|
|
|
3412 |
}
|
|
|
3413 |
}
|
|
|
3414 |
else
|
|
|
3415 |
#endif
|
|
|
3416 |
{
|
|
|
3417 |
sp = row;
|
|
|
3418 |
for (i = 0; i < row_width; i++, sp++)
|
|
|
3419 |
{
|
|
10576
|
3420 |
if (*sp == png_ptr->trans_color.gray)
|
|
|
3421 |
*sp = (png_byte)png_ptr->background.gray;
|
|
2
|
3422 |
}
|
|
|
3423 |
}
|
|
|
3424 |
break;
|
|
|
3425 |
}
|
|
10576
|
3426 |
|
|
2
|
3427 |
case 16:
|
|
|
3428 |
{
|
|
10576
|
3429 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
2
|
3430 |
if (gamma_16 != NULL)
|
|
|
3431 |
{
|
|
|
3432 |
sp = row;
|
|
|
3433 |
for (i = 0; i < row_width; i++, sp += 2)
|
|
|
3434 |
{
|
|
|
3435 |
png_uint_16 v;
|
|
|
3436 |
|
|
|
3437 |
v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
|
10576
|
3438 |
|
|
|
3439 |
if (v == png_ptr->trans_color.gray)
|
|
2
|
3440 |
{
|
|
10576
|
3441 |
/* Background is already in screen gamma */
|
|
29913
|
3442 |
*sp = (png_byte)((png_ptr->background.gray >> 8)
|
|
|
3443 |
& 0xff);
|
|
|
3444 |
*(sp + 1) = (png_byte)(png_ptr->background.gray
|
|
|
3445 |
& 0xff);
|
|
2
|
3446 |
}
|
|
10576
|
3447 |
|
|
2
|
3448 |
else
|
|
|
3449 |
{
|
|
|
3450 |
v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
|
|
|
3451 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
3452 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
|
3453 |
}
|
|
|
3454 |
}
|
|
|
3455 |
}
|
|
|
3456 |
else
|
|
|
3457 |
#endif
|
|
|
3458 |
{
|
|
|
3459 |
sp = row;
|
|
|
3460 |
for (i = 0; i < row_width; i++, sp += 2)
|
|
|
3461 |
{
|
|
|
3462 |
png_uint_16 v;
|
|
|
3463 |
|
|
|
3464 |
v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
|
10576
|
3465 |
|
|
|
3466 |
if (v == png_ptr->trans_color.gray)
|
|
2
|
3467 |
{
|
|
29913
|
3468 |
*sp = (png_byte)((png_ptr->background.gray >> 8)
|
|
|
3469 |
& 0xff);
|
|
|
3470 |
*(sp + 1) = (png_byte)(png_ptr->background.gray
|
|
|
3471 |
& 0xff);
|
|
2
|
3472 |
}
|
|
|
3473 |
}
|
|
|
3474 |
}
|
|
|
3475 |
break;
|
|
|
3476 |
}
|
|
10576
|
3477 |
|
|
|
3478 |
default:
|
|
|
3479 |
break;
|
|
2
|
3480 |
}
|
|
|
3481 |
break;
|
|
|
3482 |
}
|
|
10576
|
3483 |
|
|
2
|
3484 |
case PNG_COLOR_TYPE_RGB:
|
|
|
3485 |
{
|
|
|
3486 |
if (row_info->bit_depth == 8)
|
|
|
3487 |
{
|
|
10576
|
3488 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
2
|
3489 |
if (gamma_table != NULL)
|
|
|
3490 |
{
|
|
|
3491 |
sp = row;
|
|
|
3492 |
for (i = 0; i < row_width; i++, sp += 3)
|
|
|
3493 |
{
|
|
10576
|
3494 |
if (*sp == png_ptr->trans_color.red &&
|
|
|
3495 |
*(sp + 1) == png_ptr->trans_color.green &&
|
|
|
3496 |
*(sp + 2) == png_ptr->trans_color.blue)
|
|
2
|
3497 |
{
|
|
10576
|
3498 |
*sp = (png_byte)png_ptr->background.red;
|
|
|
3499 |
*(sp + 1) = (png_byte)png_ptr->background.green;
|
|
|
3500 |
*(sp + 2) = (png_byte)png_ptr->background.blue;
|
|
2
|
3501 |
}
|
|
10576
|
3502 |
|
|
2
|
3503 |
else
|
|
|
3504 |
{
|
|
|
3505 |
*sp = gamma_table[*sp];
|
|
|
3506 |
*(sp + 1) = gamma_table[*(sp + 1)];
|
|
|
3507 |
*(sp + 2) = gamma_table[*(sp + 2)];
|
|
|
3508 |
}
|
|
|
3509 |
}
|
|
|
3510 |
}
|
|
|
3511 |
else
|
|
|
3512 |
#endif
|
|
|
3513 |
{
|
|
|
3514 |
sp = row;
|
|
|
3515 |
for (i = 0; i < row_width; i++, sp += 3)
|
|
|
3516 |
{
|
|
10576
|
3517 |
if (*sp == png_ptr->trans_color.red &&
|
|
|
3518 |
*(sp + 1) == png_ptr->trans_color.green &&
|
|
|
3519 |
*(sp + 2) == png_ptr->trans_color.blue)
|
|
2
|
3520 |
{
|
|
10576
|
3521 |
*sp = (png_byte)png_ptr->background.red;
|
|
|
3522 |
*(sp + 1) = (png_byte)png_ptr->background.green;
|
|
|
3523 |
*(sp + 2) = (png_byte)png_ptr->background.blue;
|
|
2
|
3524 |
}
|
|
|
3525 |
}
|
|
|
3526 |
}
|
|
|
3527 |
}
|
|
|
3528 |
else /* if (row_info->bit_depth == 16) */
|
|
|
3529 |
{
|
|
10576
|
3530 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
2
|
3531 |
if (gamma_16 != NULL)
|
|
|
3532 |
{
|
|
|
3533 |
sp = row;
|
|
|
3534 |
for (i = 0; i < row_width; i++, sp += 6)
|
|
|
3535 |
{
|
|
|
3536 |
png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
|
10576
|
3537 |
|
|
|
3538 |
png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
|
|
|
3539 |
+ *(sp + 3));
|
|
|
3540 |
|
|
|
3541 |
png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
|
|
|
3542 |
+ *(sp + 5));
|
|
|
3543 |
|
|
|
3544 |
if (r == png_ptr->trans_color.red &&
|
|
|
3545 |
g == png_ptr->trans_color.green &&
|
|
|
3546 |
b == png_ptr->trans_color.blue)
|
|
2
|
3547 |
{
|
|
10576
|
3548 |
/* Background is already in screen gamma */
|
|
|
3549 |
*sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
|
|
|
3550 |
*(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
|
|
29913
|
3551 |
*(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
|
|
|
3552 |
& 0xff);
|
|
|
3553 |
*(sp + 3) = (png_byte)(png_ptr->background.green
|
|
|
3554 |
& 0xff);
|
|
|
3555 |
*(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
|
|
|
3556 |
& 0xff);
|
|
10576
|
3557 |
*(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
|
|
2
|
3558 |
}
|
|
10576
|
3559 |
|
|
2
|
3560 |
else
|
|
|
3561 |
{
|
|
|
3562 |
png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
|
|
|
3563 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
3564 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
10576
|
3565 |
|
|
2
|
3566 |
v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
|
|
|
3567 |
*(sp + 2) = (png_byte)((v >> 8) & 0xff);
|
|
|
3568 |
*(sp + 3) = (png_byte)(v & 0xff);
|
|
10576
|
3569 |
|
|
2
|
3570 |
v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
|
|
|
3571 |
*(sp + 4) = (png_byte)((v >> 8) & 0xff);
|
|
|
3572 |
*(sp + 5) = (png_byte)(v & 0xff);
|
|
|
3573 |
}
|
|
|
3574 |
}
|
|
|
3575 |
}
|
|
10576
|
3576 |
|
|
|
3577 |
else
|
|
|
3578 |
#endif
|
|
|
3579 |
{
|
|
|
3580 |
sp = row;
|
|
|
3581 |
for (i = 0; i < row_width; i++, sp += 6)
|
|
|
3582 |
{
|
|
|
3583 |
png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
|
|
3584 |
|
|
|
3585 |
png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
|
|
|
3586 |
+ *(sp + 3));
|
|
|
3587 |
|
|
|
3588 |
png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
|
|
|
3589 |
+ *(sp + 5));
|
|
|
3590 |
|
|
|
3591 |
if (r == png_ptr->trans_color.red &&
|
|
|
3592 |
g == png_ptr->trans_color.green &&
|
|
|
3593 |
b == png_ptr->trans_color.blue)
|
|
|
3594 |
{
|
|
|
3595 |
*sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
|
|
|
3596 |
*(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
|
|
29913
|
3597 |
*(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
|
|
|
3598 |
& 0xff);
|
|
|
3599 |
*(sp + 3) = (png_byte)(png_ptr->background.green
|
|
|
3600 |
& 0xff);
|
|
|
3601 |
*(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
|
|
|
3602 |
& 0xff);
|
|
10576
|
3603 |
*(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
|
|
|
3604 |
}
|
|
|
3605 |
}
|
|
|
3606 |
}
|
|
|
3607 |
}
|
|
|
3608 |
break;
|
|
|
3609 |
}
|
|
|
3610 |
|
|
|
3611 |
case PNG_COLOR_TYPE_GRAY_ALPHA:
|
|
|
3612 |
{
|
|
|
3613 |
if (row_info->bit_depth == 8)
|
|
|
3614 |
{
|
|
|
3615 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
|
3616 |
