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1 /* |
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2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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3 * |
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4 * This code is free software; you can redistribute it and/or modify it |
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5 * under the terms of the GNU General Public License version 2 only, as |
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6 * published by the Free Software Foundation. Oracle designates this |
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7 * particular file as subject to the "Classpath" exception as provided |
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8 * by Oracle in the LICENSE file that accompanied this code. |
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9 * |
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10 * This code is distributed in the hope that it will be useful, but WITHOUT |
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11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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13 * version 2 for more details (a copy is included in the LICENSE file that |
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14 * accompanied this code). |
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15 * |
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16 * You should have received a copy of the GNU General Public License version |
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17 * 2 along with this work; if not, write to the Free Software Foundation, |
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18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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19 * |
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20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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21 * or visit www.oracle.com if you need additional information or have any |
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22 * questions. |
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23 */ |
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24 |
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25 /* pngrtran.c - transforms the data in a row for PNG readers |
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26 * |
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27 * This file is available under and governed by the GNU General Public |
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28 * License version 2 only, as published by the Free Software Foundation. |
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29 * However, the following notice accompanied the original version of this |
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30 * file and, per its terms, should not be removed: |
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31 * |
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32 * Last changed in libpng 1.5.4 [July 7, 2011] |
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33 * Copyright (c) 1998-2011 Glenn Randers-Pehrson |
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34 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
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35 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
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36 * |
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37 * This code is released under the libpng license. |
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38 * For conditions of distribution and use, see the disclaimer |
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39 * and license in png.h |
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40 * |
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41 * This file contains functions optionally called by an application |
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42 * in order to tell libpng how to handle data when reading a PNG. |
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43 * Transformations that are used in both reading and writing are |
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44 * in pngtrans.c. |
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45 */ |
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46 |
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47 #include "pngpriv.h" |
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48 |
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49 #ifdef PNG_READ_SUPPORTED |
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50 |
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51 /* Set the action on getting a CRC error for an ancillary or critical chunk. */ |
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52 void PNGAPI |
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53 png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) |
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54 { |
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55 png_debug(1, "in png_set_crc_action"); |
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56 |
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57 if (png_ptr == NULL) |
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58 return; |
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59 |
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60 /* Tell libpng how we react to CRC errors in critical chunks */ |
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61 switch (crit_action) |
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62 { |
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63 case PNG_CRC_NO_CHANGE: /* Leave setting as is */ |
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64 break; |
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65 |
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66 case PNG_CRC_WARN_USE: /* Warn/use data */ |
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67 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
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68 png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; |
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69 break; |
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70 |
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71 case PNG_CRC_QUIET_USE: /* Quiet/use data */ |
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72 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
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73 png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | |
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74 PNG_FLAG_CRC_CRITICAL_IGNORE; |
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75 break; |
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76 |
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77 case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */ |
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78 png_warning(png_ptr, |
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79 "Can't discard critical data on CRC error"); |
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80 case PNG_CRC_ERROR_QUIT: /* Error/quit */ |
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81 |
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82 case PNG_CRC_DEFAULT: |
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83 default: |
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84 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
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85 break; |
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86 } |
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87 |
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88 /* Tell libpng how we react to CRC errors in ancillary chunks */ |
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89 switch (ancil_action) |
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90 { |
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91 case PNG_CRC_NO_CHANGE: /* Leave setting as is */ |
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92 break; |
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93 |
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94 case PNG_CRC_WARN_USE: /* Warn/use data */ |
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95 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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96 png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; |
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97 break; |
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98 |
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99 case PNG_CRC_QUIET_USE: /* Quiet/use data */ |
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100 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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101 png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | |
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102 PNG_FLAG_CRC_ANCILLARY_NOWARN; |
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103 break; |
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104 |
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105 case PNG_CRC_ERROR_QUIT: /* Error/quit */ |
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106 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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107 png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; |
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108 break; |
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109 |
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110 case PNG_CRC_WARN_DISCARD: /* Warn/discard data */ |
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111 |
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112 case PNG_CRC_DEFAULT: |
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113 default: |
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114 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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115 break; |
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116 } |
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117 } |
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118 |
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119 #ifdef PNG_READ_BACKGROUND_SUPPORTED |
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120 /* Handle alpha and tRNS via a background color */ |
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121 void PNGFAPI |
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122 png_set_background_fixed(png_structp png_ptr, |
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123 png_const_color_16p background_color, int background_gamma_code, |
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124 int need_expand, png_fixed_point background_gamma) |
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125 { |
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126 png_debug(1, "in png_set_background_fixed"); |
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127 |
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128 if (png_ptr == NULL) |
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129 return; |
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130 |
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131 if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) |
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132 { |
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133 png_warning(png_ptr, "Application must supply a known background gamma"); |
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134 return; |
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135 } |
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136 |
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137 png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA; |
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138 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
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139 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
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140 |
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141 png_memcpy(&(png_ptr->background), background_color, |
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142 png_sizeof(png_color_16)); |
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143 png_ptr->background_gamma = background_gamma; |
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144 png_ptr->background_gamma_type = (png_byte)(background_gamma_code); |
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145 if (need_expand) |
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146 png_ptr->transformations |= PNG_BACKGROUND_EXPAND; |
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147 else |
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148 png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; |
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149 } |
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150 |
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151 # ifdef PNG_FLOATING_POINT_SUPPORTED |
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152 void PNGAPI |
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153 png_set_background(png_structp png_ptr, |
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154 png_const_color_16p background_color, int background_gamma_code, |
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155 int need_expand, double background_gamma) |
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156 { |
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157 png_set_background_fixed(png_ptr, background_color, background_gamma_code, |
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158 need_expand, png_fixed(png_ptr, background_gamma, "png_set_background")); |
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159 } |
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160 # endif /* FLOATING_POINT */ |
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161 #endif /* READ_BACKGROUND */ |
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162 |
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163 /* Scale 16-bit depth files to 8-bit depth. If both of these are set then the |
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164 * one that pngrtran does first (scale) happens. This is necessary to allow the |
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165 * TRANSFORM and API behavior to be somewhat consistent, and it's simpler. |
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166 */ |
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167 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED |
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168 void PNGAPI |
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169 png_set_scale_16(png_structp png_ptr) |
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170 { |
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171 png_debug(1, "in png_set_scale_16"); |
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172 |
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173 if (png_ptr == NULL) |
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174 return; |
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175 |
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176 png_ptr->transformations |= PNG_SCALE_16_TO_8; |
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177 } |
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178 #endif |
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179 |
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180 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED |
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181 /* Chop 16-bit depth files to 8-bit depth */ |
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182 void PNGAPI |
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183 png_set_strip_16(png_structp png_ptr) |
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184 { |
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185 png_debug(1, "in png_set_strip_16"); |
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186 |
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187 if (png_ptr == NULL) |
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188 return; |
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189 |
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190 png_ptr->transformations |= PNG_16_TO_8; |
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191 } |
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192 #endif |
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193 |
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194 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
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195 void PNGAPI |
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196 png_set_strip_alpha(png_structp png_ptr) |
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197 { |
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198 png_debug(1, "in png_set_strip_alpha"); |
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199 |
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200 if (png_ptr == NULL) |
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201 return; |
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202 |
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203 png_ptr->transformations |= PNG_STRIP_ALPHA; |
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204 } |
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205 #endif |
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206 |
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207 #if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED) |
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208 static png_fixed_point |
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209 translate_gamma_flags(png_structp png_ptr, png_fixed_point output_gamma, |
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210 int is_screen) |
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211 { |
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212 /* Check for flag values. The main reason for having the old Mac value as a |
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213 * flag is that it is pretty near impossible to work out what the correct |
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214 * value is from Apple documentation - a working Mac system is needed to |
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215 * discover the value! |
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216 */ |
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217 if (output_gamma == PNG_DEFAULT_sRGB || |
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218 output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB) |
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219 { |
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220 /* If there is no sRGB support this just sets the gamma to the standard |
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221 * sRGB value. (This is a side effect of using this function!) |
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222 */ |
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223 # ifdef PNG_READ_sRGB_SUPPORTED |
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224 png_ptr->flags |= PNG_FLAG_ASSUME_sRGB; |
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225 # endif |
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226 if (is_screen) |
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227 output_gamma = PNG_GAMMA_sRGB; |
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228 else |
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229 output_gamma = PNG_GAMMA_sRGB_INVERSE; |
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230 } |
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231 |
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232 else if (output_gamma == PNG_GAMMA_MAC_18 || |
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233 output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18) |
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234 { |
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235 if (is_screen) |
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236 output_gamma = PNG_GAMMA_MAC_OLD; |
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237 else |
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238 output_gamma = PNG_GAMMA_MAC_INVERSE; |
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239 } |
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240 |
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241 return output_gamma; |
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242 } |
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243 |
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244 # ifdef PNG_FLOATING_POINT_SUPPORTED |
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245 static png_fixed_point |
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246 convert_gamma_value(png_structp png_ptr, double output_gamma) |
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247 { |
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248 /* The following silently ignores cases where fixed point (times 100,000) |
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249 * gamma values are passed to the floating point API. This is safe and it |
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250 * means the fixed point constants work just fine with the floating point |
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251 * API. The alternative would just lead to undetected errors and spurious |
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252 * bug reports. Negative values fail inside the _fixed API unless they |
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253 * correspond to the flag values. |
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254 */ |
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255 if (output_gamma > 0 && output_gamma < 128) |
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256 output_gamma *= PNG_FP_1; |
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257 |
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258 /* This preserves -1 and -2 exactly: */ |
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259 output_gamma = floor(output_gamma + .5); |
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260 |
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261 if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN) |
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262 png_fixed_error(png_ptr, "gamma value"); |
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263 |
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264 return (png_fixed_point)output_gamma; |
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265 } |
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266 # endif |
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267 #endif /* READ_ALPHA_MODE || READ_GAMMA */ |
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268 |
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269 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
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270 void PNGFAPI |
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271 png_set_alpha_mode_fixed(png_structp png_ptr, int mode, |
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272 png_fixed_point output_gamma) |
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273 { |
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274 int compose = 0; |
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275 png_fixed_point file_gamma; |
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276 |
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277 png_debug(1, "in png_set_alpha_mode"); |
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278 |
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279 if (png_ptr == NULL) |
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280 return; |
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281 |
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282 output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/); |
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283 |
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284 /* Validate the value to ensure it is in a reasonable range. The value |
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285 * is expected to be 1 or greater, but this range test allows for some |
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286 * viewing correction values. The intent is to weed out users of this API |
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287 * who use the inverse of the gamma value accidentally! Since some of these |
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288 * values are reasonable this may have to be changed. |
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289 */ |
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290 if (output_gamma < 70000 || output_gamma > 300000) |
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291 png_error(png_ptr, "output gamma out of expected range"); |
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292 |
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293 /* The default file gamma is the inverse of the output gamma; the output |
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294 * gamma may be changed below so get the file value first: |
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295 */ |
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296 file_gamma = png_reciprocal(output_gamma); |
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297 |
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298 /* There are really 8 possibilities here, composed of any combination |
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299 * of: |
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300 * |
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301 * premultiply the color channels |
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302 * do not encode non-opaque pixels |
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303 * encode the alpha as well as the color channels |
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304 * |
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305 * The differences disappear if the input/output ('screen') gamma is 1.0, |
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306 * because then the encoding is a no-op and there is only the choice of |
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307 * premultiplying the color channels or not. |
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308 * |
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309 * png_set_alpha_mode and png_set_background interact because both use |
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310 * png_compose to do the work. Calling both is only useful when |
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311 * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along |
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312 * with a default gamma value. Otherwise PNG_COMPOSE must not be set. |
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313 */ |
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314 switch (mode) |
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315 { |
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316 case PNG_ALPHA_PNG: /* default: png standard */ |
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317 /* No compose, but it may be set by png_set_background! */ |
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318 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
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319 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
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320 break; |
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321 |
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322 case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */ |
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323 compose = 1; |
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324 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
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325 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
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326 /* The output is linear: */ |
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327 output_gamma = PNG_FP_1; |
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328 break; |
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329 |
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330 case PNG_ALPHA_OPTIMIZED: /* associated, non-opaque pixels linear */ |
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331 compose = 1; |
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332 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
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333 png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA; |
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334 /* output_gamma records the encoding of opaque pixels! */ |
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335 break; |
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336 |
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337 case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */ |
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338 compose = 1; |
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339 png_ptr->transformations |= PNG_ENCODE_ALPHA; |
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340 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
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341 break; |
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342 |
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343 default: |
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344 png_error(png_ptr, "invalid alpha mode"); |
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345 } |
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346 |
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347 /* Only set the default gamma if the file gamma has not been set (this has |
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348 * the side effect that the gamma in a second call to png_set_alpha_mode will |
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349 * be ignored.) |
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350 */ |
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351 if (png_ptr->gamma == 0) |
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352 png_ptr->gamma = file_gamma; |
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353 |
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354 /* But always set the output gamma: */ |
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355 png_ptr->screen_gamma = output_gamma; |
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356 |
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357 /* Finally, if pre-multiplying, set the background fields to achieve the |
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358 * desired result. |
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359 */ |
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360 if (compose) |
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361 { |
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362 /* And obtain alpha pre-multiplication by composing on black: */ |
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363 png_memset(&png_ptr->background, 0, sizeof png_ptr->background); |
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364 png_ptr->background_gamma = png_ptr->gamma; /* just in case */ |
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365 png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE; |
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366 png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; |
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367 |
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368 if (png_ptr->transformations & PNG_COMPOSE) |
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369 png_error(png_ptr, |
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370 "conflicting calls to set alpha mode and background"); |
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371 |
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372 png_ptr->transformations |= PNG_COMPOSE; |
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373 } |
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374 |
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375 /* New API, make sure apps call the correct initializers: */ |
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376 png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED; |
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377 } |
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378 |
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379 # ifdef PNG_FLOATING_POINT_SUPPORTED |
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380 void PNGAPI |
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381 png_set_alpha_mode(png_structp png_ptr, int mode, double output_gamma) |
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382 { |
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383 png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr, |
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384 output_gamma)); |
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385 } |
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386 # endif |
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387 #endif |
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388 |