if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
|
|
|
3617 |
gamma_table != NULL)
|
|
|
3618 |
{
|
|
|
3619 |
sp = row;
|
|
|
3620 |
for (i = 0; i < row_width; i++, sp += 2)
|
|
|
3621 |
{
|
|
|
3622 |
png_uint_16 a = *(sp + 1);
|
|
|
3623 |
|
|
|
3624 |
if (a == 0xff)
|
|
|
3625 |
*sp = gamma_table[*sp];
|
|
|
3626 |
|
|
|
3627 |
else if (a == 0)
|
|
|
3628 |
{
|
|
|
3629 |
/* Background is already in screen gamma */
|
|
|
3630 |
*sp = (png_byte)png_ptr->background.gray;
|
|
|
3631 |
}
|
|
|
3632 |
|
|
|
3633 |
else
|
|
|
3634 |
{
|
|
|
3635 |
png_byte v, w;
|
|
|
3636 |
|
|
|
3637 |
v = gamma_to_1[*sp];
|
|
|
3638 |
png_composite(w, v, a, png_ptr->background_1.gray);
|
|
29913
|
3639 |
if (optimize == 0)
|
|
10576
|
3640 |
w = gamma_from_1[w];
|
|
|
3641 |
*sp = w;
|
|
|
3642 |
}
|
|
|
3643 |
}
|
|
|
3644 |
}
|
|
2
|
3645 |
else
|
|
|
3646 |
#endif
|
|
|
3647 |
{
|
|
|
3648 |
sp = row;
|
|
10576
|
3649 |
for (i = 0; i < row_width; i++, sp += 2)
|
|
2
|
3650 |
{
|
|
10576
|
3651 |
png_byte a = *(sp + 1);
|
|
|
3652 |
|
|
|
3653 |
if (a == 0)
|
|
|
3654 |
*sp = (png_byte)png_ptr->background.gray;
|
|
|
3655 |
|
|
|
3656 |
else if (a < 0xff)
|
|
29913
|
3657 |
png_composite(*sp, *sp, a, png_ptr->background.gray);
|
|
2
|
3658 |
}
|
|
|
3659 |
}
|
|
|
3660 |
}
|
|
10576
|
3661 |
else /* if (png_ptr->bit_depth == 16) */
|
|
2
|
3662 |
{
|
|
10576
|
3663 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
|
3664 |
if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
|
|
|
3665 |
gamma_16_to_1 != NULL)
|
|
2
|
3666 |
{
|
|
|
3667 |
sp = row;
|
|
10576
|
3668 |
for (i = 0; i < row_width; i++, sp += 4)
|
|
2
|
3669 |
{
|
|
10576
|
3670 |
png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
|
|
|
3671 |
+ *(sp + 3));
|
|
|
3672 |
|
|
|
3673 |
if (a == (png_uint_16)0xffff)
|
|
2
|
3674 |
{
|
|
10576
|
3675 |
png_uint_16 v;
|
|
|
3676 |
|
|
|
3677 |
v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
|
|
|
3678 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
3679 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
2
|
3680 |
}
|
|
10576
|
3681 |
|
|
2
|
3682 |
else if (a == 0)
|
|
|
3683 |
{
|
|
10576
|
3684 |
/* Background is already in screen gamma */
|
|
29913
|
3685 |
*sp = (png_byte)((png_ptr->background.gray >> 8)
|
|
|
3686 |
& 0xff);
|
|
10576
|
3687 |
*(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
|
|
2
|
3688 |
}
|
|
10576
|
3689 |
|
|
2
|
3690 |
else
|
|
|
3691 |
{
|
|
10576
|
3692 |
png_uint_16 g, v, w;
|
|
|
3693 |
|
|
|
3694 |
g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
|
|
|
3695 |
png_composite_16(v, g, a, png_ptr->background_1.gray);
|
|
29913
|
3696 |
if (optimize != 0)
|
|
10576
|
3697 |
w = v;
|
|
|
3698 |
else
|
|
35296
|
3699 |
w = gamma_16_from_1[(v & 0xff) >>
|
|
|
3700 |
gamma_shift][v >> 8];
|
|
10576
|
3701 |
*sp = (png_byte)((w >> 8) & 0xff);
|
|
|
3702 |
*(sp + 1) = (png_byte)(w & 0xff);
|
|
2
|
3703 |
}
|
|
|
3704 |
}
|
|
|
3705 |
}
|
|
|
3706 |
else
|
|
|
3707 |
#endif
|
|
|
3708 |
{
|
|
|
3709 |
sp = row;
|
|
10576
|
3710 |
for (i = 0; i < row_width; i++, sp += 4)
|
|
2
|
3711 |
{
|
|
10576
|
3712 |
png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
|
|
|
3713 |
+ *(sp + 3));
|
|
|
3714 |
|
|
|
3715 |
if (a == 0)
|
|
2
|
3716 |
{
|
|
29913
|
3717 |
*sp = (png_byte)((png_ptr->background.gray >> 8)
|
|
|
3718 |
& 0xff);
|
|
10576
|
3719 |
*(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
|
|
2
|
3720 |
}
|
|
10576
|
3721 |
|
|
|
3722 |
else if (a < 0xffff)
|
|
2
|
3723 |
{
|
|
|
3724 |
png_uint_16 g, v;
|
|
|
3725 |
|
|
|
3726 |
g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
|
29913
|
3727 |
png_composite_16(v, g, a, png_ptr->background.gray);
|
|
10576
|
3728 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
3729 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
2
|
3730 |
}
|
|
|
3731 |
}
|
|
|
3732 |
}
|
|
|
3733 |
}
|
|
|
3734 |
break;
|
|
|
3735 |
}
|
|
10576
|
3736 |
|
|
2
|
3737 |
case PNG_COLOR_TYPE_RGB_ALPHA:
|
|
|
3738 |
{
|
|
|
3739 |
if (row_info->bit_depth == 8)
|
|
|
3740 |
{
|
|
10576
|
3741 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
2
|
3742 |
if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
|
|
|
3743 |
gamma_table != NULL)
|
|
|
3744 |
{
|
|
|
3745 |
sp = row;
|
|
10576
|
3746 |
for (i = 0; i < row_width; i++, sp += 4)
|
|
2
|
3747 |
{
|
|
|
3748 |
png_byte a = *(sp + 3);
|
|
|
3749 |
|
|
|
3750 |
if (a == 0xff)
|
|
|
3751 |
{
|
|
10576
|
3752 |
*sp = gamma_table[*sp];
|
|
|
3753 |
*(sp + 1) = gamma_table[*(sp + 1)];
|
|
|
3754 |
*(sp + 2) = gamma_table[*(sp + 2)];
|
|
2
|
3755 |
}
|
|
10576
|
3756 |
|
|
2
|
3757 |
else if (a == 0)
|
|
|
3758 |
{
|
|
10576
|
3759 |
/* Background is already in screen gamma */
|
|
|
3760 |
*sp = (png_byte)png_ptr->background.red;
|
|
|
3761 |
*(sp + 1) = (png_byte)png_ptr->background.green;
|
|
|
3762 |
*(sp + 2) = (png_byte)png_ptr->background.blue;
|
|
2
|
3763 |
}
|
|
10576
|
3764 |
|
|
2
|
3765 |
else
|
|
|
3766 |
{
|
|
|
3767 |
png_byte v, w;
|
|
|
3768 |
|
|
|
3769 |
v = gamma_to_1[*sp];
|
|
10576
|
3770 |
png_composite(w, v, a, png_ptr->background_1.red);
|
|
29913
|
3771 |
if (optimize == 0) w = gamma_from_1[w];
|
|
10576
|
3772 |
*sp = w;
|
|
|
3773 |
|
|
2
|
3774 |
v = gamma_to_1[*(sp + 1)];
|
|
10576
|
3775 |
png_composite(w, v, a, png_ptr->background_1.green);
|
|
29913
|
3776 |
if (optimize == 0) w = gamma_from_1[w];
|
|
10576
|
3777 |
*(sp + 1) = w;
|
|
|
3778 |
|
|
2
|
3779 |
v = gamma_to_1[*(sp + 2)];
|
|
10576
|
3780 |
png_composite(w, v, a, png_ptr->background_1.blue);
|
|
29913
|
3781 |
if (optimize == 0) w = gamma_from_1[w];
|
|
10576
|
3782 |
*(sp + 2) = w;
|
|
2
|
3783 |
}
|
|
|
3784 |
}
|
|
|
3785 |
}
|
|
|
3786 |
else
|
|
|
3787 |
#endif
|
|
|
3788 |
{
|
|
|
3789 |
sp = row;
|
|
10576
|
3790 |
for (i = 0; i < row_width; i++, sp += 4)
|
|
2
|
3791 |
{
|
|
|
3792 |
png_byte a = *(sp + 3);
|
|
|
3793 |
|
|
10576
|
3794 |
if (a == 0)
|
|
2
|
3795 |
{
|
|
10576
|
3796 |
*sp = (png_byte)png_ptr->background.red;
|
|
|
3797 |
*(sp + 1) = (png_byte)png_ptr->background.green;
|
|
|
3798 |
*(sp + 2) = (png_byte)png_ptr->background.blue;
|
|
2
|
3799 |
}
|
|
10576
|
3800 |
|
|
|
3801 |
else if (a < 0xff)
|
|
2
|
3802 |
{
|
|
10576
|
3803 |
png_composite(*sp, *sp, a, png_ptr->background.red);
|
|
|
3804 |
|
|
|
3805 |
png_composite(*(sp + 1), *(sp + 1), a,
|
|
|
3806 |
png_ptr->background.green);
|
|
|
3807 |
|
|
|
3808 |
png_composite(*(sp + 2), *(sp + 2), a,
|
|
|
3809 |
png_ptr->background.blue);
|
|
2
|
3810 |
}
|
|
|
3811 |
}
|
|
|
3812 |
}
|
|
|
3813 |
}
|
|
|
3814 |
else /* if (row_info->bit_depth == 16) */
|
|
|
3815 |
{
|
|
10576
|
3816 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
2
|
3817 |
if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
|
|
|
3818 |
gamma_16_to_1 != NULL)
|
|
|
3819 |
{
|
|
|
3820 |
sp = row;
|
|
10576
|
3821 |
for (i = 0; i < row_width; i++, sp += 8)
|
|
2
|
3822 |
{
|
|
|
3823 |
png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
|
|
|
3824 |