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389 #ifdef PNG_READ_QUANTIZE_SUPPORTED |
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390 /* Dither file to 8-bit. Supply a palette, the current number |
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391 * of elements in the palette, the maximum number of elements |
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392 * allowed, and a histogram if possible. If the current number |
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393 * of colors is greater then the maximum number, the palette will be |
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394 * modified to fit in the maximum number. "full_quantize" indicates |
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395 * whether we need a quantizing cube set up for RGB images, or if we |
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396 * simply are reducing the number of colors in a paletted image. |
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397 */ |
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398 |
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399 typedef struct png_dsort_struct |
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400 { |
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401 struct png_dsort_struct FAR * next; |
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402 png_byte left; |
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403 png_byte right; |
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404 } png_dsort; |
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405 typedef png_dsort FAR * png_dsortp; |
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406 typedef png_dsort FAR * FAR * png_dsortpp; |
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407 |
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408 void PNGAPI |
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409 png_set_quantize(png_structp png_ptr, png_colorp palette, |
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410 int num_palette, int maximum_colors, png_const_uint_16p histogram, |
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411 int full_quantize) |
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412 { |
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413 png_debug(1, "in png_set_quantize"); |
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414 |
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415 if (png_ptr == NULL) |
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416 return; |
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417 |
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418 png_ptr->transformations |= PNG_QUANTIZE; |
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419 |
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420 if (!full_quantize) |
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421 { |
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422 int i; |
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423 |
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424 png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr, |
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425 (png_uint_32)(num_palette * png_sizeof(png_byte))); |
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426 for (i = 0; i < num_palette; i++) |
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427 png_ptr->quantize_index[i] = (png_byte)i; |
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428 } |
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429 |
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430 if (num_palette > maximum_colors) |
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431 { |
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432 if (histogram != NULL) |
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433 { |
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434 /* This is easy enough, just throw out the least used colors. |
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435 * Perhaps not the best solution, but good enough. |
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436 */ |
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437 |
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438 int i; |
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439 |
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440 /* Initialize an array to sort colors */ |
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441 png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr, |
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442 (png_uint_32)(num_palette * png_sizeof(png_byte))); |
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443 |
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444 /* Initialize the quantize_sort array */ |
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445 for (i = 0; i < num_palette; i++) |
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446 png_ptr->quantize_sort[i] = (png_byte)i; |
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447 |
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448 /* Find the least used palette entries by starting a |
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449 * bubble sort, and running it until we have sorted |
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450 * out enough colors. Note that we don't care about |
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451 * sorting all the colors, just finding which are |
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452 * least used. |
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453 */ |
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454 |
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455 for (i = num_palette - 1; i >= maximum_colors; i--) |
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456 { |
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457 int done; /* To stop early if the list is pre-sorted */ |
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458 int j; |
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459 |
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460 done = 1; |
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461 for (j = 0; j < i; j++) |
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462 { |
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463 if (histogram[png_ptr->quantize_sort[j]] |
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464 < histogram[png_ptr->quantize_sort[j + 1]]) |
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465 { |
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466 png_byte t; |
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467 |
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468 t = png_ptr->quantize_sort[j]; |
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469 png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1]; |
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470 png_ptr->quantize_sort[j + 1] = t; |
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471 done = 0; |
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472 } |
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473 } |
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474 |
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475 if (done) |
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476 break; |
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477 } |
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478 |
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479 /* Swap the palette around, and set up a table, if necessary */ |
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480 if (full_quantize) |
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481 { |
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482 int j = num_palette; |
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483 |
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484 /* Put all the useful colors within the max, but don't |
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485 * move the others. |
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486 */ |
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487 for (i = 0; i < maximum_colors; i++) |
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488 { |
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489 if ((int)png_ptr->quantize_sort[i] >= maximum_colors) |
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490 { |
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491 do |
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492 j--; |
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493 while ((int)png_ptr->quantize_sort[j] >= maximum_colors); |
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494 |
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495 palette[i] = palette[j]; |
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496 } |
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497 } |
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498 } |
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499 else |
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500 { |
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501 int j = num_palette; |
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502 |
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503 /* Move all the used colors inside the max limit, and |
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504 * develop a translation table. |
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505 */ |
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506 for (i = 0; i < maximum_colors; i++) |
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507 { |
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508 /* Only move the colors we need to */ |
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509 if ((int)png_ptr->quantize_sort[i] >= maximum_colors) |
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510 { |
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511 png_color tmp_color; |
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512 |
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513 do |
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514 j--; |
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515 while ((int)png_ptr->quantize_sort[j] >= maximum_colors); |
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516 |
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517 tmp_color = palette[j]; |
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518 palette[j] = palette[i]; |
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519 palette[i] = tmp_color; |
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520 /* Indicate where the color went */ |
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521 png_ptr->quantize_index[j] = (png_byte)i; |
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522 png_ptr->quantize_index[i] = (png_byte)j; |
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523 } |
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524 } |
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525 |
|
526 /* Find closest color for those colors we are not using */ |
|
527 for (i = 0; i < num_palette; i++) |
|
528 { |
|
529 if ((int)png_ptr->quantize_index[i] >= maximum_colors) |
|
530 { |
|
531 int min_d, k, min_k, d_index; |
|
532 |
|
533 /* Find the closest color to one we threw out */ |
|
534 d_index = png_ptr->quantize_index[i]; |
|
535 min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); |
|
536 for (k = 1, min_k = 0; k < maximum_colors; k++) |
|
537 { |
|
538 int d; |
|
539 |
|
540 d = PNG_COLOR_DIST(palette[d_index], palette[k]); |
|
541 |
|
542 if (d < min_d) |
|
543 { |
|
544 min_d = d; |
|
545 min_k = k; |
|
546 } |
|
547 } |
|
548 /* Point to closest color */ |
|
549 png_ptr->quantize_index[i] = (png_byte)min_k; |
|
550 } |
|
551 } |
|
552 } |
|
553 png_free(png_ptr, png_ptr->quantize_sort); |
|
554 png_ptr->quantize_sort = NULL; |
|
555 } |
|
556 else |
|
557 { |
|
558 /* This is much harder to do simply (and quickly). Perhaps |
|
559 * we need to go through a median cut routine, but those |
|
560 * don't always behave themselves with only a few colors |
|
561 * as input. So we will just find the closest two colors, |
|
562 * and throw out one of them (chosen somewhat randomly). |
|
563 * [We don't understand this at all, so if someone wants to |
|
564 * work on improving it, be our guest - AED, GRP] |
|
565 */ |
|
566 int i; |
|
567 int max_d; |
|
568 int num_new_palette; |
|
569 png_dsortp t; |
|
570 png_dsortpp hash; |
|
571 |
|
572 t = NULL; |
|
573 |
|
574 /* Initialize palette index arrays */ |
|
575 png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr, |
|
576 (png_uint_32)(num_palette * png_sizeof(png_byte))); |
|
577 png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr, |
|
578 (png_uint_32)(num_palette * png_sizeof(png_byte))); |
|
579 |
|
580 /* Initialize the sort array */ |
|
581 for (i = 0; i < num_palette; i++) |
|
582 { |
|
583 png_ptr->index_to_palette[i] = (png_byte)i; |
|
584 png_ptr->palette_to_index[i] = (png_byte)i; |
|
585 } |
|
586 |
|
587 hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 * |
|
588 png_sizeof(png_dsortp))); |
|
589 |
|
590 num_new_palette = num_palette; |
|
591 |
|
592 /* Initial wild guess at how far apart the farthest pixel |
|
593 * pair we will be eliminating will be. Larger |
|
594 * numbers mean more areas will be allocated, Smaller |
|
595 * numbers run the risk of not saving enough data, and |
|
596 * having to do this all over again. |
|
597 * |
|
598 * I have not done extensive checking on this number. |
|
599 */ |
|
600 max_d = 96; |
|
601 |
|
602 while (num_new_palette > maximum_colors) |
|
603 { |
|
604 for (i = 0; i < num_new_palette - 1; i++) |
|
605 { |
|
606 int j; |
|
607 |
|
608 for (j = i + 1; j < num_new_palette; j++) |
|
609 { |
|
610 int d; |
|
611 |
|
612 d = PNG_COLOR_DIST(palette[i], palette[j]); |
|
613 |
|
614 if (d <= max_d) |
|
615 { |
|
616 |
|
617 t = (png_dsortp)png_malloc_warn(png_ptr, |
|
618 (png_uint_32)(png_sizeof(png_dsort))); |
|
619 |
|
620 if (t == NULL) |
|
621 break; |
|
622 |
|
623 t->next = hash[d]; |
|
624 t->left = (png_byte)i; |
|
625 t->right = (png_byte)j; |
|
626 hash[d] = t; |
|
627 } |
|
628 } |
|
629 if (t == NULL) |
|
630 break; |
|
631 } |
|
632 |
|
633 if (t != NULL) |
|
634 for (i = 0; i <= max_d; i++) |
|
635 { |
|
636 if (hash[i] != NULL) |
|
637 { |
|
638 png_dsortp p; |
|
639 |
|
640 for (p = hash[i]; p; p = p->next) |
|
641 { |
|
642 if ((int)png_ptr->index_to_palette[p->left] |
|
643 < num_new_palette && |
|
644 (int)png_ptr->index_to_palette[p->right] |
|
645 < num_new_palette) |
|
646 { |
|
647 int j, next_j; |
|
648 |
|
649 if (num_new_palette & 0x01) |
|
650 { |
|
651 j = p->left; |
|
652 next_j = p->right; |
|
653 } |
|
654 else |
|
655 { |
|
656 j = p->right; |
|
657 next_j = p->left; |
|
658 } |
|
659 |
|
660 num_new_palette--; |
|
661 palette[png_ptr->index_to_palette[j]] |
|
662 = palette[num_new_palette]; |
|
663 if (!full_quantize) |
|
664 { |
|
665 int k; |
|
666 |
|
667 for (k = 0; k < num_palette; k++) |
|
668 { |
|
669 if (png_ptr->quantize_index[k] == |
|
670 png_ptr->index_to_palette[j]) |
|
671 png_ptr->quantize_index[k] = |
|
672 png_ptr->index_to_palette[next_j]; |
|
673 |
|
674 if ((int)png_ptr->quantize_index[k] == |
|
675 num_new_palette) |
|
676 png_ptr->quantize_index[k] = |
|
677 png_ptr->index_to_palette[j]; |
|
678 } |
|
679 } |
|
680 |
|
681 png_ptr->index_to_palette[png_ptr->palette_to_index |
|
682 [num_new_palette]] = png_ptr->index_to_palette[j]; |
|
683 |
|
684 png_ptr->palette_to_index[png_ptr->index_to_palette[j]] |
|
685 = png_ptr->palette_to_index[num_new_palette]; |
|
686 |
|
687 png_ptr->index_to_palette[j] = |
|
688 (png_byte)num_new_palette; |
|
689 |
|
690 png_ptr->palette_to_index[num_new_palette] = |
|
691 (png_byte)j; |
|
692 } |
|
693 if (num_new_palette <= maximum_colors) |
|
694 break; |
|
695 } |
|
696 if (num_new_palette <= maximum_colors) |
|
697 break; |
|
698 } |
|
699 } |
|
700 |
|
701 for (i = 0; i < 769; i++) |
|
702 { |
|
703 if (hash[i] != NULL) |
|
704 { |
|
705 png_dsortp p = hash[i]; |
|
706 while (p) |
|
707 { |
|
708 t = p->next; |
|
709 png_free(png_ptr, p); |
|
710 p = t; |
|
711 } |
|
712 } |
|
713 hash[i] = 0; |
|
714 } |
|
715 max_d += 96; |
|
716 } |
|
717 png_free(png_ptr, hash); |
|
718 png_free(png_ptr, png_ptr->palette_to_index); |
|
719 png_free(png_ptr, png_ptr->index_to_palette); |
|
720 png_ptr->palette_to_index = NULL; |
|
721 png_ptr->index_to_palette = NULL; |
|
722 } |
|
723 num_palette = maximum_colors; |
|
724 } |
|
725 if (png_ptr->palette == NULL) |
|
726 { |
|
727 png_ptr->palette = palette; |
|
728 } |
|
729 png_ptr->num_palette = (png_uint_16)num_palette; |
|
730 |
|
731 if (full_quantize) |
|
732 { |
|
733 int i; |
|
734 png_bytep distance; |
|
735 int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS + |
|
736 PNG_QUANTIZE_BLUE_BITS; |
|
737 int num_red = (1 << PNG_QUANTIZE_RED_BITS); |
|
738 int num_green = (1 << PNG_QUANTIZE_GREEN_BITS); |
|