<< 8) + (png_uint_16)(*(sp + 7)));
|
|
10576
|
3825 |
|
|
2
|
3826 |
if (a == (png_uint_16)0xffff)
|
|
|
3827 |
{
|
|
|
3828 |
png_uint_16 v;
|
|
|
3829 |
|
|
|
3830 |
v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
|
|
10576
|
3831 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
3832 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
|
3833 |
|
|
2
|
3834 |
v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
|
|
10576
|
3835 |
*(sp + 2) = (png_byte)((v >> 8) & 0xff);
|
|
|
3836 |
*(sp + 3) = (png_byte)(v & 0xff);
|
|
|
3837 |
|
|
2
|
3838 |
v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
|
|
10576
|
3839 |
*(sp + 4) = (png_byte)((v >> 8) & 0xff);
|
|
|
3840 |
*(sp + 5) = (png_byte)(v & 0xff);
|
|
2
|
3841 |
}
|
|
10576
|
3842 |
|
|
2
|
3843 |
else if (a == 0)
|
|
|
3844 |
{
|
|
10576
|
3845 |
/* Background is already in screen gamma */
|
|
|
3846 |
*sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
|
|
|
3847 |
*(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
|
|
29913
|
3848 |
*(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
|
|
|
3849 |
& 0xff);
|
|
|
3850 |
*(sp + 3) = (png_byte)(png_ptr->background.green
|
|
|
3851 |
& 0xff);
|
|
|
3852 |
*(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
|
|
|
3853 |
& 0xff);
|
|
10576
|
3854 |
*(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
|
|
2
|
3855 |
}
|
|
10576
|
3856 |
|
|
2
|
3857 |
else
|
|
|
3858 |
{
|
|
10576
|
3859 |
png_uint_16 v, w;
|
|
2
|
3860 |
|
|
|
3861 |
v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
|
|
10576
|
3862 |
png_composite_16(w, v, a, png_ptr->background_1.red);
|
|
29913
|
3863 |
if (optimize == 0)
|
|
35296
|
3864 |
w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
|
|
29913
|
3865 |
8];
|
|
10576
|
3866 |
*sp = (png_byte)((w >> 8) & 0xff);
|
|
|
3867 |
*(sp + 1) = (png_byte)(w & 0xff);
|
|
|
3868 |
|
|
2
|
3869 |
v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
|
|
10576
|
3870 |
png_composite_16(w, v, a, png_ptr->background_1.green);
|
|
29913
|
3871 |
if (optimize == 0)
|
|
35296
|
3872 |
w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
|
|
29913
|
3873 |
8];
|
|
10576
|
3874 |
|
|
|
3875 |
*(sp + 2) = (png_byte)((w >> 8) & 0xff);
|
|
|
3876 |
*(sp + 3) = (png_byte)(w & 0xff);
|
|
|
3877 |
|
|
2
|
3878 |
v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
|
|
10576
|
3879 |
png_composite_16(w, v, a, png_ptr->background_1.blue);
|
|
29913
|
3880 |
if (optimize == 0)
|
|
35296
|
3881 |
w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
|
|
29913
|
3882 |
8];
|
|
10576
|
3883 |
|
|
|
3884 |
*(sp + 4) = (png_byte)((w >> 8) & 0xff);
|
|
|
3885 |
*(sp + 5) = (png_byte)(w & 0xff);
|
|
2
|
3886 |
}
|
|
|
3887 |
}
|
|
|
3888 |
}
|
|
10576
|
3889 |
|
|
2
|
3890 |
else
|
|
|
3891 |
#endif
|
|
|
3892 |
{
|
|
|
3893 |
sp = row;
|
|
10576
|
3894 |
for (i = 0; i < row_width; i++, sp += 8)
|
|
2
|
3895 |
{
|
|
|
3896 |
png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
|
|
10576
|
3897 |
<< 8) + (png_uint_16)(*(sp + 7)));
|
|
|
3898 |
|
|
|
3899 |
if (a == 0)
|
|
2
|
3900 |
{
|
|
10576
|
3901 |
*sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
|
|
|
3902 |
*(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
|
|
29913
|
3903 |
*(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
|
|
|
3904 |
& 0xff);
|
|
|
3905 |
*(sp + 3) = (png_byte)(png_ptr->background.green
|
|
|
3906 |
& 0xff);
|
|
|
3907 |
*(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
|
|
|
3908 |
& 0xff);
|
|
10576
|
3909 |
*(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
|
|
2
|
3910 |
}
|
|
10576
|
3911 |
|
|
|
3912 |
else if (a < 0xffff)
|
|
2
|
3913 |
{
|
|
|
3914 |
png_uint_16 v;
|
|
|
3915 |
|
|
|
3916 |
png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
|
|
3917 |
png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
|
|
|
3918 |
+ *(sp + 3));
|
|
|
3919 |
png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
|
|
|
3920 |
+ *(sp + 5));
|
|
|
3921 |
|
|
10576
|
3922 |
png_composite_16(v, r, a, png_ptr->background.red);
|
|
|
3923 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
3924 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
|
3925 |
|
|
|
3926 |
png_composite_16(v, g, a, png_ptr->background.green);
|
|
|
3927 |
*(sp + 2) = (png_byte)((v >> 8) & 0xff);
|
|
|
3928 |
*(sp + 3) = (png_byte)(v & 0xff);
|
|
|
3929 |
|
|
|
3930 |
png_composite_16(v, b, a, png_ptr->background.blue);
|
|
|
3931 |
*(sp + 4) = (png_byte)((v >> 8) & 0xff);
|
|
|
3932 |
*(sp + 5) = (png_byte)(v & 0xff);
|
|
2
|
3933 |
}
|
|
|
3934 |
}
|
|
|
3935 |
}
|
|
|
3936 |
}
|
|
|
3937 |
break;
|
|
|
3938 |
}
|
|
10576
|
3939 |
|
|
|
3940 |
default:
|
|
|
3941 |
break;
|
|
2
|
3942 |
}
|
|
|
3943 |
}
|
|
|
3944 |
}
|
|
29913
|
3945 |
#endif /* READ_BACKGROUND || READ_ALPHA_MODE */
|
|
2
|
3946 |
|
|
10576
|
3947 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
2
|
3948 |
/* Gamma correct the image, avoiding the alpha channel. Make sure
|
|
|
3949 |
* you do this after you deal with the transparency issue on grayscale
|
|
|
3950 |
* or RGB images. If your bit depth is 8, use gamma_table, if it
|
|
|
3951 |
* is 16, use gamma_16_table and gamma_shift. Build these with
|
|
|
3952 |
* build_gamma_table().
|
|
|
3953 |
*/
|
|
29913
|
3954 |
static void
|
|
|
3955 |
png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
|
|
2
|
3956 |
{
|
|
10576
|
3957 |
png_const_bytep gamma_table = png_ptr->gamma_table;
|
|
|
3958 |
png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table;
|
|
|
3959 |
int gamma_shift = png_ptr->gamma_shift;
|
|
|
3960 |
|
|
2
|
3961 |
png_bytep sp;
|
|
|
3962 |
png_uint_32 i;
|
|
|
3963 |
png_uint_32 row_width=row_info->width;
|
|
|
3964 |
|
|
10576
|
3965 |
png_debug(1, "in png_do_gamma");
|
|
|
3966 |
|
|
|
3967 |
if (((row_info->bit_depth <= 8 && gamma_table != NULL) ||
|
|
|
3968 |
(row_info->bit_depth == 16 && gamma_16_table != NULL)))
|
|
2
|
3969 |
{
|
|
|
3970 |
switch (row_info->color_type)
|
|
|
3971 |
{
|
|
|
3972 |
case PNG_COLOR_TYPE_RGB:
|
|
|
3973 |
{
|
|
|
3974 |
if (row_info->bit_depth == 8)
|
|
|
3975 |
{
|
|
|
3976 |
sp = row;
|
|
|
3977 |
for (i = 0; i < row_width; i++)
|
|
|
3978 |
{
|
|
|
3979 |
*sp = gamma_table[*sp];
|
|
|
3980 |
sp++;
|
|
|
3981 |
*sp = gamma_table[*sp];
|
|
|
3982 |
sp++;
|
|
|
3983 |
*sp = gamma_table[*sp];
|
|
|
3984 |
sp++;
|
|
|
3985 |
}
|
|
|
3986 |
}
|
|
10576
|
3987 |
|
|
2
|
3988 |
else /* if (row_info->bit_depth == 16) */
|
|
|
3989 |
{
|
|
|
3990 |
sp = row;
|
|
|
3991 |
for (i = 0; i < row_width; i++)
|
|
|
3992 |
{
|
|
|
3993 |
png_uint_16 v;
|
|
|
3994 |
|
|
|
3995 |
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
|
3996 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
3997 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
|
3998 |
sp += 2;
|
|
10576
|
3999 |
|
|
2
|
4000 |
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
|
4001 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
4002 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
|
4003 |
sp += 2;
|
|
10576
|
4004 |
|
|
2
|
4005 |
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
|
4006 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
4007 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
|
4008 |
sp += 2;
|
|
|
4009 |
}
|
|
|
4010 |
}
|
|
|
4011 |
break;
|
|
|
4012 |
}
|
|
10576
|
4013 |
|
|
2
|
4014 |
case PNG_COLOR_TYPE_RGB_ALPHA:
|
|
|
4015 |
{
|
|
|
4016 |
if (row_info->bit_depth == 8)
|
|
|
4017 |
{
|
|
|
4018 |
sp = row;
|
|
|
4019 |
for (i = 0; i < row_width; i++)
|
|
|
4020 |
{
|
|
|
4021 |
*sp = gamma_table[*sp];
|
|
|
4022 |
sp++;
|
|
10576
|
4023 |
|
|
2
|
4024 |
*sp = gamma_table[*sp];
|
|
|
4025 |
sp++;
|
|
10576
|
4026 |
|
|
2
|
4027 |
*sp = gamma_table[*sp];
|
|
|
4028 |
sp++;
|
|
10576
|
4029 |
|
|
2
|
4030 |
sp++;
|
|
|
4031 |
}
|
|
|
4032 |
}
|
|
10576
|
4033 |
|
|
2
|
4034 |
else /* if (row_info->bit_depth == 16) */
|
|
|
4035 |
{
|
|
|
4036 |
sp = row;
|
|
|
4037 |
for (i = 0; i < row_width; i++)
|
|
|
4038 |
{
|
|
|
4039 |
png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
|
4040 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
4041 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
|
4042 |
sp += 2;
|
|
10576
|
4043 |
|
|
2
|
4044 |
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
|
4045 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
4046 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
|
4047 |
sp += 2;
|
|
10576
|
4048 |
|
|
2
|
4049 |
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
|
4050 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
4051 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
|
4052 |
sp += 4;
|
|
|
4053 |
}
|
|
|
4054 |
}
|
|
|
4055 |
break;
|
|
|
4056 |
}
|
|
10576
|
4057 |
|
|
2
|
4058 |
case PNG_COLOR_TYPE_GRAY_ALPHA:
|
|
|
4059 |
{
|
|
|
4060 |
if (row_info->bit_depth == 8)
|
|
|
4061 |
{
|
|
|
4062 |
sp = row;
|
|
|
4063 |
for (i = 0; i < row_width; i++)
|
|
|
4064 |
{
|
|
|
4065 |
*sp = gamma_table[*sp];
|
|
|
4066 |
sp += 2;
|
|
|
4067 |
}
|
|
|
4068 |
}
|
|
10576
|
4069 |
|
|
2
|
4070 |
else /* if (row_info->bit_depth == 16) */
|
|
|
4071 |
{
|
|
|
4072 |
sp = row;
|
|
|
4073 |
for (i = 0; i < row_width; i++)
|
|
|
4074 |
{
|
|
|
4075 |
png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
|
4076 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
4077 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
|
4078 |
sp += 4;
|
|
|
4079 |
}
|
|
|
4080 |
}
|
|
|
4081 |
break;
|
|
|
4082 |
}
|
|
10576
|
4083 |
|
|
2
|
4084 |
case PNG_COLOR_TYPE_GRAY:
|
|
|
4085 |
{
|
|
|
4086 |
if (row_info->bit_depth == 2)
|
|
|
4087 |
{
|
|
|
4088 |
sp = row;
|
|
|
4089 |
for (i = 0; i < row_width; i += 4)
|
|
|
4090 |
{
|
|
|
4091 |
int a = *sp & 0xc0;
|
|
|
4092 |
int b = *sp & 0x30;
|
|
|
4093 |
int c = *sp & 0x0c;
|
|
|
4094 |
int d = *sp & 0x03;
|
|
|
4095 |
|
|
|
4096 |
*sp = (png_byte)(
|
|
10576
|
4097 |
((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|
|
|
|
4098 |
((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
|
|
|
4099 |
((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
|
|
|
4100 |
((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
|
|
2
|
4101 |
sp++;
|
|
|
4102 |
}
|
|
|
4103 |
}
|
|
10576
|
4104 |
|
|
2
|
4105 |
if (row_info->bit_depth == 4)
|
|
|
4106 |
{
|
|
|
4107 |
sp = row;
|
|
|
4108 |
for (i = 0; i < row_width; i += 2)
|
|
|
4109 |
{
|
|
|
4110 |
int msb = *sp & 0xf0;
|
|
|
4111 |
int lsb = *sp & 0x0f;
|
|
|
4112 |
|
|
|
4113 |
*sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
|
|
10576
|
4114 |
| (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
|
|
2
|
4115 |
sp++;
|
|
|
4116 |
}
|
|
|
4117 |
}
|
|
10576
|
4118 |
|
|
2
|
4119 |
else if (row_info->bit_depth == 8)
|
|
|
4120 |
{
|
|
|
4121 |
sp = row;
|
|
|
4122 |
for (i = 0; i < row_width; i++)
|
|
|
4123 |
{
|
|
|
4124 |
*sp = gamma_table[*sp];
|
|
|
4125 |
sp++;
|
|
|
4126 |
}
|
|
|
4127 |
}
|
|
10576
|
4128 |
|
|
2
|
4129 |
else if (row_info->bit_depth == 16)
|
|
|
4130 |
{
|
|
|
4131 |
sp = row;
|
|
|
4132 |
for (i = 0; i < row_width; i++)
|
|
|
4133 |
{
|
|
|
4134 |
png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
|
4135 |
*sp = (png_byte)((v >> 8) & 0xff);
|
|
|
4136 |
*(sp + 1) = (png_byte)(v & 0xff);
|
|
|
4137 |
sp += 2;
|
|
|
4138 |
}
|
|
|
4139 |
}
|
|
|
4140 |
break;
|
|
|
4141 |
}
|
|
10576
|
4142 |
|
|
|
4143 |
default:
|
|
|
4144 |
break;
|
|
2
|
4145 |
}
|
|
|
4146 |
}
|
|
|
4147 |
}
|
|
|
4148 |
#endif
|
|
|
4149 |
|
|
10576
|
4150 |
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
|
|
|
4151 |
/* Encode the alpha channel to the output gamma (the input channel is always
|
|
|
4152 |
* linear.) Called only with color types that have an alpha channel. Needs the
|
|
|
4153 |
* from_1 tables.
|
|
|
4154 |
*/
|
|
29913
|
4155 |
static void
|
|
|
4156 |
png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
|
|
10576
|
4157 |
{
|
|
|
4158 |
png_uint_32 row_width = row_info->width;
|
|
|
4159 |
|
|
|
4160 |
png_debug(1, "in png_do_encode_alpha");
|
|
|
4161 |
|
|
29913
|
4162 |
if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
|
|
10576
|
4163 |
{
|
|
|
4164 |
if (row_info->bit_depth == 8)
|
|
|
4165 |
{
|
|
|
4166 |
PNG_CONST png_bytep table = png_ptr->gamma_from_1;
|
|
|
4167 |
|
|
|
4168 |
if (table != NULL)
|
|
|
4169 |
{
|
|
|
4170 |
PNG_CONST int step =
|
|
|
4171 |
(row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2;
|
|
|
4172 |
|
|
|
4173 |
/* The alpha channel is the last component: */
|
|
|
4174 |
row += step - 1;
|
|
|
4175 |
|
|
|
4176 |
for (; row_width > 0; --row_width, row += step)
|
|
|
4177 |
*row = table[*row];
|
|
|
4178 |
|
|
|
4179 |
return;
|
|
|
4180 |
}
|
|
|
4181 |
}
|
|
|
4182 |
|
|
|
4183 |
else if (row_info->bit_depth == 16)
|
|
|
4184 |
{
|
|
|
4185 |
PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1;
|
|
|
4186 |
PNG_CONST int gamma_shift = png_ptr->gamma_shift;
|
|
|
4187 |
|
|
|
4188 |
if (table != NULL)
|
|
|
4189 |
{
|
|
|
4190 |
PNG_CONST int step =
|
|
|
4191 |
(row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4;
|
|
|
4192 |
|
|
|
4193 |
/* The alpha channel is the last component: */
|
|
|
4194 |
row += step - 2;
|
|
|
4195 |
|
|
|
4196 |
for (; row_width > 0; --row_width, row += step)
|
|
|
4197 |
{
|
|
|
4198 |
png_uint_16 v;
|
|
|
4199 |
|
|
|
4200 |
v = table[*(row + 1) >> gamma_shift][*row];
|
|
|
4201 |
*row = (png_byte)((v >> 8) & 0xff);
|
|
|
4202 |
*(row + 1) = (png_byte)(v & 0xff);
|
|
|
4203 |
}
|
|
|
4204 |
|
|
|
4205 |
return;
|
|
|
4206 |
}
|
|
|
4207 |
}
|
|
|
4208 |
}
|
|
|
4209 |
|
|
|
4210 |
/* Only get to here if called with a weird row_info; no harm has been done,
|
|
|
4211 |
* so just issue a warning.
|
|
|
4212 |
*/
|
|
|
4213 |
png_warning(png_ptr, "png_do_encode_alpha: unexpected call");
|
|
|
4214 |
}
|
|
|
4215 |
#endif
|
|
|
4216 |
|
|
|
4217 |
#ifdef PNG_READ_EXPAND_SUPPORTED
|
|
2
|
4218 |
/* Expands a palette row to an RGB or RGBA row depending
|
|
|
4219 |
* upon whether you supply trans and num_trans.