739 int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS); |
|
740 png_size_t num_entries = ((png_size_t)1 << total_bits); |
|
741 |
|
742 png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr, |
|
743 (png_uint_32)(num_entries * png_sizeof(png_byte))); |
|
744 |
|
745 distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * |
|
746 png_sizeof(png_byte))); |
|
747 |
|
748 png_memset(distance, 0xff, num_entries * png_sizeof(png_byte)); |
|
749 |
|
750 for (i = 0; i < num_palette; i++) |
|
751 { |
|
752 int ir, ig, ib; |
|
753 int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS)); |
|
754 int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS)); |
|
755 int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS)); |
|
756 |
|
757 for (ir = 0; ir < num_red; ir++) |
|
758 { |
|
759 /* int dr = abs(ir - r); */ |
|
760 int dr = ((ir > r) ? ir - r : r - ir); |
|
761 int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS + |
|
762 PNG_QUANTIZE_GREEN_BITS)); |
|
763 |
|
764 for (ig = 0; ig < num_green; ig++) |
|
765 { |
|
766 /* int dg = abs(ig - g); */ |
|
767 int dg = ((ig > g) ? ig - g : g - ig); |
|
768 int dt = dr + dg; |
|
769 int dm = ((dr > dg) ? dr : dg); |
|
770 int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS); |
|
771 |
|
772 for (ib = 0; ib < num_blue; ib++) |
|
773 { |
|
774 int d_index = index_g | ib; |
|
775 /* int db = abs(ib - b); */ |
|
776 int db = ((ib > b) ? ib - b : b - ib); |
|
777 int dmax = ((dm > db) ? dm : db); |
|
778 int d = dmax + dt + db; |
|
779 |
|
780 if (d < (int)distance[d_index]) |
|
781 { |
|
782 distance[d_index] = (png_byte)d; |
|
783 png_ptr->palette_lookup[d_index] = (png_byte)i; |
|
784 } |
|
785 } |
|
786 } |
|
787 } |
|
788 } |
|
789 |
|
790 png_free(png_ptr, distance); |
|
791 } |
|
792 } |
|
793 #endif /* PNG_READ_QUANTIZE_SUPPORTED */ |
|
794 |
|
795 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
796 void PNGFAPI |
|
797 png_set_gamma_fixed(png_structp png_ptr, png_fixed_point scrn_gamma, |
|
798 png_fixed_point file_gamma) |
|
799 { |
|
800 png_debug(1, "in png_set_gamma_fixed"); |
|
801 |
|
802 if (png_ptr == NULL) |
|
803 return; |
|
804 |
|
805 /* New in libpng-1.5.4 - reserve particular negative values as flags. */ |
|
806 scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/); |
|
807 file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/); |
|
808 |
|
809 #if PNG_LIBPNG_VER >= 10600 |
|
810 /* Checking the gamma values for being >0 was added in 1.5.4 along with the |
|
811 * premultiplied alpha support; this actually hides an undocumented feature |
|
812 * of the previous implementation which allowed gamma processing to be |
|
813 * disabled in background handling. There is no evidence (so far) that this |
|
814 * was being used; however, png_set_background itself accepted and must still |
|
815 * accept '0' for the gamma value it takes, because it isn't always used. |
|
816 * |
|
817 * Since this is an API change (albeit a very minor one that removes an |
|
818 * undocumented API feature) it will not be made until libpng-1.6.0. |
|
819 */ |
|
820 if (file_gamma <= 0) |
|
821 png_error(png_ptr, "invalid file gamma in png_set_gamma"); |
|
822 |
|
823 if (scrn_gamma <= 0) |
|
824 png_error(png_ptr, "invalid screen gamma in png_set_gamma"); |
|
825 #endif |
|
826 |
|
827 /* Set the gamma values unconditionally - this overrides the value in the PNG |
|
828 * file if a gAMA chunk was present. png_set_alpha_mode provides a |
|
829 * different, easier, way to default the file gamma. |
|
830 */ |
|
831 png_ptr->gamma = file_gamma; |
|
832 png_ptr->screen_gamma = scrn_gamma; |
|
833 } |
|
834 |
|
835 # ifdef PNG_FLOATING_POINT_SUPPORTED |
|
836 void PNGAPI |
|
837 png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma) |
|
838 { |
|
839 png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma), |
|
840 convert_gamma_value(png_ptr, file_gamma)); |
|
841 } |
|
842 # endif /* FLOATING_POINT_SUPPORTED */ |
|
843 #endif /* READ_GAMMA */ |
|
844 |
|
845 #ifdef PNG_READ_EXPAND_SUPPORTED |
|
846 /* Expand paletted images to RGB, expand grayscale images of |
|
847 * less than 8-bit depth to 8-bit depth, and expand tRNS chunks |
|
848 * to alpha channels. |
|
849 */ |
|
850 void PNGAPI |
|
851 png_set_expand(png_structp png_ptr) |
|
852 { |
|
853 png_debug(1, "in png_set_expand"); |
|
854 |
|
855 if (png_ptr == NULL) |
|
856 return; |
|
857 |
|
858 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
|
859 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
860 } |
|
861 |
|
862 /* GRR 19990627: the following three functions currently are identical |
|
863 * to png_set_expand(). However, it is entirely reasonable that someone |
|
864 * might wish to expand an indexed image to RGB but *not* expand a single, |
|
865 * fully transparent palette entry to a full alpha channel--perhaps instead |
|
866 * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace |
|
867 * the transparent color with a particular RGB value, or drop tRNS entirely. |
|
868 * IOW, a future version of the library may make the transformations flag |
|
869 * a bit more fine-grained, with separate bits for each of these three |
|
870 * functions. |
|
871 * |
|
872 * More to the point, these functions make it obvious what libpng will be |
|
873 * doing, whereas "expand" can (and does) mean any number of things. |
|
874 * |
|
875 * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified |
|
876 * to expand only the sample depth but not to expand the tRNS to alpha |
|
877 * and its name was changed to png_set_expand_gray_1_2_4_to_8(). |
|
878 */ |
|
879 |
|
880 /* Expand paletted images to RGB. */ |
|
881 void PNGAPI |
|
882 png_set_palette_to_rgb(png_structp png_ptr) |
|
883 { |
|
884 png_debug(1, "in png_set_palette_to_rgb"); |
|
885 |
|
886 if (png_ptr == NULL) |
|
887 return; |
|
888 |
|
889 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
|
890 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
891 } |
|
892 |
|
893 /* Expand grayscale images of less than 8-bit depth to 8 bits. */ |
|
894 void PNGAPI |
|
895 png_set_expand_gray_1_2_4_to_8(png_structp png_ptr) |
|
896 { |
|
897 png_debug(1, "in png_set_expand_gray_1_2_4_to_8"); |
|
898 |
|
899 if (png_ptr == NULL) |
|
900 return; |
|
901 |
|
902 png_ptr->transformations |= PNG_EXPAND; |
|
903 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
904 } |
|
905 |
|
906 |
|
907 |
|
908 /* Expand tRNS chunks to alpha channels. */ |
|
909 void PNGAPI |
|
910 png_set_tRNS_to_alpha(png_structp png_ptr) |
|
911 { |
|
912 png_debug(1, "in png_set_tRNS_to_alpha"); |
|
913 |
|
914 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
|
915 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
916 } |
|
917 #endif /* defined(PNG_READ_EXPAND_SUPPORTED) */ |
|
918 |
|
919 #ifdef PNG_READ_EXPAND_16_SUPPORTED |
|
920 /* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise |
|
921 * it may not work correctly.) |
|
922 */ |
|
923 void PNGAPI |
|
924 png_set_expand_16(png_structp png_ptr) |
|
925 { |
|
926 png_debug(1, "in png_set_expand_16"); |
|
927 |
|
928 if (png_ptr == NULL) |
|
929 return; |
|
930 |
|
931 png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS); |
|
932 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
933 |
|
934 /* New API, make sure apps call the correct initializers: */ |
|
935 png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED; |
|
936 } |
|
937 #endif |
|
938 |
|
939 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
|
940 void PNGAPI |
|
941 png_set_gray_to_rgb(png_structp png_ptr) |
|
942 { |
|
943 png_debug(1, "in png_set_gray_to_rgb"); |
|
944 |
|
945 if (png_ptr != NULL) |
|
946 { |
|
947 /* Because rgb must be 8 bits or more: */ |
|
948 png_set_expand_gray_1_2_4_to_8(png_ptr); |
|
949 png_ptr->transformations |= PNG_GRAY_TO_RGB; |
|
950 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
951 } |
|
952 } |
|
953 #endif |
|
954 |
|
955 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
|
956 void PNGFAPI |
|
957 png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, |
|
958 png_fixed_point red, png_fixed_point green) |
|
959 { |
|
960 png_debug(1, "in png_set_rgb_to_gray"); |
|
961 |
|
962 if (png_ptr == NULL) |
|
963 return; |
|
964 |
|
965 switch(error_action) |
|
966 { |
|
967 case 1: |
|
968 png_ptr->transformations |= PNG_RGB_TO_GRAY; |
|
969 break; |
|
970 |
|
971 case 2: |
|
972 png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; |
|
973 break; |
|
974 |
|
975 case 3: |
|
976 png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; |
|
977 break; |
|
978 |
|
979 default: |
|
980 png_error(png_ptr, "invalid error action to rgb_to_gray"); |
|
981 break; |
|
982 } |
|
983 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
984 #ifdef PNG_READ_EXPAND_SUPPORTED |
|
985 png_ptr->transformations |= PNG_EXPAND; |
|
986 #else |
|
987 { |
|
988 png_warning(png_ptr, |
|
989 "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED"); |
|
990 |
|
991 png_ptr->transformations &= ~PNG_RGB_TO_GRAY; |
|
992 } |
|
993 #endif |
|
994 { |
|
995 if (red >= 0 && green >= 0 && red + green <= PNG_FP_1) |
|
996 { |
|
997 png_uint_16 red_int, green_int; |
|
998 |
|
999 red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L); |
|
1000 green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L); |
|
1001 |
|
1002 png_ptr->rgb_to_gray_red_coeff = red_int; |
|
1003 png_ptr->rgb_to_gray_green_coeff = green_int; |
|
1004 png_ptr->rgb_to_gray_blue_coeff = |
|
1005 (png_uint_16)(32768 - red_int - green_int); |
|
1006 } |
|
1007 |
|
1008 else |
|
1009 { |
|
1010 if (red >= 0 && green >= 0) |
|
1011 png_warning(png_ptr, |
|
1012 "ignoring out of range rgb_to_gray coefficients"); |
|
1013 |
|
1014 /* Use the defaults, from the cHRM chunk if set, else the built in Rec |
|
1015 * 709 values (which correspond to sRGB, so we don't have to worry |
|
1016 * about the sRGB chunk!) |
|
1017 */ |
|
1018 if (png_ptr->rgb_to_gray_red_coeff == 0 && |
|
1019 png_ptr->rgb_to_gray_green_coeff == 0 && |
|
1020 png_ptr->rgb_to_gray_blue_coeff == 0) |
|
1021 { |
|
1022 png_ptr->rgb_to_gray_red_coeff = 6968; /* .212671 * 32768 + .5 */ |
|
1023 png_ptr->rgb_to_gray_green_coeff = 23434; /* .715160 * 32768 + .5 */ |
|
1024 png_ptr->rgb_to_gray_blue_coeff = 2366; |
|
1025 } |
|
1026 } |
|
1027 } |
|
1028 } |
|
1029 |
|
1030 #ifdef PNG_FLOATING_POINT_SUPPORTED |
|
1031 /* Convert a RGB image to a grayscale of the same width. This allows us, |
|
1032 * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. |
|
1033 */ |
|
1034 |
|
1035 void PNGAPI |
|
1036 png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red, |
|
1037 double green) |
|
1038 { |
|
1039 if (png_ptr == NULL) |
|
1040 return; |
|
1041 |
|
1042 png_set_rgb_to_gray_fixed(png_ptr, error_action, |
|
1043 png_fixed(png_ptr, red, "rgb to gray red coefficient"), |
|
1044 png_fixed(png_ptr, green, "rgb to gray green coefficient")); |
|
1045 } |
|
1046 #endif /* FLOATING POINT */ |
|
1047 |
|
1048 #endif |
|
1049 |
|
1050 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ |
|
1051 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) |
|
1052 void PNGAPI |
|
1053 png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr |
|
1054 read_user_transform_fn) |
|
1055 { |
|
1056 png_debug(1, "in png_set_read_user_transform_fn"); |
|
1057 |
|
1058 if (png_ptr == NULL) |
|
1059 return; |
|
1060 |
|
1061 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED |
|
1062 png_ptr->transformations |= PNG_USER_TRANSFORM; |
|
1063 png_ptr->read_user_transform_fn = read_user_transform_fn; |
|
1064 #endif |
|
1065 } |
|
1066 #endif |
|
1067 |
|
1068 #ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
1069 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
1070 /* In the case of gamma transformations only do transformations on images where |
|
1071 * the [file] gamma and screen_gamma are not close reciprocals, otherwise it |
|
1072 * slows things down slightly, and also needlessly introduces small errors. |
|
1073 */ |
|
1074 static int /* PRIVATE */ |
|
1075 png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma) |
|
1076 { |
|
1077 /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma |
|
1078 * correction as a difference of the overall transform from 1.0 |
|
1079 * |
|
1080 * We want to compare the threshold with s*f - 1, if we get |
|
1081 * overflow here it is because of wacky gamma values so we |
|
1082 * turn on processing anyway. |
|
1083 */ |
|
1084 png_fixed_point gtest; |
|
1085 return !png_muldiv(>est, screen_gamma, file_gamma, PNG_FP_1) || |
|
1086 png_gamma_significant(gtest); |
|
1087 } |
|
1088 #endif |
|
1089 |
|
1090 /* Initialize everything needed for the read. This includes modifying |
|
1091 * the palette. |
|
1092 */ |
|
1093 |
|
1094 /*For the moment 'png_init_palette_transformations' and |
|
1095 * 'png_init_rgb_transformations' only do some flag canceling optimizations. |
|
1096 * The intent is that these two routines should have palette or rgb operations |
|
1097 * extracted from 'png_init_read_transformations'. |
|
1098 */ |
|
1099 static void /* PRIVATE */ |
|
1100 png_init_palette_transformations(png_structp png_ptr) |
|
1101 { |
|
1102 /* Called to handle the (input) palette case. In png_do_read_transformations |
|
1103 * the first step is to expand the palette if requested, so this code must |
|
1104 * take care to only make changes that are invariant with respect to the |
|
1105 * palette expansion, or only do them if there is no expansion. |
|
1106 * |
|
1107 * STRIP_ALPHA has already been handled in the caller (by setting num_trans |
|
1108 * to 0.) |
|
1109 */ |
|
1110 int input_has_alpha = 0; |
|
1111 int input_has_transparency = 0; |
|
1112 |
|
1113 if (png_ptr->num_trans > 0) |
|
1114 { |
|
1115 int i; |
|
1116 |
|
1117 /* Ignore if all the entries are opaque (unlikely!) */ |
|
1118 for (i=0; i<png_ptr->num_trans; ++i) |
|
1119 if (png_ptr->trans_alpha[i] == 255) |
|
1120 continue; |
|
1121 else if (png_ptr->trans_alpha[i] == 0) |
|
1122 input_has_transparency = 1; |
|
1123 else |
|
1124 input_has_alpha = 1; |
|
1125 } |
|
1126 |
|
1127 /* If no alpha we can optimize. */ |
|
1128 if (!input_has_alpha) |
|
1129 { |
|
1130 /* Any alpha means background and associative alpha processing is |
|
1131 * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA |
|
1132 * and ENCODE_ALPHA are irrelevant. |
|
1133 */ |
|
1134 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
|
1135 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
|
1136 |
|
1137 if (!input_has_transparency) |
|
1138 png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); |
|
1139 } |
|
1140 |
|
1141 #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1142 /* png_set_background handling - deals with the complexity of whether the |
|
1143 * background color is in the file format or the screen format in the case |
|
1144 * where an 'expand' will happen. |
|
1145 */ |
|
1146 |
|
1147 /* The following code cannot be entered in the alpha pre-multiplication case |
|
1148 * because PNG_BACKGROUND_EXPAND is cancelled below. |
|
1149 */ |
|
1150 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && |
|
1151 (png_ptr->transformations & PNG_EXPAND)) |
|
1152 { |
|
1153 { |
|
1154 png_ptr->background.red = |
|
1155 png_ptr->palette[png_ptr->background.index].red; |
|
1156 png_ptr->background.green = |
|
1157 png_ptr->palette[png_ptr->background.index].green; |
|
1158 png_ptr->background.blue = |
|
1159 png_ptr->palette[png_ptr->background.index].blue; |
|
1160 |
|
1161 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED |
|
1162 if (png_ptr->transformations & PNG_INVERT_ALPHA) |
|
1163 { |
|
1164 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
1165 { |
|
1166 /* Invert the alpha channel (in tRNS) unless the pixels are |
|
1167 * going to be expanded, in which case leave it for later |
|
1168 */ |
|
1169 int i, istop = png_ptr->num_trans; |
|
1170 |
|
1171 for (i=0; i<istop; i++) |
|
1172 png_ptr->trans_alpha[i] = (png_byte)(255 - |
|
1173 png_ptr->trans_alpha[i]); |
|
1174 } |
|
1175 } |
|
1176 #endif /* PNG_READ_INVERT_ALPHA_SUPPORTED */ |
|
1177 } |
|
1178 } /* background expand and (therefore) no alpha association. */ |
|
1179 #endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */ |
|
1180 } |
|
1181 |
|
1182 static void /* PRIVATE */ |
|
1183 png_init_rgb_transformations(png_structp png_ptr) |
|
1184 { |
|
1185 /* Added to libpng-1.5.4: check the color type to determine whether there |
|
1186 * is any alpha or transparency in the image and simply cancel the |
|
1187 * background and alpha mode stuff if there isn't. |
|
1188 */ |
|
1189 int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0; |
|
1190 int input_has_transparency = png_ptr->num_trans > 0; |
|
1191 |
|
1192 /* If no alpha we can optimize. */ |
|
1193 if (!input_has_alpha) |
|
1194 { |
|
1195 /* Any alpha means background and associative alpha processing is |
|
1196 * required, however if the alpha is 0 or 1 throughout OPTIIMIZE_ALPHA |
|
1197 * and ENCODE_ALPHA are irrelevant. |
|
1198 */ |
|
1199 # ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
1200 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
|
1201 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
|
1202 # endif |
|
1203 |
|
1204 if (!input_has_transparency) |
|
1205 png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); |
|
1206 } |
|
1207 |
|
1208 #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1209 /* png_set_background handling - deals with the complexity of whether the |
|
1210 * background color is in the file format or the screen format in the case |
|
1211 * where an 'expand' will happen. |
|
1212 */ |
|
1213 |
|
1214 /* The following code cannot be entered in the alpha pre-multiplication case |
|
1215 * because PNG_BACKGROUND_EXPAND is cancelled below. |
|
1216 */ |
|
1217 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && |
|
1218 (png_ptr->transformations & PNG_EXPAND) && |
|
1219 !(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) |
|
1220 /* i.e., GRAY or GRAY_ALPHA */ |
|
1221 { |
|
1222 { |
|
1223 /* Expand background and tRNS chunks */ |
|
1224 switch (png_ptr->bit_depth) |
|
1225 { |
|
1226 case 1: |
|
1227 png_ptr->background.gray *= (png_uint_16)0xff; |
|
1228 png_ptr->background.red = png_ptr->background.green |
|
1229 = png_ptr->background.blue = png_ptr->background.gray; |
|
1230 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
1231 { |
|
1232 png_ptr->trans_color.gray *= (png_uint_16)0xff; |
|
1233 png_ptr->trans_color.red = png_ptr->trans_color.green |
|
1234 = png_ptr->trans_color.blue = png_ptr->trans_color.gray; |
|
1235 } |
|
1236 break; |
|
1237 |
|
1238 case 2: |
|
1239 png_ptr->background.gray *= (png_uint_16)0x55; |
|
1240 png_ptr->background.red = png_ptr->background.green |
|
1241 = png_ptr->background.blue = png_ptr->background.gray; |
|
1242 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
1243 { |
|
1244 png_ptr->trans_color.gray *= (png_uint_16)0x55; |
|
1245 png_ptr->trans_color.red = png_ptr->trans_color.green |
|
1246 = png_ptr->trans_color.blue = png_ptr->trans_color.gray; |
|
1247 } |
|
1248 break; |
|
1249 |
|
1250 case 4: |
|
1251 png_ptr->background.gray *= (png_uint_16)0x11; |
|
1252 png_ptr->background.red = png_ptr->background.green |
|
1253 = png_ptr->background.blue = png_ptr->background.gray; |
|
1254 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
1255 { |
|
1256 png_ptr->trans_color.gray *= (png_uint_16)0x11; |
|
1257 png_ptr->trans_color.red = png_ptr->trans_color.green |
|
1258 = png_ptr->trans_color.blue = png_ptr->trans_color.gray; |
|
1259 } |
|
1260 break; |
|
1261 |
|
1262 default: |
|
1263 |
|
1264 case 8: |
|
1265 |
|
1266 case 16: |
|
1267 png_ptr->background.red = png_ptr->background.green |
|
1268 = png_ptr->background.blue = png_ptr->background.gray; |
|
1269 break; |
|
1270 } |
|
1271 } |
|
1272 } /* background expand and (therefore) no alpha association. */ |
|
1273 #endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */ |
|
1274 } |
|
1275 |
|
1276 void /* PRIVATE */ |
|
1277 png_init_read_transformations(png_structp png_ptr) |
|
1278 { |
|
1279 png_debug(1, "in png_init_read_transformations"); |
|
1280 |
|
1281 /* This internal function is called from png_read_start_row in pngrutil.c |
|
1282 * and it is called before the 'rowbytes' calculation is done, so the code |
|
1283 * in here can change or update the transformations flags. |
|
1284 * |
|
1285 * First do updates that do not depend on the details of the PNG image data |
|
1286 * being processed. |
|
1287 */ |
|
1288 |
|
1289 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
1290 /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds |
|
1291 * png_set_alpha_mode and this is another source for a default file gamma so |
|
1292 * the test needs to be performed later - here. In addition prior to 1.5.4 |
|
1293 * the tests were repeated for the PALETTE color type here - this is no |
|
1294 * longer necessary (and doesn't seem to have been necessary before.) |
|
1295 */ |
|
1296 { |
|
1297 /* The following temporary indicates if overall gamma correction is |
|
1298 * required. |
|
1299 */ |
|
1300 int gamma_correction = 0; |
|
1301 |
|
1302 if (png_ptr->gamma != 0) /* has been set */ |
|
1303 { |
|
1304 if (png_ptr->screen_gamma != 0) /* screen set too */ |
|
1305 gamma_correction = png_gamma_threshold(png_ptr->gamma, |
|
1306 png_ptr->screen_gamma); |
|
1307 |
|
1308 else |
|
1309 /* Assume the output matches the input; a long time default behavior |
|
1310 * of libpng, although the standard has nothing to say about this. |
|
1311 */ |
|
1312 png_ptr->screen_gamma = png_reciprocal(png_ptr->gamma); |
|
1313 } |
|
1314 |
|
1315 else if (png_ptr->screen_gamma != 0) |
|
1316 /* The converse - assume the file matches the screen, note that this |
|
1317 * perhaps undesireable default can (from 1.5.4) be changed by calling |
|
1318 * png_set_alpha_mode (even if the alpha handling mode isn't required |
|
1319 * or isn't changed from the default.) |
|
1320 */ |
|
1321 png_ptr->gamma = png_reciprocal(png_ptr->screen_gamma); |
|
1322 |
|
1323 else /* neither are set */ |
|
1324 /* Just in case the following prevents any processing - file and screen |
|
1325 * are both assumed to be linear and there is no way to introduce a |
|
1326 * third gamma value other than png_set_background with 'UNIQUE', and, |
|
1327 * prior to 1.5.4 |
|
1328 */ |
|
1329 png_ptr->screen_gamma = png_ptr->gamma = PNG_FP_1; |
|
1330 |
|
1331 /* Now turn the gamma transformation on or off as appropriate. Notice |
|
1332 * that PNG_GAMMA just refers to the file->screen correction. Alpha |
|
1333 * composition may independently cause gamma correction because it needs |
|
1334 * linear data (e.g. if the file has a gAMA chunk but the screen gamma |
|
1335 * hasn't been specified.) In any case this flag may get turned off in |
|
1336 * the code immediately below if the transform can be handled outside the |
|
1337 * row loop. |
|
1338 */ |
|
1339 if (gamma_correction) |
|
1340 png_ptr->transformations |= PNG_GAMMA; |
|
1341 |
|
1342 else |
|
1343 png_ptr->transformations &= ~PNG_GAMMA; |
|
1344 } |
|
1345 #endif |
|
1346 |
|
1347 /* Certain transformations have the effect of preventing other |
|
1348 * transformations that happen afterward in png_do_read_transformations, |
|
1349 * resolve the interdependencies here. From the code of |
|
1350 * png_do_read_transformations the order is: |
|
1351 * |
|
1352 * 1) PNG_EXPAND (including PNG_EXPAND_tRNS) |
|
1353 * 2) PNG_STRIP_ALPHA (if no compose) |
|
1354 * 3) PNG_RGB_TO_GRAY |
|
1355 * 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY |
|
1356 * 5) PNG_COMPOSE |
|
1357 * 6) PNG_GAMMA |
|
1358 * 7) PNG_STRIP_ALPHA (if compose) |
|
1359 * 8) PNG_ENCODE_ALPHA |
|
1360 * 9) PNG_SCALE_16_TO_8 |
|
1361 * 10) PNG_16_TO_8 |
|
1362 * 11) PNG_QUANTIZE (converts to palette) |
|
1363 * 12) PNG_EXPAND_16 |
|
1364 * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY |
|
1365 * 14) PNG_INVERT_MONO |
|
1366 * 15) PNG_SHIFT |
|
1367 * 16) PNG_PACK |
|
1368 * 17) PNG_BGR |
|
1369 * 18) PNG_PACKSWAP |
|
1370 * 19) PNG_FILLER (includes PNG_ADD_ALPHA) |
|
1371 * 20) PNG_INVERT_ALPHA |
|
1372 * 21) PNG_SWAP_ALPHA |
|
1373 * 22) PNG_SWAP_BYTES |
|
1374 * 23) PNG_USER_TRANSFORM [must be last] |
|
1375 */ |
|
1376 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
|
1377 if ((png_ptr->transformations & PNG_STRIP_ALPHA) && |
|
1378 !(png_ptr->transformations & PNG_COMPOSE)) |
|
1379 { |
|
1380 /* Stripping the alpha channel happens immediately after the 'expand' |
|
1381 * transformations, before all other transformation, so it cancels out |
|
1382 * the alpha handling. It has the side effect negating the effect of |
|
1383 * PNG_EXPAND_tRNS too: |
|
1384 */ |
|
1385 png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA | |
|
1386 PNG_EXPAND_tRNS); |
|
1387 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
|
1388 |
|
1389 /* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen |
|
1390 * so transparency information would remain just so long as it wasn't |
|
1391 * expanded. This produces unexpected API changes if the set of things |
|
1392 * that do PNG_EXPAND_tRNS changes (perfectly possible given the |
|
1393 * documentation - which says ask for what you want, accept what you |
|
1394 * get.) This makes the behavior consistent from 1.5.4: |
|
1395 */ |
|
1396 png_ptr->num_trans = 0; |
|
1397 } |
|
1398 #endif /* STRIP_ALPHA supported, no COMPOSE */ |
|
1399 |
|
1400 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
1401 /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA |
|
1402 * settings will have no effect. |
|
1403 */ |
|
1404 if (!png_gamma_significant(png_ptr->screen_gamma)) |
|
1405 { |
|
1406 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
|
1407 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
|
1408 } |
|
1409 #endif |
|
1410 |
|
1411 #if defined(PNG_READ_EXPAND_SUPPORTED) && \ |
|
1412 defined(PNG_READ_BACKGROUND_SUPPORTED) && \ |
|
1413 defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
1414 /* Detect gray background and attempt to enable optimization for |
|
1415 * gray --> RGB case. |
|
1416 * |
|
1417 * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or |
|
1418 * RGB_ALPHA (in which case need_expand is superfluous anyway), the |
|
1419 * background color might actually be gray yet not be flagged as such. |
|
1420 * This is not a problem for the current code, which uses |
|
1421 * PNG_BACKGROUND_IS_GRAY only to decide when to do the |
|
1422 * png_do_gray_to_rgb() transformation. |
|
1423 * |
|
1424 * TODO: this code needs to be revised to avoid the complexity and |
|
1425 * interdependencies. The color type of the background should be recorded in |
|
1426 * png_set_background, along with the bit depth, then the code has a record |
|
1427 * of exactly what color space the background is currently in. |
|
1428 */ |
|
1429 if (png_ptr->transformations & PNG_BACKGROUND_EXPAND) |
|
1430 { |
|
1431 /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if |
|
1432 * the file was greyscale the background value is gray. |
|
1433 */ |
|
1434 if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) |
|
1435 png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; |
|
1436 } |
|
1437 |
|
1438 else if (png_ptr->transformations & PNG_COMPOSE) |
|
1439 { |
|
1440 /* PNG_COMPOSE: png_set_background was called with need_expand false, |
|
1441 * so the color is in the color space of the output or png_set_alpha_mode |
|
1442 * was called and the color is black. Ignore RGB_TO_GRAY because that |
|
1443 * happens before GRAY_TO_RGB. |
|
1444 */ |
|
1445 if (png_ptr->transformations & PNG_GRAY_TO_RGB) |
|
1446 { |
|
1447 if (png_ptr->background.red == png_ptr->background.green && |
|
1448 png_ptr->background.red == png_ptr->background.blue) |
|
1449 { |
|
1450 png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; |
|
1451 png_ptr->background.gray = png_ptr->background.red; |
|
1452 } |
|
1453 } |
|
1454 } |
|
1455 #endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED (etc) */ |
|
1456 |
|
1457 /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations |
|
1458 * can be performed directly on the palette, and some (such as rgb to gray) |
|
1459 * can be optimized inside the palette. This is particularly true of the |
|
1460 * composite (background and alpha) stuff, which can be pretty much all done |
|
1461 * in the palette even if the result is expanded to RGB or gray afterward. |
|
1462 * |
|
1463 * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and |
|
1464 * earlier and the palette stuff is actually handled on the first row. This |
|
1465 * leads to the reported bug that the palette returned by png_get_PLTE is not |
|
1466 * updated. |
|
1467 */ |
|
1468 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
1469 png_init_palette_transformations(png_ptr); |
|
1470 |
|
1471 else |
|
1472 png_init_rgb_transformations(png_ptr); |
|
1473 |
|
1474 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ |
|
1475 defined(PNG_READ_EXPAND_16_SUPPORTED) |
|
1476 if ((png_ptr->transformations & PNG_EXPAND_16) && |
|
1477 (png_ptr->transformations & PNG_COMPOSE) && |
|
1478 !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && |
|
1479 png_ptr->bit_depth != 16) |
|
1480 { |
|
1481 /* TODO: fix this. Because the expand_16 operation is after the compose |
|
1482 * handling the background color must be 8, not 16, bits deep, but the |
|
1483 * application will supply a 16-bit value so reduce it here. |
|
1484 * |
|
1485 * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at |
|
1486 * present, so that case is ok (until do_expand_16 is moved.) |
|
1487 * |
|
1488 * NOTE: this discards the low 16 bits of the user supplied background |
|
1489 * color, but until expand_16 works properly there is no choice! |
|
1490 */ |
|
1491 # define CHOP(x) (x)=((png_uint_16)(((png_uint_32)(x)*255+32895) >> 16)) |
|
1492 CHOP(png_ptr->background.red); |
|
1493 CHOP(png_ptr->background.green); |
|
1494 CHOP(png_ptr->background.blue); |
|
1495 CHOP(png_ptr->background.gray); |
|
1496 # undef CHOP |
|
1497 } |
|
1498 #endif /* PNG_READ_BACKGROUND_SUPPORTED && PNG_READ_EXPAND_16_SUPPORTED */ |
|
1499 |
|
1500 /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the |
|
1501 * background support (see the comments in scripts/pnglibconf.dfa), this |
|
1502 * allows pre-multiplication of the alpha channel to be implemented as |
|
1503 * compositing on black. This is probably sub-optimal and has been done in |
|
1504 * 1.5.4 betas simply to enable external critique and testing (i.e. to |
|
1505 * implement the new API quickly, without lots of internal changes.) |
|
1506 */ |
|
1507 |
|
1508 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
1509 # ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
1510 /* Includes ALPHA_MODE */ |
|
1511 png_ptr->background_1 = png_ptr->background; |
|
1512 # endif |
|
1513 |
|
1514 /* This needs to change - in the palette image case a whole set of tables are |
|
1515 * built when it would be quicker to just calculate the correct value for |
|
1516 * each palette entry directly. Also, the test is too tricky - why check |
|
1517 * PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that |
|
1518 * PNG_GAMMA is cancelled even if the gamma is known? The test excludes the |
|
1519 * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction |
|
1520 * the gamma tables will not be built even if composition is required on a |
|
1521 * gamma encoded value. |
|
1522 * |
|
1523 * In 1.5.4 this is addressed below by an additional check on the individual |
|
1524 * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the |
|
1525 * tables. |
|
1526 */ |
|
1527 if ((png_ptr->transformations & PNG_GAMMA) |
|
1528 || ((png_ptr->transformations & PNG_RGB_TO_GRAY) |
|
1529 && (png_gamma_significant(png_ptr->gamma) || |
|
1530 png_gamma_significant(png_ptr->screen_gamma))) |
|
1531 || ((png_ptr->transformations & PNG_COMPOSE) |
|
1532 && (png_gamma_significant(png_ptr->gamma) |
|
1533 || png_gamma_significant(png_ptr->screen_gamma) |
|
1534 # ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
1535 || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE |
|
1536 && png_gamma_significant(png_ptr->background_gamma)) |
|
1537 # endif |
|
1538 )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) |
|
1539 && png_gamma_significant(png_ptr->screen_gamma)) |
|
1540 ) |
|
1541 { |
|
1542 png_build_gamma_table(png_ptr, png_ptr->bit_depth); |
|
1543 |
|
1544 #ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
1545 if (png_ptr->transformations & PNG_COMPOSE) |
|
1546 { |
|
1547 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
1548 { |
|
1549 /* We don't get to here unless there is a tRNS chunk with non-opaque |
|
1550 * entries - see the checking code at the start of this function. |
|
1551 */ |
|
1552 png_color back, back_1; |
|
1553 png_colorp palette = png_ptr->palette; |
|
1554 int num_palette = png_ptr->num_palette; |
|
1555 int i; |
|
1556 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) |
|
1557 { |
|
1558 |
|
1559 back.red = png_ptr->gamma_table[png_ptr->background.red]; |
|
1560 back.green = png_ptr->gamma_table[png_ptr->background.green]; |
|
1561 back.blue = png_ptr->gamma_table[png_ptr->background.blue]; |
|
1562 |
|
1563 back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; |
|
1564 back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; |
|
1565 back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; |
|
1566 } |
|
1567 else |
|
1568 { |
|
1569 png_fixed_point g, gs; |
|
1570 |
|
1571 switch (png_ptr->background_gamma_type) |
|
1572 { |
|
1573 case PNG_BACKGROUND_GAMMA_SCREEN: |
|
1574 g = (png_ptr->screen_gamma); |
|
1575 gs = PNG_FP_1; |
|
1576 break; |
|
1577 |
|
1578 case PNG_BACKGROUND_GAMMA_FILE: |
|
1579 g = png_reciprocal(png_ptr->gamma); |
|
1580 gs = png_reciprocal2(png_ptr->gamma, |
|
1581 png_ptr->screen_gamma); |
|
1582 break; |
|
1583 |
|
1584 case PNG_BACKGROUND_GAMMA_UNIQUE: |
|
1585 g = png_reciprocal(png_ptr->background_gamma); |
|
1586 gs = png_reciprocal2(png_ptr->background_gamma, |
|
1587 png_ptr->screen_gamma); |
|
1588 break; |
|
1589 default: |
|
1590 g = PNG_FP_1; /* back_1 */ |
|
1591 gs = PNG_FP_1; /* back */ |
|
1592 break; |
|
1593 } |
|
1594 |
|
1595 if (png_gamma_significant(gs)) |
|
1596 { |
|
1597 back.red = png_gamma_8bit_correct(png_ptr->background.red, |
|