|
|
|
4220 |
*/
|
|
29913
|
4221 |
static void
|
|
2
|
4222 |
png_do_expand_palette(png_row_infop row_info, png_bytep row,
|
|
10576
|
4223 |
png_const_colorp palette, png_const_bytep trans_alpha, int num_trans)
|
|
2
|
4224 |
{
|
|
|
4225 |
int shift, value;
|
|
|
4226 |
png_bytep sp, dp;
|
|
|
4227 |
png_uint_32 i;
|
|
|
4228 |
png_uint_32 row_width=row_info->width;
|
|
|
4229 |
|
|
10576
|
4230 |
png_debug(1, "in png_do_expand_palette");
|
|
|
4231 |
|
|
|
4232 |
if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
2
|
4233 |
{
|
|
|
4234 |
if (row_info->bit_depth < 8)
|
|
|
4235 |
{
|
|
|
4236 |
switch (row_info->bit_depth)
|
|
|
4237 |
{
|
|
|
4238 |
case 1:
|
|
|
4239 |
{
|
|
|
4240 |
sp = row + (png_size_t)((row_width - 1) >> 3);
|
|
|
4241 |
dp = row + (png_size_t)row_width - 1;
|
|
|
4242 |
shift = 7 - (int)((row_width + 7) & 0x07);
|
|
|
4243 |
for (i = 0; i < row_width; i++)
|
|
|
4244 |
{
|
|
|
4245 |
if ((*sp >> shift) & 0x01)
|
|
|
4246 |
*dp = 1;
|
|
10576
|
4247 |
|
|
2
|
4248 |
else
|
|
|
4249 |
*dp = 0;
|
|
10576
|
4250 |
|
|
2
|
4251 |
if (shift == 7)
|
|
|
4252 |
{
|
|
|
4253 |
shift = 0;
|
|
|
4254 |
sp--;
|
|
|
4255 |
}
|
|
10576
|
4256 |
|
|
2
|
4257 |
else
|
|
|
4258 |
shift++;
|
|
|
4259 |
|
|
|
4260 |
dp--;
|
|
|
4261 |
}
|
|
|
4262 |
break;
|
|
|
4263 |
}
|
|
10576
|
4264 |
|
|
2
|
4265 |
case 2:
|
|
|
4266 |
{
|
|
|
4267 |
sp = row + (png_size_t)((row_width - 1) >> 2);
|
|
|
4268 |
dp = row + (png_size_t)row_width - 1;
|
|
|
4269 |
shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
|
|
|
4270 |
for (i = 0; i < row_width; i++)
|
|
|
4271 |
{
|
|
|
4272 |
value = (*sp >> shift) & 0x03;
|
|
|
4273 |
*dp = (png_byte)value;
|
|
|
4274 |
if (shift == 6)
|
|
|
4275 |
{
|
|
|
4276 |
shift = 0;
|
|
|
4277 |
sp--;
|
|
|
4278 |
}
|
|
10576
|
4279 |
|
|
2
|
4280 |
else
|
|
|
4281 |
shift += 2;
|
|
|
4282 |
|
|
|
4283 |
dp--;
|
|
|
4284 |
}
|
|
|
4285 |
break;
|
|
|
4286 |
}
|
|
10576
|
4287 |
|
|
2
|
4288 |
case 4:
|
|
|
4289 |
{
|
|
|
4290 |
sp = row + (png_size_t)((row_width - 1) >> 1);
|
|
|
4291 |
dp = row + (png_size_t)row_width - 1;
|
|
|
4292 |
shift = (int)((row_width & 0x01) << 2);
|
|
|
4293 |
for (i = 0; i < row_width; i++)
|
|
|
4294 |
{
|
|
|
4295 |
value = (*sp >> shift) & 0x0f;
|
|
|
4296 |
*dp = (png_byte)value;
|
|
|
4297 |
if (shift == 4)
|
|
|
4298 |
{
|
|
|
4299 |
shift = 0;
|
|
|
4300 |
sp--;
|
|
|
4301 |
}
|
|
10576
|
4302 |
|
|
2
|
4303 |
else
|
|
|
4304 |
shift += 4;
|
|
|
4305 |
|
|
|
4306 |
dp--;
|
|
|
4307 |
}
|
|
|
4308 |
break;
|
|
|
4309 |
}
|
|
10576
|
4310 |
|
|
|
4311 |
default:
|
|
|
4312 |
break;
|
|
2
|
4313 |
}
|
|
|
4314 |
row_info->bit_depth = 8;
|
|
|
4315 |
row_info->pixel_depth = 8;
|
|
|
4316 |
row_info->rowbytes = row_width;
|
|
|
4317 |
}
|
|
10576
|
4318 |
|
|
|
4319 |
if (row_info->bit_depth == 8)
|
|
2
|
4320 |
{
|
|
|
4321 |
{
|
|
10576
|
4322 |
if (num_trans > 0)
|
|
2
|
4323 |
{
|
|
|
4324 |
sp = row + (png_size_t)row_width - 1;
|
|
|
4325 |
dp = row + (png_size_t)(row_width << 2) - 1;
|
|
|
4326 |
|
|
|
4327 |
for (i = 0; i < row_width; i++)
|
|
|
4328 |
{
|
|
|
4329 |
if ((int)(*sp) >= num_trans)
|
|
|
4330 |
*dp-- = 0xff;
|
|
10576
|
4331 |
|
|
2
|
4332 |
else
|
|
10576
|
4333 |
*dp-- = trans_alpha[*sp];
|
|
|
4334 |
|
|
2
|
4335 |
*dp-- = palette[*sp].blue;
|
|
|
4336 |
*dp-- = palette[*sp].green;
|
|
|
4337 |
*dp-- = palette[*sp].red;
|
|
|
4338 |
sp--;
|
|
|
4339 |
}
|
|
|
4340 |
row_info->bit_depth = 8;
|
|
|
4341 |
row_info->pixel_depth = 32;
|
|
|
4342 |
row_info->rowbytes = row_width * 4;
|
|
|
4343 |
row_info->color_type = 6;
|
|
|
4344 |
row_info->channels = 4;
|
|
|
4345 |
}
|
|
10576
|
4346 |
|
|
2
|
4347 |
else
|
|
|
4348 |
{
|
|
|
4349 |
sp = row + (png_size_t)row_width - 1;
|
|
|
4350 |
dp = row + (png_size_t)(row_width * 3) - 1;
|
|
|
4351 |
|
|
|
4352 |
for (i = 0; i < row_width; i++)
|
|
|
4353 |
{
|
|
|
4354 |
*dp-- = palette[*sp].blue;
|
|
|
4355 |
*dp-- = palette[*sp].green;
|
|
|
4356 |
*dp-- = palette[*sp].red;
|
|
|
4357 |
sp--;
|
|
|
4358 |
}
|
|
10576
|
4359 |
|
|
2
|
4360 |
row_info->bit_depth = 8;
|
|
|
4361 |
row_info->pixel_depth = 24;
|
|
|
4362 |
row_info->rowbytes = row_width * 3;
|
|
|
4363 |
row_info->color_type = 2;
|
|
|
4364 |
row_info->channels = 3;
|
|
|
4365 |
}
|
|
|
4366 |
}
|
|
|
4367 |
}
|
|
|
4368 |
}
|
|
|
4369 |
}
|
|
|
4370 |
|
|
|
4371 |
/* If the bit depth < 8, it is expanded to 8. Also, if the already
|
|
|
4372 |
* expanded transparency value is supplied, an alpha channel is built.
|
|
|
4373 |
*/
|
|
29913
|
4374 |
static void
|
|
2
|
4375 |
png_do_expand(png_row_infop row_info, png_bytep row,
|
|
10576
|
4376 |
png_const_color_16p trans_color)
|
|
2
|
4377 |
{
|
|
|
4378 |
int shift, value;
|
|
|
4379 |
png_bytep sp, dp;
|
|
|
4380 |
png_uint_32 i;
|
|
|
4381 |
png_uint_32 row_width=row_info->width;
|
|
|
4382 |
|
|
10576
|
4383 |
png_debug(1, "in png_do_expand");
|
|
|
4384 |
|
|
2
|
4385 |
{
|
|
|
4386 |
if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
|
|
|
4387 |
{
|
|
29913
|
4388 |
unsigned int gray = trans_color != NULL ? trans_color->gray : 0;
|
|
2
|
4389 |
|
|
|
4390 |
if (row_info->bit_depth < 8)
|
|
|
4391 |
{
|
|
|
4392 |
switch (row_info->bit_depth)
|
|
|
4393 |
{
|
|
|
4394 |
case 1:
|
|
|
4395 |
{
|
|
29913
|
4396 |
gray = (gray & 0x01) * 0xff;
|
|
2
|
4397 |
sp = row + (png_size_t)((row_width - 1) >> 3);
|
|
|
4398 |
dp = row + (png_size_t)row_width - 1;
|
|
|
4399 |
shift = 7 - (int)((row_width + 7) & 0x07);
|
|
|
4400 |
for (i = 0; i < row_width; i++)
|
|
|
4401 |
{
|
|
|
4402 |
if ((*sp >> shift) & 0x01)
|
|
|
4403 |
*dp = 0xff;
|
|
10576
|
4404 |
|
|
2
|
4405 |
else
|
|
|
4406 |
*dp = 0;
|
|
10576
|
4407 |
|
|
2
|
4408 |
if (shift == 7)
|
|
|
4409 |
{
|
|
|
4410 |
shift = 0;
|
|
|
4411 |
sp--;
|
|
|
4412 |
}
|
|
10576
|
4413 |
|
|
2
|
4414 |
else
|
|
|
4415 |
shift++;
|
|
|
4416 |
|
|
|
4417 |
dp--;
|
|
|
4418 |
}
|
|
|
4419 |
break;
|
|
|
4420 |
}
|
|
10576
|
4421 |
|
|
2
|
4422 |
case 2:
|
|
|
4423 |
{
|
|
29913
|
4424 |
gray = (gray & 0x03) * 0x55;
|
|
2
|
4425 |
sp = row + (png_size_t)((row_width - 1) >> 2);
|
|
|
4426 |
dp = row + (png_size_t)row_width - 1;
|
|
|
4427 |
shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
|
|
|
4428 |
for (i = 0; i < row_width; i++)
|
|
|
4429 |
{
|
|
|
4430 |
value = (*sp >> shift) & 0x03;
|
|
|
4431 |