1598 gs); |
|
1599 back.green = png_gamma_8bit_correct(png_ptr->background.green, |
|
1600 gs); |
|
1601 back.blue = png_gamma_8bit_correct(png_ptr->background.blue, |
|
1602 gs); |
|
1603 } |
|
1604 |
|
1605 else |
|
1606 { |
|
1607 back.red = (png_byte)png_ptr->background.red; |
|
1608 back.green = (png_byte)png_ptr->background.green; |
|
1609 back.blue = (png_byte)png_ptr->background.blue; |
|
1610 } |
|
1611 |
|
1612 if (png_gamma_significant(g)) |
|
1613 { |
|
1614 back_1.red = png_gamma_8bit_correct(png_ptr->background.red, |
|
1615 g); |
|
1616 back_1.green = png_gamma_8bit_correct( |
|
1617 png_ptr->background.green, g); |
|
1618 back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue, |
|
1619 g); |
|
1620 } |
|
1621 |
|
1622 else |
|
1623 { |
|
1624 back_1.red = (png_byte)png_ptr->background.red; |
|
1625 back_1.green = (png_byte)png_ptr->background.green; |
|
1626 back_1.blue = (png_byte)png_ptr->background.blue; |
|
1627 } |
|
1628 } |
|
1629 |
|
1630 for (i = 0; i < num_palette; i++) |
|
1631 { |
|
1632 if (i < (int)png_ptr->num_trans && |
|
1633 png_ptr->trans_alpha[i] != 0xff) |
|
1634 { |
|
1635 if (png_ptr->trans_alpha[i] == 0) |
|
1636 { |
|
1637 palette[i] = back; |
|
1638 } |
|
1639 else /* if (png_ptr->trans_alpha[i] != 0xff) */ |
|
1640 { |
|
1641 png_byte v, w; |
|
1642 |
|
1643 v = png_ptr->gamma_to_1[palette[i].red]; |
|
1644 png_composite(w, v, png_ptr->trans_alpha[i], back_1.red); |
|
1645 palette[i].red = png_ptr->gamma_from_1[w]; |
|
1646 |
|
1647 v = png_ptr->gamma_to_1[palette[i].green]; |
|
1648 png_composite(w, v, png_ptr->trans_alpha[i], back_1.green); |
|
1649 palette[i].green = png_ptr->gamma_from_1[w]; |
|
1650 |
|
1651 v = png_ptr->gamma_to_1[palette[i].blue]; |
|
1652 png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue); |
|
1653 palette[i].blue = png_ptr->gamma_from_1[w]; |
|
1654 } |
|
1655 } |
|
1656 else |
|
1657 { |
|
1658 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
|
1659 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
|
1660 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
|
1661 } |
|
1662 } |
|
1663 |
|
1664 /* Prevent the transformations being done again. |
|
1665 * |
|
1666 * NOTE: this is highly dubious; it zaps the transformations in |
|
1667 * place. This seems inconsistent with the general treatment of the |
|
1668 * transformations elsewhere. |
|
1669 */ |
|
1670 png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA); |
|
1671 } /* color_type == PNG_COLOR_TYPE_PALETTE */ |
|
1672 |
|
1673 /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ |
|
1674 else /* color_type != PNG_COLOR_TYPE_PALETTE */ |
|
1675 { |
|
1676 png_fixed_point g = PNG_FP_1; |
|
1677 png_fixed_point gs = PNG_FP_1; |
|
1678 |
|
1679 switch (png_ptr->background_gamma_type) |
|
1680 { |
|
1681 case PNG_BACKGROUND_GAMMA_SCREEN: |
|
1682 g = png_ptr->screen_gamma; |
|
1683 /* gs = PNG_FP_1; */ |
|
1684 break; |
|
1685 |
|
1686 case PNG_BACKGROUND_GAMMA_FILE: |
|
1687 g = png_reciprocal(png_ptr->gamma); |
|
1688 gs = png_reciprocal2(png_ptr->gamma, png_ptr->screen_gamma); |
|
1689 break; |
|
1690 |
|
1691 case PNG_BACKGROUND_GAMMA_UNIQUE: |
|
1692 g = png_reciprocal(png_ptr->background_gamma); |
|
1693 gs = png_reciprocal2(png_ptr->background_gamma, |
|
1694 png_ptr->screen_gamma); |
|
1695 break; |
|
1696 |
|
1697 default: |
|
1698 png_error(png_ptr, "invalid background gamma type"); |
|
1699 } |
|
1700 |
|
1701 png_ptr->background_1.gray = png_gamma_correct(png_ptr, |
|
1702 png_ptr->background.gray, g); |
|
1703 |
|
1704 png_ptr->background.gray = png_gamma_correct(png_ptr, |
|
1705 png_ptr->background.gray, gs); |
|
1706 |
|
1707 if ((png_ptr->background.red != png_ptr->background.green) || |
|
1708 (png_ptr->background.red != png_ptr->background.blue) || |
|
1709 (png_ptr->background.red != png_ptr->background.gray)) |
|
1710 { |
|
1711 /* RGB or RGBA with color background */ |
|
1712 png_ptr->background_1.red = png_gamma_correct(png_ptr, |
|
1713 png_ptr->background.red, g); |
|
1714 |
|
1715 png_ptr->background_1.green = png_gamma_correct(png_ptr, |
|
1716 png_ptr->background.green, g); |
|
1717 |
|
1718 png_ptr->background_1.blue = png_gamma_correct(png_ptr, |
|
1719 png_ptr->background.blue, g); |
|
1720 |
|
1721 png_ptr->background.red = png_gamma_correct(png_ptr, |
|
1722 png_ptr->background.red, gs); |
|
1723 |
|
1724 png_ptr->background.green = png_gamma_correct(png_ptr, |
|
1725 png_ptr->background.green, gs); |
|
1726 |
|
1727 png_ptr->background.blue = png_gamma_correct(png_ptr, |
|
1728 png_ptr->background.blue, gs); |
|
1729 } |
|
1730 |
|
1731 else |
|
1732 { |
|
1733 /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ |
|
1734 png_ptr->background_1.red = png_ptr->background_1.green |
|
1735 = png_ptr->background_1.blue = png_ptr->background_1.gray; |
|
1736 |
|
1737 png_ptr->background.red = png_ptr->background.green |
|
1738 = png_ptr->background.blue = png_ptr->background.gray; |
|
1739 } |
|
1740 } /* color_type != PNG_COLOR_TYPE_PALETTE */ |
|
1741 }/* png_ptr->transformations & PNG_BACKGROUND */ |
|
1742 |
|
1743 else |
|
1744 /* Transformation does not include PNG_BACKGROUND */ |
|
1745 #endif /* PNG_READ_BACKGROUND_SUPPORTED */ |
|
1746 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
1747 { |
|
1748 png_colorp palette = png_ptr->palette; |
|
1749 int num_palette = png_ptr->num_palette; |
|
1750 int i; |
|
1751 |
|
1752 /*NOTE: there are other transformations that should probably be in here |
|
1753 * too. |
|
1754 */ |
|
1755 for (i = 0; i < num_palette; i++) |
|
1756 { |
|
1757 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
|
1758 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
|
1759 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
|
1760 } |
|
1761 |
|
1762 /* Done the gamma correction. */ |
|
1763 png_ptr->transformations &= ~PNG_GAMMA; |
|
1764 } /* color_type == PALETTE && !PNG_BACKGROUND transformation */ |
|
1765 } |
|
1766 #ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
1767 else |
|
1768 #endif |
|
1769 #endif /* PNG_READ_GAMMA_SUPPORTED */ |
|
1770 |
|
1771 #ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
1772 /* No GAMMA transformation (see the hanging else 4 lines above) */ |
|
1773 if ((png_ptr->transformations & PNG_COMPOSE) && |
|
1774 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) |
|
1775 { |
|
1776 int i; |
|
1777 int istop = (int)png_ptr->num_trans; |
|
1778 png_color back; |
|
1779 png_colorp palette = png_ptr->palette; |
|
1780 |
|
1781 back.red = (png_byte)png_ptr->background.red; |
|
1782 back.green = (png_byte)png_ptr->background.green; |
|
1783 back.blue = (png_byte)png_ptr->background.blue; |
|
1784 |
|
1785 for (i = 0; i < istop; i++) |
|
1786 { |
|
1787 if (png_ptr->trans_alpha[i] == 0) |
|
1788 { |
|
1789 palette[i] = back; |
|
1790 } |
|
1791 |
|
1792 else if (png_ptr->trans_alpha[i] != 0xff) |
|
1793 { |
|
1794 /* The png_composite() macro is defined in png.h */ |
|
1795 png_composite(palette[i].red, palette[i].red, |
|
1796 png_ptr->trans_alpha[i], back.red); |
|
1797 |
|
1798 png_composite(palette[i].green, palette[i].green, |
|
1799 png_ptr->trans_alpha[i], back.green); |
|
1800 |
|
1801 png_composite(palette[i].blue, palette[i].blue, |
|
1802 png_ptr->trans_alpha[i], back.blue); |
|
1803 } |
|
1804 } |
|
1805 |
|
1806 png_ptr->transformations &= ~PNG_COMPOSE; |
|
1807 } |
|
1808 #endif /* PNG_READ_BACKGROUND_SUPPORTED */ |
|
1809 |
|
1810 #ifdef PNG_READ_SHIFT_SUPPORTED |
|
1811 if ((png_ptr->transformations & PNG_SHIFT) && |
|
1812 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) |
|
1813 { |
|
1814 png_uint_16 i; |
|
1815 png_uint_16 istop = png_ptr->num_palette; |
|
1816 int sr = 8 - png_ptr->sig_bit.red; |
|
1817 int sg = 8 - png_ptr->sig_bit.green; |
|
1818 int sb = 8 - png_ptr->sig_bit.blue; |
|
1819 |
|
1820 if (sr < 0 || sr > 8) |
|
1821 sr = 0; |
|
1822 |
|
1823 if (sg < 0 || sg > 8) |
|
1824 sg = 0; |
|
1825 |
|
1826 if (sb < 0 || sb > 8) |
|
1827 sb = 0; |
|
1828 |
|
1829 for (i = 0; i < istop; i++) |
|
1830 { |
|
1831 png_ptr->palette[i].red >>= sr; |
|
1832 png_ptr->palette[i].green >>= sg; |
|
1833 png_ptr->palette[i].blue >>= sb; |
|
1834 } |
|
1835 } |
|
1836 #endif /* PNG_READ_SHIFT_SUPPORTED */ |
|
1837 } |
|
1838 |
|
1839 /* Modify the info structure to reflect the transformations. The |
|
1840 * info should be updated so a PNG file could be written with it, |
|
1841 * assuming the transformations result in valid PNG data. |
|
1842 */ |
|
1843 void /* PRIVATE */ |
|
1844 png_read_transform_info(png_structp png_ptr, png_infop info_ptr) |
|
1845 { |
|
1846 png_debug(1, "in png_read_transform_info"); |
|
1847 |
|
1848 #ifdef PNG_READ_EXPAND_SUPPORTED |
|
1849 if (png_ptr->transformations & PNG_EXPAND) |
|
1850 { |
|
1851 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
1852 { |
|
1853 /* This check must match what actually happens in |
|
1854 * png_do_expand_palette; if it ever checks the tRNS chunk to see if |
|
1855 * it is all opaque we must do the same (at present it does not.) |
|
1856 */ |
|
1857 if (png_ptr->num_trans > 0) |
|
1858 info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
|
1859 |
|
1860 else |
|
1861 info_ptr->color_type = PNG_COLOR_TYPE_RGB; |
|
1862 |
|
1863 info_ptr->bit_depth = 8; |
|
1864 info_ptr->num_trans = 0; |
|
1865 |
|
1866 if (png_ptr->palette == NULL) |
|
1867 png_error (png_ptr, "Palette is NULL in indexed image"); |
|
1868 } |
|
1869 else |
|
1870 { |
|
1871 if (png_ptr->num_trans) |
|
1872 { |
|
1873 if (png_ptr->transformations & PNG_EXPAND_tRNS) |
|
1874 info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
|
1875 } |
|
1876 if (info_ptr->bit_depth < 8) |
|
1877 info_ptr->bit_depth = 8; |
|
1878 |
|
1879 info_ptr->num_trans = 0; |
|
1880 } |
|
1881 } |
|
1882 #endif |
|
1883 |
|
1884 #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ |
|
1885 defined(PNG_READ_ALPHA_MODE_SUPPORTED) |
|
1886 /* The following is almost certainly wrong unless the background value is in |
|
1887 * the screen space! |
|
1888 */ |
|
1889 if (png_ptr->transformations & PNG_COMPOSE) |
|
1890 info_ptr->background = png_ptr->background; |
|
1891 #endif |
|
1892 |
|
1893 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
1894 /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4), |
|
1895 * however it seems that the code in png_init_read_transformations, which has |
|
1896 * been called before this from png_read_update_info->png_read_start_row |
|
1897 * sometimes does the gamma transform and cancels the flag. |
|
1898 */ |
|
1899 info_ptr->gamma = png_ptr->gamma; |
|
1900 #endif |
|
1901 |
|
1902 if (info_ptr->bit_depth == 16) |
|
1903 { |
|
1904 # ifdef PNG_READ_16BIT_SUPPORTED |
|
1905 # ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED |
|
1906 if (png_ptr->transformations & PNG_SCALE_16_TO_8) |
|
1907 info_ptr->bit_depth = 8; |
|
1908 # endif |
|
1909 |
|
1910 # ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED |
|
1911 if (png_ptr->transformations & PNG_16_TO_8) |
|
1912 info_ptr->bit_depth = 8; |
|
1913 # endif |
|
1914 |
|
1915 # else |
|
1916 /* No 16 bit support: force chopping 16-bit input down to 8, in this case |
|
1917 * the app program can chose if both APIs are available by setting the |
|
1918 * correct scaling to use. |
|
1919 */ |
|
1920 # ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED |
|
1921 /* For compatibility with previous versions use the strip method by |
|
1922 * default. This code works because if PNG_SCALE_16_TO_8 is already |
|
1923 * set the code below will do that in preference to the chop. |
|
1924 */ |
|
1925 png_ptr->transformations |= PNG_16_TO_8; |
|
1926 info_ptr->bit_depth = 8; |
|
1927 # else |
|
1928 |
|
1929 # if PNG_READ_SCALE_16_TO_8_SUPPORTED |
|
1930 png_ptr->transformations |= PNG_SCALE_16_TO_8; |
|
1931 info_ptr->bit_depth = 8; |
|
1932 # else |
|
1933 |
|
1934 CONFIGURATION ERROR: you must enable at least one 16 to 8 method |
|
1935 # endif |
|
1936 # endif |
|
1937 #endif /* !READ_16BIT_SUPPORTED */ |
|
1938 } |
|
1939 |
|
1940 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
|
1941 if (png_ptr->transformations & PNG_GRAY_TO_RGB) |
|
1942 info_ptr->color_type |= PNG_COLOR_MASK_COLOR; |
|
1943 #endif |
|
1944 |
|
1945 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
|
1946 if (png_ptr->transformations & PNG_RGB_TO_GRAY) |
|
1947 info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR; |
|
1948 #endif |
|
1949 |
|
1950 #ifdef PNG_READ_QUANTIZE_SUPPORTED |
|
1951 if (png_ptr->transformations & PNG_QUANTIZE) |
|
1952 { |
|
1953 if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || |
|
1954 (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && |
|
1955 png_ptr->palette_lookup && info_ptr->bit_depth == 8) |
|
1956 { |
|
1957 info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; |
|
1958 } |
|
1959 } |
|
1960 #endif |
|
1961 |
|
1962 #ifdef PNG_READ_EXPAND_16_SUPPORTED |
|
1963 if (png_ptr->transformations & PNG_EXPAND_16 && info_ptr->bit_depth == 8 && |
|
1964 info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) |
|
1965 { |
|
1966 info_ptr->bit_depth = 16; |
|
1967 } |
|
1968 #endif |
|
1969 |
|
1970 #ifdef PNG_READ_PACK_SUPPORTED |
|
1971 if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8)) |
|
1972 info_ptr->bit_depth = 8; |
|
1973 #endif |
|
1974 |
|
1975 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
1976 info_ptr->channels = 1; |
|
1977 |
|
1978 else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR) |
|
1979 info_ptr->channels = 3; |
|
1980 |
|
1981 else |
|
1982 info_ptr->channels = 1; |
|
1983 |
|
1984 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
|
1985 if (png_ptr->transformations & PNG_STRIP_ALPHA) |
|
1986 { |
|
1987 info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; |
|
1988 info_ptr->num_trans = 0; |
|
1989 } |
|
1990 #endif |
|
1991 |
|
1992 if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) |
|
1993 info_ptr->channels++; |
|
1994 |
|
1995 #ifdef PNG_READ_FILLER_SUPPORTED |
|
1996 /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */ |
|
1997 if ((png_ptr->transformations & PNG_FILLER) && |
|
1998 ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || |
|
1999 (info_ptr->color_type == PNG_COLOR_TYPE_GRAY))) |
|
2000 { |
|
2001 info_ptr->channels++; |
|
2002 /* If adding a true alpha channel not just filler */ |
|
2003 if (png_ptr->transformations & PNG_ADD_ALPHA) |
|
2004 info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
|
2005 } |
|
2006 #endif |
|
2007 |
|
2008 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \ |
|
2009 defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
|
2010 if (png_ptr->transformations & PNG_USER_TRANSFORM) |
|
2011 { |
|
2012 if (info_ptr->bit_depth < png_ptr->user_transform_depth) |
|
2013 info_ptr->bit_depth = png_ptr->user_transform_depth; |
|
2014 |
|
2015 if (info_ptr->channels < png_ptr->user_transform_channels) |
|
2016 info_ptr->channels = png_ptr->user_transform_channels; |
|
2017 } |
|
2018 #endif |
|
2019 |
|
2020 info_ptr->pixel_depth = (png_byte)(info_ptr->channels * |
|
2021 info_ptr->bit_depth); |
|
2022 |
|
2023 info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width); |
|
2024 |
|
2025 /* Adding in 1.5.4: cache the above value in png_struct so that we can later |
|
2026 * check in png_rowbytes that the user buffer won't get overwritten. Note |
|
2027 * that the field is not always set - if png_read_update_info isn't called |
|
2028 * the application has to either not do any transforms or get the calculation |
|
2029 * right itself. |
|
2030 */ |
|
2031 png_ptr->info_rowbytes = info_ptr->rowbytes; |
|
2032 |
|
2033 #ifndef PNG_READ_EXPAND_SUPPORTED |
|
2034 if (png_ptr) |
|
2035 return; |
|
2036 #endif |
|
2037 } |
|
2038 |
|
2039 /* Transform the row. The order of transformations is significant, |
|
2040 * and is very touchy. If you add a transformation, take care to |
|
2041 * decide how it fits in with the other transformations here. |
|
2042 */ |
|
2043 void /* PRIVATE */ |
|
2044 png_do_read_transformations(png_structp png_ptr) |
|
2045 { |
|
2046 png_debug(1, "in png_do_read_transformations"); |
|
2047 |
|
2048 if (png_ptr->row_buf == NULL) |
|
2049 { |
|
2050 /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this |
|
2051 * error is incredibly rare and incredibly easy to debug without this |
|
2052 * information. |
|
2053 */ |
|
2054 png_error(png_ptr, "NULL row buffer"); |
|
2055 } |
|
2056 |
|
2057 /* The following is debugging; prior to 1.5.4 the code was never compiled in; |
|
2058 * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro |
|
2059 * PNG_WARN_UNINITIALIZED_ROW removed. In 1.5 the new flag is set only for |
|
2060 * selected new APIs to ensure that there is no API change. |
|
2061 */ |
|
2062 if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 && |
|
2063 !(png_ptr->flags & PNG_FLAG_ROW_INIT)) |
|
2064 { |
|
2065 /* Application has failed to call either png_read_start_image() or |
|
2066 * png_read_update_info() after setting transforms that expand pixels. |
|
2067 * This check added to libpng-1.2.19 (but not enabled until 1.5.4). |
|
2068 */ |
|
2069 png_error(png_ptr, "Uninitialized row"); |
|
2070 } |
|
2071 |
|
2072 #ifdef PNG_READ_EXPAND_SUPPORTED |
|
2073 if (png_ptr->transformations & PNG_EXPAND) |
|
2074 { |
|
2075 if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE) |
|
2076 { |
|
2077 png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
2078 png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans); |
|
2079 } |
|
2080 |
|
2081 else |
|
2082 { |
|
2083 if (png_ptr->num_trans && |
|
2084 (png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
2085 png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
2086 &(png_ptr->trans_color)); |
|
2087 |
|
2088 else |
|
2089 png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
2090 NULL); |
|
2091 } |
|
2092 } |
|
2093 #endif |
|
2094 |
|
2095 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
|
2096 if ((png_ptr->transformations & PNG_STRIP_ALPHA) && |
|
2097 !(png_ptr->transformations & PNG_COMPOSE) && |
|
2098 (png_ptr->row_info.color_type == PNG_COLOR_TYPE_RGB_ALPHA || |
|
2099 png_ptr->row_info.color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) |
|
2100 png_do_strip_channel(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
2101 0 /* at_start == false, because SWAP_ALPHA happens later */); |
|
2102 #endif |
|
2103 |
|
2104 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
|
2105 if (png_ptr->transformations & PNG_RGB_TO_GRAY) |
|
2106 { |
|
2107 int rgb_error = |
|
2108 png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), |
|
2109 png_ptr->row_buf + 1); |
|
2110 |
|
2111 if (rgb_error) |
|
2112 { |
|
2113 png_ptr->rgb_to_gray_status=1; |
|
2114 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == |
|
2115 PNG_RGB_TO_GRAY_WARN) |
|
2116 png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel"); |
|
2117 |
|
2118 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == |
|
2119 PNG_RGB_TO_GRAY_ERR) |
|
2120 png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel"); |
|
2121 } |
|
2122 } |
|
2123 #endif |
|
2124 |
|
2125 /* From Andreas Dilger e-mail to png-implement, 26 March 1998: |
|
2126 * |
|
2127 * In most cases, the "simple transparency" should be done prior to doing |
|
2128 * gray-to-RGB, or you will have to test 3x as many bytes to check if a |
|
2129 * pixel is transparent. You would also need to make sure that the |
|
2130 * transparency information is upgraded to RGB. |
|
2131 * |
|
2132 * To summarize, the current flow is: |
|
2133 * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite |
|
2134 * with background "in place" if transparent, |
|
2135 * convert to RGB if necessary |
|
2136 * - Gray + alpha -> composite with gray background and remove alpha bytes, |
|
2137 * convert to RGB if necessary |
|
2138 * |
|
2139 * To support RGB backgrounds for gray images we need: |
|
2140 * - Gray + simple transparency -> convert to RGB + simple transparency, |
|
2141 * compare 3 or 6 bytes and composite with |
|
2142 * background "in place" if transparent |
|
2143 * (3x compare/pixel compared to doing |
|
2144 * composite with gray bkgrnd) |
|
2145 * - Gray + alpha -> convert to RGB + alpha, composite with background and |
|
2146 * remove alpha bytes (3x float |
|
2147 * operations/pixel compared with composite |
|
2148 * on gray background) |
|
2149 * |
|
2150 * Greg's change will do this. The reason it wasn't done before is for |
|
2151 * performance, as this increases the per-pixel operations. If we would check |
|
2152 * in advance if the background was gray or RGB, and position the gray-to-RGB |
|
2153 * transform appropriately, then it would save a lot of work/time. |
|
2154 */ |
|
2155 |
|
2156 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
|
2157 /* If gray -> RGB, do so now only if background is non-gray; else do later |
|
2158 * for performance reasons |
|
2159 */ |
|
2160 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && |
|
2161 !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) |
|
2162 png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
2163 #endif |
|
2164 |
|
2165 #if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ |
|
2166 (defined PNG_READ_ALPHA_MODE_SUPPORTED) |
|
2167 if (png_ptr->transformations & PNG_COMPOSE) |
|
2168 png_do_compose(&(png_ptr->row_info), png_ptr->row_buf + 1, png_ptr); |
|
2169 #endif |
|
2170 |
|
2171 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
2172 if ((png_ptr->transformations & PNG_GAMMA) && |
|
2173 #if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ |
|
2174 (defined PNG_READ_ALPHA_MODE_SUPPORTED) |
|
2175 !((png_ptr->transformations & PNG_COMPOSE) && |
|
2176 ((png_ptr->num_trans != 0) || |
|
2177 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) && |
|
2178 #endif |
|
2179 (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) |
|
2180 png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1, png_ptr); |
|
2181 #endif |
|
2182 |
|
2183 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
|
2184 if ((png_ptr->transformations & PNG_STRIP_ALPHA) && |
|
2185 (png_ptr->transformations & PNG_COMPOSE) && |
|
2186 (png_ptr->row_info.color_type == PNG_COLOR_TYPE_RGB_ALPHA || |
|
2187 png_ptr->row_info.color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) |
|
2188 png_do_strip_channel(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
2189 0 /* at_start == false, because SWAP_ALPHA happens later */); |
|
2190 #endif |
|
2191 |
|
2192 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
2193 if ((png_ptr->transformations & PNG_ENCODE_ALPHA) && |
|
2194 (png_ptr->row_info.color_type & PNG_COLOR_MASK_ALPHA)) |
|
2195 png_do_encode_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1, png_ptr); |
|
2196 #endif |
|
2197 |
|
2198 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED |
|
2199 if (png_ptr->transformations & PNG_SCALE_16_TO_8) |
|
2200 png_do_scale_16_to_8(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
2201 #endif |
|
2202 |
|
2203 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED |
|
2204 /* There is no harm in doing both of these because only one has any effect, |
|
2205 * by putting the 'scale' option first if the app asks for scale (either by |
|
2206 * calling the API or in a TRANSFORM flag) this is what happens. |
|
2207 */ |
|
2208 if (png_ptr->transformations & PNG_16_TO_8) |
|
2209 png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
2210 #endif |
|
2211 |
|
2212 #ifdef PNG_READ_QUANTIZE_SUPPORTED |
|
2213 if (png_ptr->transformations & PNG_QUANTIZE) |
|
2214 { |
|
2215 png_do_quantize(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
2216 png_ptr->palette_lookup, png_ptr->quantize_index); |
|
2217 |
|
2218 if (png_ptr->row_info.rowbytes == 0) |
|
2219 png_error(png_ptr, "png_do_quantize returned rowbytes=0"); |
|
2220 } |
|
2221 #endif /* PNG_READ_QUANTIZE_SUPPORTED */ |
|
2222 |
|
2223 #ifdef PNG_READ_EXPAND_16_SUPPORTED |
|
2224 /* Do the expansion now, after all the arithmetic has been done. Notice |
|
2225 * that previous transformations can handle the PNG_EXPAND_16 flag if this |
|
2226 * is efficient (particularly true in the case of gamma correction, where |
|
2227 * better accuracy results faster!) |
|
2228 */ |
|
2229 if (png_ptr->transformations & PNG_EXPAND_16) |
|
2230 png_do_expand_16(&png_ptr->row_info, png_ptr->row_buf + 1); |
|
2231 #endif |
|
2232 |
|
2233 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
|
2234 /*NOTE: moved here in 1.5.4 (from much later in this list.) */ |
|
2235 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && |
|
2236 (png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) |
|
2237 png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
2238 #endif |
|
2239 |
|
2240 #ifdef PNG_READ_INVERT_SUPPORTED |
|
2241 if (png_ptr->transformations & PNG_INVERT_MONO) |
|
2242 png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
2243 #endif |
|
2244 |
|
2245 #ifdef PNG_READ_SHIFT_SUPPORTED |
|
2246 if (png_ptr->transformations & PNG_SHIFT) |
|
2247 png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
2248 &(png_ptr->shift)); |
|
2249 #endif |
|
2250 |
|
2251 #ifdef PNG_READ_PACK_SUPPORTED |
|
2252 if (png_ptr->transformations & PNG_PACK) |
|
2253 png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
2254 #endif |
|
2255 |
|
2256 #ifdef PNG_READ_BGR_SUPPORTED |
|
2257 if (png_ptr->transformations & PNG_BGR) |
|
2258 png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
2259 #endif |
|
2260 |
|
2261 #ifdef PNG_READ_PACKSWAP_SUPPORTED |
|
2262 if (png_ptr->transformations & PNG_PACKSWAP) |
|
2263 png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
2264 #endif |
|
2265 |
|
2266 #ifdef PNG_READ_FILLER_SUPPORTED |
|
2267 if (png_ptr->transformations & PNG_FILLER) |
|
2268 png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
2269 (png_uint_32)png_ptr->filler, png_ptr->flags); |
|
2270 #endif |
|
2271 |
|
2272 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED |
|
2273 if (png_ptr->transformations & PNG_INVERT_ALPHA) |
|
2274 png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
2275 #endif |
|
2276 |
|
2277 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED |
|
2278 if (png_ptr->transformations & PNG_SWAP_ALPHA) |
|
2279 png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
2280 #endif |
|
2281 |
|
2282 #ifdef PNG_READ_16BIT_SUPPORTED |
|
2283 #ifdef PNG_READ_SWAP_SUPPORTED |
|
2284 if (png_ptr->transformations & PNG_SWAP_BYTES) |
|
2285 png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
2286 #endif |
|
2287 #endif |
|
2288 |
|
2289 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED |
|
2290 if (png_ptr->transformations & PNG_USER_TRANSFORM) |
|
2291 { |
|
2292 if (png_ptr->read_user_transform_fn != NULL) |
|
2293 (*(png_ptr->read_user_transform_fn)) /* User read transform function */ |
|
2294 (png_ptr, /* png_ptr */ |
|
2295 &(png_ptr->row_info), /* row_info: */ |
|
2296 /* png_uint_32 width; width of row */ |
|
2297 /* png_size_t rowbytes; number of bytes in row */ |
|
2298 /* png_byte color_type; color type of pixels */ |
|
2299 /* png_byte bit_depth; bit depth of samples */ |
|
2300 /* png_byte channels; number of channels (1-4) */ |
|
2301 /* png_byte pixel_depth; bits per pixel (depth*channels) */ |
|
2302 png_ptr->row_buf + 1); /* start of pixel data for row */ |
|
2303 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED |
|
2304 if (png_ptr->user_transform_depth) |
|
2305 png_ptr->row_info.bit_depth = png_ptr->user_transform_depth; |
|
2306 |
|
2307 if (png_ptr->user_transform_channels) |
|
2308 png_ptr->row_info.channels = png_ptr->user_transform_channels; |
|
2309 #endif |
|
2310 png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth * |
|
2311 png_ptr->row_info.channels); |
|
2312 |
|
2313 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, |
|
2314 png_ptr->row_info.width); |
|
2315 } |
|
2316 #endif |
|
2317 } |
|
2318 |
|
2319 #ifdef PNG_READ_PACK_SUPPORTED |
|
2320 /* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, |
|
2321 * without changing the actual values. Thus, if you had a row with |
|
2322 * a bit depth of 1, you would end up with bytes that only contained |
|
2323 * the numbers 0 or 1. If you would rather they contain 0 and 255, use |
|
2324 * png_do_shift() after this. |
|
2325 */ |
|
2326 void /* PRIVATE */ |
|
2327 png_do_unpack(png_row_infop row_info, png_bytep row) |
|
2328 { |
|
2329 png_debug(1, "in png_do_unpack"); |
|
2330 |
|
2331 if (row_info->bit_depth < 8) |
|
2332 { |
|
2333 png_uint_32 i; |
|
2334 png_uint_32 row_width=row_info->width; |
|
2335 |
|
2336 switch (row_info->bit_depth) |
|
2337 { |
|
2338 case 1: |
|
2339 { |
|
2340 png_bytep sp = row + (png_size_t)((row_width - 1) >> 3); |
|
2341 png_bytep dp = row + (png_size_t)row_width - 1; |
|
2342 png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07); |
|
2343 for (i = 0; i < row_width; i++) |
|
2344 { |
|
2345 *dp = (png_byte)((*sp >> shift) & 0x01); |
|
2346 |
|
2347 if (shift == 7) |
|
2348 { |
|
2349 shift = 0; |
|
2350 sp--; |
|
2351 } |
|
2352 |
|
2353 else |
|
2354 shift++; |
|
2355 |
|
2356 dp--; |
|
2357 } |
|
2358 break; |
|
2359 } |
|
2360 |
|
2361 case 2: |
|
2362 { |
|
2363 |
|
2364 png_bytep sp = row + (png_size_t)((row_width - 1) >> 2); |
|
2365 png_bytep dp = row + (png_size_t)row_width - 1; |
|
2366 png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
|
2367 for (i = 0; i < row_width; i++) |
|
2368 { |
|
2369 *dp = (png_byte)((*sp >> shift) & 0x03); |
|
2370 |
|
2371 if (shift == 6) |
|
2372 { |
|
2373 shift = 0; |
|
2374 sp--; |
|
2375 } |
|
2376 |
|
2377 else |
|
2378 shift += 2; |
|
2379 |
|
2380 dp--; |
|
2381 } |
|
2382 break; |
|
2383 } |
|
2384 |
|
2385 case 4: |
|
2386 { |
|
2387 png_bytep sp = row + (png_size_t)((row_width - 1) >> 1); |
|
2388 png_bytep dp = row + (png_size_t)row_width - 1; |
|
2389 png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); |
|
2390 for (i = 0; i < row_width; i++) |
|
2391 { |
|
2392 *dp = (png_byte)((*sp >> shift) & 0x0f); |
|
2393 |
|
2394 if (shift == 4) |
|
2395 { |
|
2396 shift = 0; |
|
2397 sp--; |
|
2398 } |
|
2399 |
|
2400 else |
|
2401 shift = 4; |
|
2402 |
|
2403 dp--; |
|
2404 } |
|
2405 break; |
|
2406 } |
|
2407 |
|
2408 default: |
|
2409 break; |
|
2410 } |
|
2411 row_info->bit_depth = 8; |
|
2412 row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
|
2413 row_info->rowbytes = row_width * row_info->channels; |
|
2414 } |
|
2415 } |
|
2416 #endif |
|
2417 |
|
2418 #ifdef PNG_READ_SHIFT_SUPPORTED |
|
2419 /* Reverse the effects of png_do_shift. This routine merely shifts the |
|
2420 * pixels back to their significant bits values. Thus, if you have |
|
2421 * a row of bit depth 8, but only 5 are significant, this will shift |
|
2422 * the values back to 0 through 31. |
|
2423 */ |
|
2424 void /* PRIVATE */ |
|
2425 png_do_unshift(png_row_infop row_info, png_bytep row, |
|
2426 png_const_color_8p sig_bits) |
|
2427 { |
|
2428 png_debug(1, "in png_do_unshift"); |
|
2429 |
|
2430 if ( |
|
2431 row_info->color_type != PNG_COLOR_TYPE_PALETTE) |
|
2432 { |
|
2433 int shift[4]; |
|
2434 int channels = 0; |
|
2435 int c; |
|
2436 png_uint_16 value = 0; |
|
2437 png_uint_32 row_width = row_info->width; |
|
2438 |
|
2439 if (row_info->color_type & PNG_COLOR_MASK_COLOR) |
|
2440 { |
|
2441 shift[channels++] = row_info->bit_depth - sig_bits->red; |
|
2442 shift[channels++] = row_info->bit_depth - sig_bits->green; |
|
2443 shift[channels++] = row_info->bit_depth - sig_bits->blue; |
|
2444 } |
|
2445 |
|
2446 else |
|
2447 { |
|
2448 shift[channels++] = row_info->bit_depth - sig_bits->gray; |
|
2449 } |
|
2450 |
|
2451 if (row_info->color_type & PNG_COLOR_MASK_ALPHA) |
|
2452 { |
|
2453 shift[channels++] = row_info->bit_depth - sig_bits->alpha; |
|
2454 } |
|
2455 |
|
2456 for (c = 0; c < channels; c++) |
|
2457 { |
|
2458 if (shift[c] <= 0) |
|
2459 shift[c] = 0; |
|
2460 |
|
2461 else |
|
2462 value = 1; |
|
2463 } |
|
2464 |
|
2465 if (!value) |
|
2466 return; |
|
2467 |
|
2468 switch (row_info->bit_depth) |
|
2469 { |
|
2470 default: |
|
2471 break; |
|
2472 |
|
2473 case 2: |
|
2474 { |
|
2475 png_bytep bp; |
|
2476 png_size_t i; |
|
2477 png_size_t istop = row_info->rowbytes; |
|
2478 |
|
2479 for (bp = row, i = 0; i < istop; i++) |
|
2480 { |
|
2481 *bp >>= 1; |
|
2482 *bp++ &= 0x55; |
|
2483 } |
|
2484 break; |
|
2485 } |
|
2486 |
|
2487 case 4: |
|
2488 { |
|
2489 png_bytep bp = row; |
|
2490 png_size_t i; |
|
2491 png_size_t istop = row_info->rowbytes; |
|
2492 png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) | |
|
2493 (png_byte)((int)0xf >> shift[0])); |
|
2494 |
|
2495 for (i = 0; i < istop; i++) |
|
2496 { |
|
2497 *bp >>= shift[0]; |
|
2498 *bp++ &= mask; |
|
2499 } |
|
2500 break; |
|
2501 } |
|
2502 |
|
2503 case 8: |
|
2504 { |
|
2505 png_bytep bp = row; |
|
2506 png_uint_32 i; |
|
2507 png_uint_32 istop = row_width * channels; |
|
2508 |
|
2509 for (i = 0; i < istop; i++) |
|
2510 { |
|
2511 *bp++ >>= shift[i%channels]; |
|
2512 } |
|
2513 break; |
|
2514 } |
|
2515 |
|
2516 #ifdef PNG_READ_16BIT_SUPPORTED |
|
2517 case 16: |
|
2518 { |
|
2519 png_bytep bp = row; |
|
2520 png_uint_32 i; |
|
2521 png_uint_32 istop = channels * row_width; |
|
2522 |
|
2523 for (i = 0; i < istop; i++) |
|
2524 { |
|
2525 value = (png_uint_16)((*bp << 8) + *(bp + 1)); |
|
2526 value >>= shift[i%channels]; |
|
2527 *bp++ = (png_byte)(value >> 8); |
|
2528 *bp++ = (png_byte)(value & 0xff); |
|
2529 } |
|
2530 break; |
|
2531 } |
|
2532 #endif |
|
2533 } |
|
2534 } |
|
2535 } |
|
2536 #endif |
|
2537 |
|
2538 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED |
|
2539 /* Scale rows of bit depth 16 down to 8 accurately */ |
|
2540 void /* PRIVATE */ |
|
2541 png_do_scale_16_to_8(png_row_infop row_info, png_bytep row) |
|
2542 { |
|
2543 png_debug(1, "in png_do_scale_16_to_8"); |
|
2544 |
|
2545 if (row_info->bit_depth == 16) |
|
2546 { |
|
2547 png_bytep sp = row; /* source */ |
|
2548 png_bytep dp = row; /* destinaton */ |
|
2549 png_bytep ep = sp + row_info->rowbytes; /* end+1 */ |
|
2550 |
|
2551 while (sp < ep) |
|
2552 { |
|
2553 /* The input is an array of 16 bit components, these must be scaled to |
|
2554 * 8 bits each. For a 16 bit value V the required value (from the PNG |
|
2555 * specification) is: |
|
2556 * |
|
2557 * (V * 255) / 65535 |
|
2558 * |
|
2559 * This reduces to round(V / 257), or floor((V + 128.5)/257) |