*dp = (png_byte)(value | (value << 2) | (value << 4) |
|
|
|
4432 |
(value << 6));
|
|
|
4433 |
if (shift == 6)
|
|
|
4434 |
{
|
|
|
4435 |
shift = 0;
|
|
|
4436 |
sp--;
|
|
|
4437 |
}
|
|
10576
|
4438 |
|
|
2
|
4439 |
else
|
|
|
4440 |
shift += 2;
|
|
|
4441 |
|
|
|
4442 |
dp--;
|
|
|
4443 |
}
|
|
|
4444 |
break;
|
|
|
4445 |
}
|
|
10576
|
4446 |
|
|
2
|
4447 |
case 4:
|
|
|
4448 |
{
|
|
29913
|
4449 |
gray = (gray & 0x0f) * 0x11;
|
|
2
|
4450 |
sp = row + (png_size_t)((row_width - 1) >> 1);
|
|
|
4451 |
dp = row + (png_size_t)row_width - 1;
|
|
|
4452 |
shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
|
|
|
4453 |
for (i = 0; i < row_width; i++)
|
|
|
4454 |
{
|
|
|
4455 |
value = (*sp >> shift) & 0x0f;
|
|
|
4456 |
*dp = (png_byte)(value | (value << 4));
|
|
|
4457 |
if (shift == 4)
|
|
|
4458 |
{
|
|
|
4459 |
shift = 0;
|
|
|
4460 |
sp--;
|
|
|
4461 |
}
|
|
10576
|
4462 |
|
|
2
|
4463 |
else
|
|
|
4464 |
shift = 4;
|
|
|
4465 |
|
|
|
4466 |
dp--;
|
|
|
4467 |
}
|
|
|
4468 |
break;
|
|
|
4469 |
}
|
|
10576
|
4470 |
|
|
|
4471 |
default:
|
|
|
4472 |
break;
|
|
2
|
4473 |
}
|
|
10576
|
4474 |
|
|
2
|
4475 |
row_info->bit_depth = 8;
|
|
|
4476 |
row_info->pixel_depth = 8;
|
|
|
4477 |
row_info->rowbytes = row_width;
|
|
|
4478 |
}
|
|
|
4479 |
|
|
10576
|
4480 |
if (trans_color != NULL)
|
|
2
|
4481 |
{
|
|
|
4482 |
if (row_info->bit_depth == 8)
|
|
|
4483 |
{
|
|
10576
|
4484 |
gray = gray & 0xff;
|
|
2
|
4485 |
sp = row + (png_size_t)row_width - 1;
|
|
|
4486 |
dp = row + (png_size_t)(row_width << 1) - 1;
|
|
10576
|
4487 |
|
|
2
|
4488 |
for (i = 0; i < row_width; i++)
|
|
|
4489 |
{
|
|
35296
|
4490 |
if ((*sp & 0xffU) == gray)
|
|
2
|
4491 |
*dp-- = 0;
|
|
10576
|
4492 |
|
|
2
|
4493 |
else
|
|
|
4494 |
*dp-- = 0xff;
|
|
10576
|
4495 |
|
|
2
|
4496 |
*dp-- = *sp--;
|
|
|
4497 |
}
|
|
|
4498 |
}
|
|
10576
|
4499 |
|
|
2
|
4500 |
else if (row_info->bit_depth == 16)
|
|
|
4501 |
{
|
|
29913
|
4502 |
unsigned int gray_high = (gray >> 8) & 0xff;
|
|
|
4503 |
unsigned int gray_low = gray & 0xff;
|
|
2
|
4504 |
sp = row + row_info->rowbytes - 1;
|
|
|
4505 |
dp = row + (row_info->rowbytes << 1) - 1;
|
|
|
4506 |
for (i = 0; i < row_width; i++)
|
|
|
4507 |
{
|
|
35296
|
4508 |
if ((*(sp - 1) & 0xffU) == gray_high &&
|
|
|
4509 |
(*(sp) & 0xffU) == gray_low)
|
|
2
|
4510 |
{
|
|
|
4511 |
*dp-- = 0;
|
|
|
4512 |
*dp-- = 0;
|
|
|
4513 |
}
|
|
10576
|
4514 |
|
|
2
|
4515 |
else
|
|
|
4516 |
{
|
|
|
4517 |
*dp-- = 0xff;
|
|
|
4518 |
*dp-- = 0xff;
|
|
|
4519 |
}
|
|
10576
|
4520 |
|
|
2
|
4521 |
*dp-- = *sp--;
|
|
|
4522 |
*dp-- = *sp--;
|
|
|
4523 |
}
|
|
|
4524 |
}
|
|
10576
|
4525 |
|
|
2
|
4526 |
row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
|
|
|
4527 |
row_info->channels = 2;
|
|
|
4528 |
row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
|
|
|
4529 |
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
|
|
|
4530 |
row_width);
|
|
|
4531 |
}
|
|
|
4532 |
}
|
|
29913
|
4533 |
else if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
|
|
|
4534 |
trans_color != NULL)
|
|
2
|
4535 |
{
|
|
|
4536 |
if (row_info->bit_depth == 8)
|
|
|
4537 |
{
|
|
10576
|
4538 |
png_byte red = (png_byte)(trans_color->red & 0xff);
|
|
|
4539 |
png_byte green = (png_byte)(trans_color->green & 0xff);
|
|
|
4540 |
png_byte blue = (png_byte)(trans_color->blue & 0xff);
|
|
2
|
4541 |
sp = row + (png_size_t)row_info->rowbytes - 1;
|
|
|
4542 |
dp = row + (png_size_t)(row_width << 2) - 1;
|
|
|
4543 |
for (i = 0; i < row_width; i++)
|
|
|
4544 |
{
|
|
10576
|
4545 |
if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
|
|
2
|
4546 |
*dp-- = 0;
|
|
10576
|
4547 |
|
|
2
|
4548 |
else
|
|
|
4549 |
*dp-- = 0xff;
|
|
10576
|
4550 |
|
|
2
|
4551 |
*dp-- = *sp--;
|
|
|
4552 |
*dp-- = *sp--;
|
|
|
4553 |
*dp-- = *sp--;
|
|
|
4554 |
}
|
|
|
4555 |
}
|
|
|
4556 |
else if (row_info->bit_depth == 16)
|
|
|
4557 |
{
|
|
10576
|
4558 |
png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff);
|
|
|
4559 |
png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff);
|
|
|
4560 |
png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff);
|
|
|
4561 |
png_byte red_low = (png_byte)(trans_color->red & 0xff);
|
|
|
4562 |
png_byte green_low = (png_byte)(trans_color->green & 0xff);
|
|
|
4563 |
png_byte blue_low = (png_byte)(trans_color->blue & 0xff);
|
|
2
|
4564 |
sp = row + row_info->rowbytes - 1;
|
|
|
4565 |
dp = row + (png_size_t)(row_width << 3) - 1;
|
|
|
4566 |
for (i = 0; i < row_width; i++)
|
|
|
4567 |
{
|
|
10576
|
4568 |
if (*(sp - 5) == red_high &&
|
|
|
4569 |
*(sp - 4) == red_low &&
|
|
|
4570 |
*(sp - 3) == green_high &&
|
|
|
4571 |
*(sp - 2) == green_low &&
|
|
|
4572 |
*(sp - 1) == blue_high &&
|
|
|
4573 |
*(sp ) == blue_low)
|
|
2
|
4574 |
{
|
|
|
4575 |
*dp-- = 0;
|
|
|
4576 |
*dp-- = 0;
|
|
|
4577 |
}
|
|
10576
|
4578 |
|
|
2
|
4579 |
else
|
|
|
4580 |
{
|
|
|
4581 |
*dp-- = 0xff;
|
|
|
4582 |
*dp-- = 0xff;
|
|
|
4583 |
}
|
|
10576
|
4584 |
|
|
2
|
4585 |
*dp-- = *sp--;
|
|
|
4586 |
*dp-- = *sp--;
|
|
|
4587 |
*dp-- = *sp--;
|
|
|
4588 |
*dp-- = *sp--;
|
|
|
4589 |
*dp-- = *sp--;
|
|
|
4590 |
*dp-- = *sp--;
|
|
|
4591 |
}
|
|
|
4592 |
}
|
|
|
4593 |
row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
|
|
|
4594 |
row_info->channels = 4;
|
|
|
4595 |
row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
|
|
10576
|
4596 |
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
|
2
|
4597 |
}
|
|
|
4598 |
}
|
|
|
4599 |
}
|
|
|
4600 |
#endif
|
|
|
4601 |
|
|
10576
|
4602 |
#ifdef PNG_READ_EXPAND_16_SUPPORTED
|
|
29913
|
4603 |
/* If the bit depth is 8 and the color type is not a palette type expand the
|
|
10576
|
4604 |
* whole row to 16 bits. Has no effect otherwise.
|
|
|
4605 |
*/
|
|
29913
|
4606 |
static void
|
|
10576
|
4607 |
png_do_expand_16(png_row_infop row_info, png_bytep row)
|
|
|
4608 |
{
|
|
|
4609 |
if (row_info->bit_depth == 8 &&
|
|
|
4610 |
row_info->color_type != PNG_COLOR_TYPE_PALETTE)
|
|
|
4611 |
{
|
|
|
4612 |
/* The row have a sequence of bytes containing [0..255] and we need
|
|
|
4613 |
* to turn it into another row containing [0..65535], to do this we
|
|
|
4614 |
* calculate:
|
|
|
4615 |
*
|
|
|
4616 |
* (input / 255) * 65535
|
|
|
4617 |
*
|
|
|
4618 |
* Which happens to be exactly input * 257 and this can be achieved
|
|
|
4619 |
* simply by byte replication in place (copying backwards).
|
|
|
4620 |
*/
|
|
|
4621 |
png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */
|
|
|
4622 |
png_byte *dp = sp + row_info->rowbytes; /* destination, end + 1 */
|
|
|
4623 |
while (dp > sp)
|
|
|
4624 |
dp[-2] = dp[-1] = *--sp, dp -= 2;
|
|
|
4625 |
|
|
|
4626 |
row_info->rowbytes *= 2;
|
|
|
4627 |
row_info->bit_depth = 16;
|
|
|
4628 |
row_info->pixel_depth = (png_byte)(row_info->channels * 16);
|
|
|
4629 |
}
|
|
|
4630 |
}
|
|
|
4631 |
#endif
|
|
|
4632 |
|
|
|
4633 |
#ifdef PNG_READ_QUANTIZE_SUPPORTED
|
|
29913
|
4634 |
static void
|
|
10576
|
4635 |
png_do_quantize(png_row_infop row_info, png_bytep row,
|
|
|
4636 |
png_const_bytep palette_lookup, png_const_bytep quantize_lookup)
|
|
2
|
4637 |
{
|
|
|
4638 |
png_bytep sp, dp;
|
|
|
4639 |
png_uint_32 i;
|
|
|
4640 |
png_uint_32 row_width=row_info->width;
|
|
|
4641 |
|
|
10576
|
4642 |
png_debug(1, "in png_do_quantize");
|
|
|
4643 |
|
|
|
4644 |
if (row_info->bit_depth == 8)
|
|
2
|
4645 |
{
|
|
10576
|
4646 |
if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup)
|
|
2
|
4647 |
{
|
|
|
4648 |
int r, g, b, p;
|
|
|
4649 |
sp = row;
|
|
|
4650 |
dp = row;
|
|
|
4651 |
for (i = 0; i < row_width; i++)
|
|
|
4652 |
{
|
|
|
4653 |
r = *sp++;
|
|
|
4654 |
g = *sp++;
|
|
|
4655 |
b = *sp++;
|
|
|
4656 |
|
|
10576
|
4657 |
/* This looks real messy, but the compiler will reduce
|
|
|
4658 |
* it down to a reasonable formula. For example, with
|
|
|
4659 |
* 5 bits per color, we get:
|
|
|
4660 |
* p = (((r >> 3) & 0x1f) << 10) |
|
|
|
4661 |
* (((g >> 3) & 0x1f) << 5) |
|
|
|
4662 |
* ((b >> 3) & 0x1f);
|
|
|
4663 |
*/
|
|
|
4664 |
p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
|
|
|
4665 |
((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
|
|
|
4666 |
(PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
|
|
|
4667 |
(((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
|
|
|
4668 |
((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
|
|
|
4669 |
(PNG_QUANTIZE_BLUE_BITS)) |
|
|
|
4670 |
((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
|
|
|
4671 |
((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
|
|
2
|
4672 |
|
|
|
4673 |
*dp++ = palette_lookup[p];
|
|
|
4674 |
}
|
|
10576
|
4675 |
|
|
2
|
4676 |
row_info->color_type = PNG_COLOR_TYPE_PALETTE;
|
|
|
4677 |
row_info->channels = 1;
|
|
|
4678 |
row_info->pixel_depth = row_info->bit_depth;
|
|
10576
|
4679 |
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
|
2
|
4680 |
}
|
|
10576
|
4681 |
|
|
2
|
4682 |
else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
|
|
10576
|
4683 |
palette_lookup != NULL)
|
|
2
|
4684 |
{
|
|
|
4685 |
int r, g, b, p;
|
|
|
4686 |
sp = row;
|
|
|
4687 |
dp = row;
|
|
|
4688 |
for (i = 0; i < row_width; i++)
|
|
|
4689 |
{
|
|
|
4690 |
r = *sp++;
|
|
|
4691 |
g = *sp++;
|
|
|
4692 |
b = *sp++;
|
|
|
4693 |
sp++;
|
|
|
4694 |
|
|
10576
|
4695 |
p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
|
|
|
4696 |
((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
|
|
|
4697 |
(PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
|
|
|
4698 |
(((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
|
|
|
4699 |
((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
|
|
|
4700 |
(PNG_QUANTIZE_BLUE_BITS)) |
|
|
|
4701 |
((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
|
|
|
4702 |
((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
|
|
2
|
4703 |
|
|
|
4704 |
*dp++ = palette_lookup[p];
|
|
|
4705 |
}
|
|
10576
|
4706 |
|
|
2
|
4707 |
row_info->color_type = PNG_COLOR_TYPE_PALETTE;
|
|
|
4708 |
row_info->channels = 1;
|
|
|
4709 |
row_info->pixel_depth = row_info->bit_depth;
|
|
10576
|
4710 |
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
|
2
|
4711 |
}
|
|
10576
|
4712 |
|
|
2
|
4713 |
else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
|
|
10576
|
4714 |
quantize_lookup)
|
|
2
|
4715 |
{
|
|
|
4716 |
sp = row;
|
|
10576
|
4717 |
|
|
2
|
4718 |
for (i = 0; i < row_width; i++, sp++)
|
|
|
4719 |
{
|
|
10576
|
4720 |
*sp = quantize_lookup[*sp];
|
|
2
|
4721 |
}
|
|
|
4722 |
}
|
|
|
4723 |
}
|
|
|
4724 |
}
|
|
29913
|
4725 |
#endif /* READ_QUANTIZE */
|
|
|
4726 |
|
|
|
4727 |
/* Transform the row. The order of transformations is significant,
|
|
|
4728 |
* and is very touchy. If you add a transformation, take care to
|
|
|
4729 |
* decide how it fits in with the other transformations here.
|
|
|
4730 |
*/
|
|
2
|
4731 |
void /* PRIVATE */
|
|
29913
|
4732 |
png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
|
|
2
|
4733 |
{
|
|
29913
|
4734 |
png_debug(1, "in png_do_read_transformations");
|
|
|
4735 |
|
|
|
4736 |
if (png_ptr->row_buf == NULL)
|
|
2
|
4737 |
{
|
|
29913
|
4738 |
/* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this
|
|
|
4739 |
* error is incredibly rare and incredibly easy to debug without this
|
|
|
4740 |
* information.
|
|
|
4741 |
*/
|
|
|
4742 |
png_error(png_ptr, "NULL row buffer");
|
|
|
4743 |
}
|
|
|
4744 |
|
|
|
4745 |
/* The following is debugging; prior to 1.5.4 the code was never compiled in;
|
|
|
4746 |
* in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro
|
|
|
4747 |
* PNG_WARN_UNINITIALIZED_ROW removed. In 1.6 the new flag is set only for
|
|
|
4748 |
* all transformations, however in practice the ROW_INIT always gets done on
|
|
|
4749 |
* demand, if necessary.
|
|
|
4750 |
*/
|
|
|
4751 |
if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 &&
|
|
|
4752 |
(png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
|
|
|
4753 |
{
|
|
|
4754 |
/* Application has failed to call either png_read_start_image() or
|
|
|
4755 |
* png_read_update_info() after setting transforms that expand pixels.
|
|
|
4756 |
* This check added to libpng-1.2.19 (but not enabled until 1.5.4).
|
|
|
4757 |
*/
|
|
|
4758 |
png_error(png_ptr, "Uninitialized row");
|
|
|
4759 |
}
|
|
|
4760 |
|
|
|
4761 |
#ifdef PNG_READ_EXPAND_SUPPORTED
|
|
|
4762 |
if ((png_ptr->transformations & PNG_EXPAND) != 0)
|
|
|
4763 |
{
|
|
|
4764 |
if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
2
|
4765 |
{
|
|
29913
|
4766 |
png_do_expand_palette(row_info, png_ptr->row_buf + 1,
|
|
|
4767 |
png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans);
|
|
|
4768 |
}
|
|
|
4769 |
|
|
|
4770 |
else
|
|
|
4771 |
{
|
|
|
4772 |
if (png_ptr->num_trans != 0 &&
|
|
|
4773 |
(png_ptr->transformations & PNG_EXPAND_tRNS) != 0)
|
|
|
4774 |
png_do_expand(row_info, png_ptr->row_buf + 1,
|
|
|
4775 |
&(png_ptr->trans_color));
|
|
10576
|
4776 |
|
|
2
|
4777 |
else
|
|
29913
|
4778 |
png_do_expand(row_info, png_ptr->row_buf + 1,
|
|
|
4779 |
NULL);
|
|
2
|
4780 |
}
|
|
29913
|
4781 |
}
|
|
|
4782 |
#endif
|
|
|
4783 |
|
|
|
4784 |
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
|
|
|
4785 |
if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
|
|
|
4786 |
(png_ptr->transformations & PNG_COMPOSE) == 0 &&
|
|
|
4787 |
(row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
|
|
|
4788 |
row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
|
|
|
4789 |
png_do_strip_channel(row_info, png_ptr->row_buf + 1,
|
|
|
4790 |
0 /* at_start == false, because SWAP_ALPHA happens later */);
|
|
|
4791 |
#endif
|
|
|
4792 |
|
|
|
4793 |
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
|
|
4794 |
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
|
|
|
4795 |
{
|
|
|
4796 |
int rgb_error =
|
|
|
4797 |
png_do_rgb_to_gray(png_ptr, row_info,
|
|
|
4798 |
png_ptr->row_buf + 1);
|
|
|
4799 |
|
|
|
4800 |
if (rgb_error != 0)
|
|
2
|
4801 |
{
|
|
29913
|
4802 |
png_ptr->rgb_to_gray_status=1;
|
|
|
4803 |
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
|
|
|
4804 |
PNG_RGB_TO_GRAY_WARN)
|
|
|
4805 |
png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
|
|
|
4806 |
|
|
|
4807 |
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
|
|
|
4808 |
PNG_RGB_TO_GRAY_ERR)
|
|
|
4809 |
png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
|
|
2
|
4810 |
}
|
|
|
4811 |
}
|
|
29913
|
4812 |
#endif
|
|
|
4813 |
|
|
|
4814 |
/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
|
|
|
4815 |
*
|
|
|
4816 |
* In most cases, the "simple transparency" should be done prior to doing
|
|
|
4817 |
* gray-to-RGB, or you will have to test 3x as many bytes to check if a
|
|
|
4818 |
* pixel is transparent. You would also need to make sure that the
|
|
|
4819 |
* transparency information is upgraded to RGB.
|
|
|
4820 |
*
|
|
|
4821 |
* To summarize, the current flow is:
|
|
|
4822 |
* - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
|
|
|
4823 |
* with background "in place" if transparent,
|
|
|
4824 |
* convert to RGB if necessary
|
|
|
4825 |
* - Gray + alpha -> composite with gray background and remove alpha bytes,
|
|
|
4826 |
* convert to RGB if necessary
|
|
|
4827 |
*
|
|
|
4828 |
* To support RGB backgrounds for gray images we need:
|
|
|
4829 |
* - Gray + simple transparency -> convert to RGB + simple transparency,
|
|
|
4830 |
* compare 3 or 6 bytes and composite with
|
|
|
4831 |
* background "in place" if transparent
|
|
|
4832 |
* (3x compare/pixel compared to doing
|
|
|
4833 |
* composite with gray bkgrnd)
|
|
|
4834 |
* - Gray + alpha -> convert to RGB + alpha, composite with background and
|
|
|
4835 |
* remove alpha bytes (3x float
|
|
|
4836 |
* operations/pixel compared with composite
|
|
|
4837 |
* on gray background)
|
|
|
4838 |
*
|
|
|
4839 |
* Greg's change will do this. The reason it wasn't done before is for
|
|
|
4840 |
* performance, as this increases the per-pixel operations. If we would check
|
|
|
4841 |
* in advance if the background was gray or RGB, and position the gray-to-RGB
|
|
|
4842 |
* transform appropriately, then it would save a lot of work/time.
|
|
|
4843 |
*/
|
|
|
4844 |
|
|
|
4845 |
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
|
|
4846 |
/* If gray -> RGB, do so now only if background is non-gray; else do later
|
|
|
4847 |
* for performance reasons
|
|
|
4848 |
*/
|
|
|
4849 |
if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 &&
|
|
|
4850 |
(png_ptr->mode & PNG_BACKGROUND_IS_GRAY) == 0)
|
|
|
4851 |
png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
|
|
|
4852 |
#endif
|
|
|
4853 |
|
|
|
4854 |
#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
|
|
|
4855 |
defined(PNG_READ_ALPHA_MODE_SUPPORTED)
|
|
|
4856 |
if ((png_ptr->transformations & PNG_COMPOSE) != 0)
|
|
|
4857 |
png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr);
|
|
|
4858 |
#endif
|
|
|
4859 |
|
|
|
4860 |
#ifdef PNG_READ_GAMMA_SUPPORTED
|
|
|
4861 |
if ((png_ptr->transformations & PNG_GAMMA) != 0 &&
|
|
|
4862 |
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
|
|
4863 |
/* Because RGB_TO_GRAY does the gamma transform. */
|
|
|
4864 |
(png_ptr->transformations & PNG_RGB_TO_GRAY) == 0 &&
|
|
|
4865 |
#endif
|
|
|
4866 |
#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
|
|
|
4867 |
defined(PNG_READ_ALPHA_MODE_SUPPORTED)
|
|
|
4868 |
/* Because PNG_COMPOSE does the gamma transform if there is something to
|
|
|
4869 |
* do (if there is an alpha channel or transparency.)
|
|
|
4870 |
*/
|
|
35296
|
4871 |
!((png_ptr->transformations & PNG_COMPOSE) != 0 &&
|
|
29913
|
4872 |
((png_ptr->num_trans != 0) ||
|
|
|
4873 |
(png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)) &&
|
|
|
4874 |
#endif
|
|
|
4875 |
/* Because png_init_read_transformations transforms the palette, unless
|
|
|
4876 |
* RGB_TO_GRAY will do the transform.
|
|
|
4877 |
*/
|
|
|
4878 |
(png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
|
|
|
4879 |
png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr);
|
|
|
4880 |
#endif
|
|
|
4881 |
|
|
|
4882 |
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
|
|
|
4883 |
if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
|
|
|
4884 |
(png_ptr->transformations & PNG_COMPOSE) != 0 &&
|
|
|
4885 |
(row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
|
|
|
4886 |
row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
|
|
|
4887 |
png_do_strip_channel(row_info, png_ptr->row_buf + 1,
|
|
|
4888 |
0 /* at_start == false, because SWAP_ALPHA happens later */);
|
|
|
4889 |
#endif
|
|
|
4890 |
|
|
|
4891 |
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
|
|
|
4892 |
if ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 &&
|
|
|
4893 |
(row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
|
|
|
4894 |
png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr);
|
|
|
4895 |
#endif
|
|
|
4896 |
|
|
|
4897 |
#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
|
|
|
4898 |
if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0)
|
|
|
4899 |
png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1);
|
|
|
4900 |
#endif
|
|
|
4901 |
|
|
|
4902 |
#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
|
|
|
4903 |
/* There is no harm in doing both of these because only one has any effect,
|
|
|
4904 |
* by putting the 'scale' option first if the app asks for scale (either by
|
|
|
4905 |
* calling the API or in a TRANSFORM flag) this is what happens.
|
|
|
4906 |
*/
|
|
|
4907 |
if ((png_ptr->transformations & PNG_16_TO_8) != 0)
|
|
|
4908 |
png_do_chop(row_info, png_ptr->row_buf + 1);
|
|
|
4909 |
#endif
|
|
|
4910 |
|
|
|
4911 |
#ifdef PNG_READ_QUANTIZE_SUPPORTED
|
|
|
4912 |
if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
|
|
|
4913 |
{
|
|
|
4914 |
png_do_quantize(row_info, png_ptr->row_buf + 1,
|
|
|
4915 |
png_ptr->palette_lookup, png_ptr->quantize_index);
|
|
|
4916 |
|
|
|
4917 |
if (row_info->rowbytes == 0)
|
|
|
4918 |
png_error(png_ptr, "png_do_quantize returned rowbytes=0");
|
|
|
4919 |
}
|
|
|
4920 |
#endif /* READ_QUANTIZE */
|
|
|
4921 |
|
|
|
4922 |
#ifdef PNG_READ_EXPAND_16_SUPPORTED
|
|
|
4923 |
/* Do the expansion now, after all the arithmetic has been done. Notice
|
|
|
4924 |
* that previous transformations can handle the PNG_EXPAND_16 flag if this
|
|
|
4925 |
* is efficient (particularly true in the case of gamma correction, where
|
|
|
4926 |
* better accuracy results faster!)
|
|
|
4927 |
*/
|
|
|
4928 |
if ((png_ptr->transformations & PNG_EXPAND_16) != 0)
|
|
|
4929 |
png_do_expand_16(row_info, png_ptr->row_buf + 1);
|
|
|
4930 |
#endif
|
|
|
4931 |
|
|
|
4932 |
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
|
|
4933 |
/* NOTE: moved here in 1.5.4 (from much later in this list.) */
|
|
|
4934 |
if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 &&
|
|
|
4935 |
(png_ptr->mode & PNG_BACKGROUND_IS_GRAY) != 0)
|
|
|
4936 |
png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
|
|
|
4937 |
#endif
|
|
|
4938 |
|
|
|
4939 |
#ifdef PNG_READ_INVERT_SUPPORTED
|
|
|
4940 |
if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
|
|
|
4941 |
png_do_invert(row_info, png_ptr->row_buf + 1);
|
|
|
4942 |
#endif
|
|
|
4943 |
|
|
|
4944 |
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
|
|
|
4945 |
if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
|
|
|
4946 |
png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1);
|
|
|
4947 |
#endif
|
|
|
4948 |
|
|
|
4949 |
#ifdef PNG_READ_SHIFT_SUPPORTED
|
|
|
4950 |
if ((png_ptr->transformations & PNG_SHIFT) != 0)
|
|
|
4951 |
png_do_unshift(row_info, png_ptr->row_buf + 1,
|
|
|
4952 |
&(png_ptr->shift));
|
|
|
4953 |
#endif
|
|
|
4954 |
|
|
|
4955 |
#ifdef PNG_READ_PACK_SUPPORTED
|
|
|
4956 |
if ((png_ptr->transformations & PNG_PACK) != 0)
|
|
|
4957 |
png_do_unpack(row_info, png_ptr->row_buf + 1);
|
|
|
4958 |
#endif
|
|
|
4959 |
|
|
|
4960 |
#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
|
|
|
4961 |
/* Added at libpng-1.5.10 */
|
|
|
4962 |
if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
|
|
|
4963 |
png_ptr->num_palette_max >= 0)
|
|
|
4964 |
png_do_check_palette_indexes(png_ptr, row_info);
|
|
|
4965 |
#endif
|
|
|
4966 |
|
|
|
4967 |
#ifdef PNG_READ_BGR_SUPPORTED
|
|
|
4968 |
if ((png_ptr->transformations & PNG_BGR) != 0)
|
|
|
4969 |
png_do_bgr(row_info, png_ptr->row_buf + 1);
|
|
|
4970 |
#endif
|
|
|
4971 |
|
|
|
4972 |
#ifdef PNG_READ_PACKSWAP_SUPPORTED
|
|
|
4973 |
if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
|
|
|
4974 |
png_do_packswap(row_info, png_ptr->row_buf + 1);
|
|
|
4975 |
#endif
|
|
|
4976 |
|
|
|
4977 |
#ifdef PNG_READ_FILLER_SUPPORTED
|
|
|
4978 |
if ((png_ptr->transformations & PNG_FILLER) != 0)
|
|
|
4979 |
png_do_read_filler(row_info, png_ptr->row_buf + 1,
|
|
|
4980 |
(png_uint_32)png_ptr->filler, png_ptr->flags);
|
|
|
4981 |
#endif
|
|
|
4982 |
|
|
|
4983 |
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
|
|
|
4984 |
if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
|
|
|
4985 |
png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1);
|
|
|
4986 |
#endif
|
|
|
4987 |
|
|
|
4988 |
#ifdef PNG_READ_16BIT_SUPPORTED
|
|
|
4989 |
#ifdef PNG_READ_SWAP_SUPPORTED
|
|
|
4990 |
if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
|
|
|
4991 |
png_do_swap(row_info, png_ptr->row_buf + 1);
|
|
|
4992 |
#endif
|
|
|
4993 |
#endif
|
|
|
4994 |
|
|
|
4995 |
#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
|
|
|
4996 |
if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
|
|
|
4997 |
{
|
|
|
4998 |
if (png_ptr->read_user_transform_fn != NULL)
|
|
|
4999 |
(*(png_ptr->read_user_transform_fn)) /* User read transform function */
|
|
|
5000 |
(png_ptr, /* png_ptr */
|
|
|
5001 |
row_info, /* row_info: */
|
|
|
5002 |
/* png_uint_32 width; width of row */
|
|
|
5003 |
/* png_size_t rowbytes; number of bytes in row */
|
|
|
5004 |
/* png_byte color_type; color type of pixels */
|
|
|
5005 |
/* png_byte bit_depth; bit depth of samples */
|
|
|
5006 |
/* png_byte channels; number of channels (1-4) */
|
|
|
5007 |
/* png_byte pixel_depth; bits per pixel (depth*channels) */
|
|
|
5008 |
png_ptr->row_buf + 1); /* start of pixel data for row */
|
|
|
5009 |
#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
|
|
|
5010 |
if (png_ptr->user_transform_depth != 0)
|
|
|
5011 |
row_info->bit_depth = png_ptr->user_transform_depth;
|
|
|
5012 |
|
|
|
5013 |
if (png_ptr->user_transform_channels != 0)
|
|
|
5014 |
row_info->channels = png_ptr->user_transform_channels;
|
|
|
5015 |
#endif
|
|
|
5016 |
row_info->pixel_depth = (png_byte)(row_info->bit_depth *
|
|
|
5017 |
row_info->channels);
|
|
|
5018 |
|
|
|
5019 |
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width);
|
|
|
5020 |
}
|
|
|
5021 |
#endif
|
|
2
|
5022 |
}
|
|
29913
|
5023 |
|
|
|
5024 |
#endif /* READ_TRANSFORMS */
|
|
|
5025 |
#endif /* READ */
|