|
2560 * |
|
2561 * Represent V as the two byte value vhi.vlo. Make a guess that the |
|
2562 * result is the top byte of V, vhi, then the correction to this value |
|
2563 * is: |
|
2564 * |
|
2565 * error = floor(((V-vhi.vhi) + 128.5) / 257) |
|
2566 * = floor(((vlo-vhi) + 128.5) / 257) |
|
2567 * |
|
2568 * This can be approximated using integer arithmetic (and a signed |
|
2569 * shift): |
|
2570 * |
|
2571 * error = (vlo-vhi+128) >> 8; |
|
2572 * |
|
2573 * The approximate differs from the exact answer only when (vlo-vhi) is |
|
2574 * 128; it then gives a correction of +1 when the exact correction is |
|
2575 * 0. This gives 128 errors. The exact answer (correct for all 16 bit |
|
2576 * input values) is: |
|
2577 * |
|
2578 * error = (vlo-vhi+128)*65535 >> 24; |
|
2579 * |
|
2580 * An alternative arithmetic calculation which also gives no errors is: |
|
2581 * |
|
2582 * (V * 255 + 32895) >> 16 |
|
2583 */ |
|
2584 |
|
2585 png_int_32 tmp = *sp++; /* must be signed! */ |
|
2586 tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24; |
|
2587 *dp++ = (png_byte)tmp; |
|
2588 } |
|
2589 |
|
2590 row_info->bit_depth = 8; |
|
2591 row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
|
2592 row_info->rowbytes = row_info->width * row_info->channels; |
|
2593 } |
|
2594 } |
|
2595 #endif |
|
2596 |
|
2597 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED |
|
2598 void /* PRIVATE */ |
|
2599 /* Simply discard the low byte. This was the default behavior prior |
|
2600 * to libpng-1.5.4. |
|
2601 */ |
|
2602 png_do_chop(png_row_infop row_info, png_bytep row) |
|
2603 { |
|
2604 png_debug(1, "in png_do_chop"); |
|
2605 |
|
2606 if (row_info->bit_depth == 16) |
|
2607 { |
|
2608 png_bytep sp = row; /* source */ |
|
2609 png_bytep dp = row; /* destinaton */ |
|
2610 png_bytep ep = sp + row_info->rowbytes; /* end+1 */ |
|
2611 |
|
2612 while (sp < ep) |
|
2613 { |
|
2614 *dp++ = *sp; |
|
2615 sp += 2; /* skip low byte */ |
|
2616 } |
|
2617 |
|
2618 row_info->bit_depth = 8; |
|
2619 row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
|
2620 row_info->rowbytes = row_info->width * row_info->channels; |
|
2621 } |
|
2622 } |
|
2623 #endif |
|
2624 |
|
2625 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED |
|
2626 void /* PRIVATE */ |
|
2627 png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) |
|
2628 { |
|
2629 png_debug(1, "in png_do_read_swap_alpha"); |
|
2630 |
|
2631 { |
|
2632 png_uint_32 row_width = row_info->width; |
|
2633 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
2634 { |
|
2635 /* This converts from RGBA to ARGB */ |
|
2636 if (row_info->bit_depth == 8) |
|
2637 { |
|
2638 png_bytep sp = row + row_info->rowbytes; |
|
2639 png_bytep dp = sp; |
|
2640 png_byte save; |
|
2641 png_uint_32 i; |
|
2642 |
|
2643 for (i = 0; i < row_width; i++) |
|
2644 { |
|
2645 save = *(--sp); |
|
2646 *(--dp) = *(--sp); |
|
2647 *(--dp) = *(--sp); |
|
2648 *(--dp) = *(--sp); |
|
2649 *(--dp) = save; |
|
2650 } |
|
2651 } |
|
2652 |
|
2653 #ifdef PNG_READ_16BIT_SUPPORTED |
|
2654 /* This converts from RRGGBBAA to AARRGGBB */ |
|
2655 else |
|
2656 { |
|
2657 png_bytep sp = row + row_info->rowbytes; |
|
2658 png_bytep dp = sp; |
|
2659 png_byte save[2]; |
|
2660 png_uint_32 i; |
|
2661 |
|
2662 for (i = 0; i < row_width; i++) |
|
2663 { |
|
2664 save[0] = *(--sp); |
|
2665 save[1] = *(--sp); |
|
2666 *(--dp) = *(--sp); |
|
2667 *(--dp) = *(--sp); |
|
2668 *(--dp) = *(--sp); |
|
2669 *(--dp) = *(--sp); |
|
2670 *(--dp) = *(--sp); |
|
2671 *(--dp) = *(--sp); |
|
2672 *(--dp) = save[0]; |
|
2673 *(--dp) = save[1]; |
|
2674 } |
|
2675 } |
|
2676 #endif |
|
2677 } |
|
2678 |
|
2679 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
2680 { |
|
2681 /* This converts from GA to AG */ |
|
2682 if (row_info->bit_depth == 8) |
|
2683 { |
|
2684 png_bytep sp = row + row_info->rowbytes; |
|
2685 png_bytep dp = sp; |
|
2686 png_byte save; |
|
2687 png_uint_32 i; |
|
2688 |
|
2689 for (i = 0; i < row_width; i++) |
|
2690 { |
|
2691 save = *(--sp); |
|
2692 *(--dp) = *(--sp); |
|
2693 *(--dp) = save; |
|
2694 } |
|
2695 } |
|
2696 |
|
2697 #ifdef PNG_READ_16BIT_SUPPORTED |
|
2698 /* This converts from GGAA to AAGG */ |
|
2699 else |
|
2700 { |
|
2701 png_bytep sp = row + row_info->rowbytes; |
|
2702 png_bytep dp = sp; |
|
2703 png_byte save[2]; |
|
2704 png_uint_32 i; |
|
2705 |
|
2706 for (i = 0; i < row_width; i++) |
|
2707 { |
|
2708 save[0] = *(--sp); |
|
2709 save[1] = *(--sp); |
|
2710 *(--dp) = *(--sp); |
|
2711 *(--dp) = *(--sp); |
|
2712 *(--dp) = save[0]; |
|
2713 *(--dp) = save[1]; |
|
2714 } |
|
2715 } |
|
2716 #endif |
|
2717 } |
|
2718 } |
|
2719 } |
|
2720 #endif |
|
2721 |
|
2722 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED |
|
2723 void /* PRIVATE */ |
|
2724 png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) |
|
2725 { |
|
2726 png_uint_32 row_width; |
|
2727 png_debug(1, "in png_do_read_invert_alpha"); |
|
2728 |
|
2729 row_width = row_info->width; |
|
2730 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
2731 { |
|
2732 if (row_info->bit_depth == 8) |
|
2733 { |
|
2734 /* This inverts the alpha channel in RGBA */ |
|
2735 png_bytep sp = row + row_info->rowbytes; |
|
2736 png_bytep dp = sp; |
|
2737 png_uint_32 i; |
|
2738 |
|
2739 for (i = 0; i < row_width; i++) |
|
2740 { |
|
2741 *(--dp) = (png_byte)(255 - *(--sp)); |
|
2742 |
|
2743 /* This does nothing: |
|
2744 *(--dp) = *(--sp); |
|
2745 *(--dp) = *(--sp); |
|
2746 *(--dp) = *(--sp); |
|
2747 We can replace it with: |
|
2748 */ |
|
2749 sp-=3; |
|
2750 dp=sp; |
|
2751 } |
|
2752 } |
|
2753 |
|
2754 #ifdef PNG_READ_16BIT_SUPPORTED |
|
2755 /* This inverts the alpha channel in RRGGBBAA */ |
|
2756 else |
|
2757 { |
|
2758 png_bytep sp = row + row_info->rowbytes; |
|
2759 png_bytep dp = sp; |
|
2760 png_uint_32 i; |
|
2761 |
|
2762 for (i = 0; i < row_width; i++) |
|
2763 { |
|
2764 *(--dp) = (png_byte)(255 - *(--sp)); |
|
2765 *(--dp) = (png_byte)(255 - *(--sp)); |
|
2766 |
|
2767 /* This does nothing: |
|
2768 *(--dp) = *(--sp); |
|
2769 *(--dp) = *(--sp); |
|
2770 *(--dp) = *(--sp); |
|
2771 *(--dp) = *(--sp); |
|
2772 *(--dp) = *(--sp); |
|
2773 *(--dp) = *(--sp); |
|
2774 We can replace it with: |
|
2775 */ |
|
2776 sp-=6; |
|
2777 dp=sp; |
|
2778 } |
|
2779 } |
|
2780 #endif |
|
2781 } |
|
2782 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
2783 { |
|
2784 if (row_info->bit_depth == 8) |
|
2785 { |
|
2786 /* This inverts the alpha channel in GA */ |
|
2787 png_bytep sp = row + row_info->rowbytes; |
|
2788 png_bytep dp = sp; |
|
2789 png_uint_32 i; |
|
2790 |
|
2791 for (i = 0; i < row_width; i++) |
|
2792 { |
|
2793 *(--dp) = (png_byte)(255 - *(--sp)); |
|
2794 *(--dp) = *(--sp); |
|
2795 } |
|
2796 } |
|
2797 |
|
2798 #ifdef PNG_READ_16BIT_SUPPORTED |
|
2799 else |
|
2800 { |
|
2801 /* This inverts the alpha channel in GGAA */ |
|
2802 png_bytep sp = row + row_info->rowbytes; |
|
2803 png_bytep dp = sp; |
|
2804 png_uint_32 i; |
|
2805 |
|
2806 for (i = 0; i < row_width; i++) |
|
2807 { |
|
2808 *(--dp) = (png_byte)(255 - *(--sp)); |
|
2809 *(--dp) = (png_byte)(255 - *(--sp)); |
|
2810 /* |
|
2811 *(--dp) = *(--sp); |
|
2812 *(--dp) = *(--sp); |
|
2813 */ |
|
2814 sp-=2; |
|
2815 dp=sp; |
|
2816 } |
|
2817 } |
|
2818 #endif |
|
2819 } |
|
2820 } |
|
2821 #endif |
|
2822 |
|
2823 #ifdef PNG_READ_FILLER_SUPPORTED |
|
2824 /* Add filler channel if we have RGB color */ |
|
2825 void /* PRIVATE */ |
|
2826 png_do_read_filler(png_row_infop row_info, png_bytep row, |
|
2827 png_uint_32 filler, png_uint_32 flags) |
|
2828 { |
|
2829 png_uint_32 i; |
|
2830 png_uint_32 row_width = row_info->width; |
|
2831 |
|
2832 #ifdef PNG_READ_16BIT_SUPPORTED |
|
2833 png_byte hi_filler = (png_byte)((filler>>8) & 0xff); |
|
2834 #endif |
|
2835 png_byte lo_filler = (png_byte)(filler & 0xff); |
|
2836 |
|
2837 png_debug(1, "in png_do_read_filler"); |
|
2838 |
|
2839 if ( |
|
2840 row_info->color_type == PNG_COLOR_TYPE_GRAY) |
|
2841 { |
|
2842 if (row_info->bit_depth == 8) |
|
2843 { |
|
2844 if (flags & PNG_FLAG_FILLER_AFTER) |
|
2845 { |
|
2846 /* This changes the data from G to GX */ |
|
2847 png_bytep sp = row + (png_size_t)row_width; |
|
2848 png_bytep dp = sp + (png_size_t)row_width; |
|
2849 for (i = 1; i < row_width; i++) |
|
2850 { |
|
2851 *(--dp) = lo_filler; |
|
2852 *(--dp) = *(--sp); |
|
2853 } |
|
2854 *(--dp) = lo_filler; |
|
2855 row_info->channels = 2; |
|
2856 row_info->pixel_depth = 16; |
|
2857 row_info->rowbytes = row_width * 2; |
|
2858 } |
|
2859 |
|
2860 else |
|
2861 { |
|
2862 /* This changes the data from G to XG */ |
|
2863 png_bytep sp = row + (png_size_t)row_width; |
|
2864 png_bytep dp = sp + (png_size_t)row_width; |
|
2865 for (i = 0; i < row_width; i++) |
|
2866 { |
|
2867 *(--dp) = *(--sp); |
|
2868 *(--dp) = lo_filler; |
|
2869 } |
|
2870 row_info->channels = 2; |
|
2871 row_info->pixel_depth = 16; |
|
2872 row_info->rowbytes = row_width * 2; |
|
2873 } |
|
2874 } |
|
2875 |
|
2876 #ifdef PNG_READ_16BIT_SUPPORTED |
|
2877 else if (row_info->bit_depth == 16) |
|
2878 { |
|
2879 if (flags & PNG_FLAG_FILLER_AFTER) |
|
2880 { |
|
2881 /* This changes the data from GG to GGXX */ |
|
2882 png_bytep sp = row + (png_size_t)row_width * 2; |
|
2883 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2884 for (i = 1; i < row_width; i++) |
|
2885 { |
|
2886 *(--dp) = hi_filler; |
|
2887 *(--dp) = lo_filler; |
|
2888 *(--dp) = *(--sp); |
|
2889 *(--dp) = *(--sp); |
|
2890 } |
|
2891 *(--dp) = hi_filler; |
|
2892 *(--dp) = lo_filler; |
|
2893 row_info->channels = 2; |
|
2894 row_info->pixel_depth = 32; |
|
2895 row_info->rowbytes = row_width * 4; |
|
2896 } |
|
2897 |
|
2898 else |
|
2899 { |
|
2900 /* This changes the data from GG to XXGG */ |
|
2901 png_bytep sp = row + (png_size_t)row_width * 2; |
|
2902 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2903 for (i = 0; i < row_width; i++) |
|
2904 { |
|
2905 *(--dp) = *(--sp); |
|
2906 *(--dp) = *(--sp); |
|
2907 *(--dp) = hi_filler; |
|
2908 *(--dp) = lo_filler; |
|
2909 } |
|
2910 row_info->channels = 2; |
|
2911 row_info->pixel_depth = 32; |
|
2912 row_info->rowbytes = row_width * 4; |
|
2913 } |
|
2914 } |
|
2915 #endif |
|
2916 } /* COLOR_TYPE == GRAY */ |
|
2917 else if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
|
2918 { |
|
2919 if (row_info->bit_depth == 8) |
|
2920 { |
|
2921 if (flags & PNG_FLAG_FILLER_AFTER) |
|
2922 { |
|
2923 /* This changes the data from RGB to RGBX */ |
|
2924 png_bytep sp = row + (png_size_t)row_width * 3; |
|
2925 png_bytep dp = sp + (png_size_t)row_width; |
|
2926 for (i = 1; i < row_width; i++) |
|
2927 { |
|
2928 *(--dp) = lo_filler; |
|
2929 *(--dp) = *(--sp); |
|
2930 *(--dp) = *(--sp); |
|
2931 *(--dp) = *(--sp); |
|
2932 } |
|
2933 *(--dp) = lo_filler; |
|
2934 row_info->channels = 4; |
|
2935 row_info->pixel_depth = 32; |
|
2936 row_info->rowbytes = row_width * 4; |
|
2937 } |
|
2938 |
|
2939 else |
|
2940 { |
|
2941 /* This changes the data from RGB to XRGB */ |
|
2942 png_bytep sp = row + (png_size_t)row_width * 3; |
|
2943 png_bytep dp = sp + (png_size_t)row_width; |
|
2944 for (i = 0; i < row_width; i++) |
|
2945 { |
|
2946 *(--dp) = *(--sp); |
|
2947 *(--dp) = *(--sp); |
|
2948 *(--dp) = *(--sp); |
|
2949 *(--dp) = lo_filler; |
|
2950 } |
|
2951 row_info->channels = 4; |
|
2952 row_info->pixel_depth = 32; |
|
2953 row_info->rowbytes = row_width * 4; |
|
2954 } |
|
2955 } |
|
2956 |
|
2957 #ifdef PNG_READ_16BIT_SUPPORTED |
|
2958 else if (row_info->bit_depth == 16) |
|
2959 { |
|
2960 if (flags & PNG_FLAG_FILLER_AFTER) |
|
2961 { |
|
2962 /* This changes the data from RRGGBB to RRGGBBXX */ |
|
2963 png_bytep sp = row + (png_size_t)row_width * 6; |
|
2964 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2965 for (i = 1; i < row_width; i++) |
|
2966 { |
|
2967 *(--dp) = hi_filler; |
|
2968 *(--dp) = lo_filler; |
|
2969 *(--dp) = *(--sp); |
|
2970 *(--dp) = *(--sp); |
|
2971 *(--dp) = *(--sp); |
|
2972 *(--dp) = *(--sp); |
|
2973 *(--dp) = *(--sp); |
|
2974 *(--dp) = *(--sp); |
|
2975 } |
|
2976 *(--dp) = hi_filler; |
|
2977 *(--dp) = lo_filler; |
|
2978 row_info->channels = 4; |
|
2979 row_info->pixel_depth = 64; |
|
2980 row_info->rowbytes = row_width * 8; |
|
2981 } |
|
2982 |
|
2983 else |
|
2984 { |
|
2985 /* This changes the data from RRGGBB to XXRRGGBB */ |
|
2986 png_bytep sp = row + (png_size_t)row_width * 6; |
|
2987 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2988 for (i = 0; i < row_width; i++) |
|
2989 { |
|
2990 *(--dp) = *(--sp); |
|
2991 *(--dp) = *(--sp); |
|
2992 *(--dp) = *(--sp); |
|
2993 *(--dp) = *(--sp); |
|
2994 *(--dp) = *(--sp); |
|
2995 *(--dp) = *(--sp); |
|
2996 *(--dp) = hi_filler; |
|
2997 *(--dp) = lo_filler; |
|
2998 } |
|
2999 |
|
3000 row_info->channels = 4; |
|
3001 row_info->pixel_depth = 64; |
|
3002 row_info->rowbytes = row_width * 8; |
|
3003 } |
|
3004 } |
|
3005 #endif |
|
3006 } /* COLOR_TYPE == RGB */ |
|
3007 } |
|
3008 #endif |
|
3009 |
|
3010 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
|
3011 /* Expand grayscale files to RGB, with or without alpha */ |
|
3012 void /* PRIVATE */ |
|
3013 png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) |
|
3014 { |
|
3015 png_uint_32 i; |
|
3016 png_uint_32 row_width = row_info->width; |
|
3017 |
|
3018 png_debug(1, "in png_do_gray_to_rgb"); |
|
3019 |
|
3020 if (row_info->bit_depth >= 8 && |
|
3021 !(row_info->color_type & PNG_COLOR_MASK_COLOR)) |
|
3022 { |
|
3023 if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
|
3024 { |
|
3025 if (row_info->bit_depth == 8) |
|
3026 { |
|
3027 /* This changes G to RGB */ |
|
3028 png_bytep sp = row + (png_size_t)row_width - 1; |
|
3029 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
3030 for (i = 0; i < row_width; i++) |
|
3031 { |
|
3032 *(dp--) = *sp; |
|
3033 *(dp--) = *sp; |
|
3034 *(dp--) = *(sp--); |
|
3035 } |
|
3036 } |
|
3037 |
|
3038 else |
|
3039 { |
|
3040 /* This changes GG to RRGGBB */ |
|
3041 png_bytep sp = row + (png_size_t)row_width * 2 - 1; |
|
3042 png_bytep dp = sp + (png_size_t)row_width * 4; |
|
3043 for (i = 0; i < row_width; i++) |
|
3044 { |
|
3045 *(dp--) = *sp; |
|
3046 *(dp--) = *(sp - 1); |
|
3047 *(dp--) = *sp; |
|
3048 *(dp--) = *(sp - 1); |
|
3049 *(dp--) = *(sp--); |
|
3050 *(dp--) = *(sp--); |
|
3051 } |
|
3052 } |
|
3053 } |
|
3054 |
|
3055 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
3056 { |
|
3057 if (row_info->bit_depth == 8) |
|
3058 { |
|
3059 /* This changes GA to RGBA */ |
|
3060 png_bytep sp = row + (png_size_t)row_width * 2 - 1; |
|
3061 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
3062 for (i = 0; i < row_width; i++) |
|
3063 { |
|
3064 *(dp--) = *(sp--); |
|
3065 *(dp--) = *sp; |
|
3066 *(dp--) = *sp; |
|
3067 *(dp--) = *(sp--); |
|
3068 } |
|
3069 } |
|
3070 |
|
3071 else |
|
3072 { |
|
3073 /* This changes GGAA to RRGGBBAA */ |
|
3074 png_bytep sp = row + (png_size_t)row_width * 4 - 1; |
|
3075 png_bytep dp = sp + (png_size_t)row_width * 4; |
|
3076 for (i = 0; i < row_width; i++) |
|
3077 { |
|
3078 *(dp--) = *(sp--); |
|
3079 *(dp--) = *(sp--); |
|
3080 *(dp--) = *sp; |
|
3081 *(dp--) = *(sp - 1); |
|
3082 *(dp--) = *sp; |
|
3083 *(dp--) = *(sp - 1); |
|
3084 *(dp--) = *(sp--); |
|
3085 *(dp--) = *(sp--); |
|
3086 } |
|
3087 } |
|
3088 } |
|
3089 row_info->channels += (png_byte)2; |
|
3090 row_info->color_type |= PNG_COLOR_MASK_COLOR; |
|
3091 row_info->pixel_depth = (png_byte)(row_info->channels * |
|
3092 row_info->bit_depth); |
|
3093 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
3094 } |
|
3095 } |
|
3096 #endif |
|
3097 |
|
3098 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
|
3099 /* Reduce RGB files to grayscale, with or without alpha |
|
3100 * using the equation given in Poynton's ColorFAQ at |
|
3101 * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008) |
|
3102 * New link: |
|
3103 * <http://www.poynton.com/notes/colour_and_gamma/> |
|
3104 * Charles Poynton poynton at poynton.com |
|
3105 * |
|
3106 * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B |
|
3107 * |
|
3108 * We approximate this with |
|
3109 * |
|
3110 * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B |
|
3111 * |
|
3112 * which can be expressed with integers as |
|
3113 * |
|
3114 * Y = (6969 * R + 23434 * G + 2365 * B)/32768 |
|
3115 * |
|
3116 * The calculation is to be done in a linear colorspace. |
|
3117 * |
|
3118 * Other integer coefficents can be used via png_set_rgb_to_gray(). |
|
3119 */ |
|
3120 int /* PRIVATE */ |
|
3121 png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) |
|
3122 |
|
3123 { |
|
3124 png_uint_32 i; |
|
3125 |
|
3126 png_uint_32 row_width = row_info->width; |
|
3127 int rgb_error = 0; |
|
3128 |
|
3129 png_debug(1, "in png_do_rgb_to_gray"); |
|
3130 |
|
3131 if (!(row_info->color_type & PNG_COLOR_MASK_PALETTE) && |
|
3132 (row_info->color_type & PNG_COLOR_MASK_COLOR)) |
|
3133 { |
|
3134 png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; |
|
3135 png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; |
|
3136 png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff; |
|
3137 |
|
3138 if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
|
3139 { |
|
3140 if (row_info->bit_depth == 8) |
|
3141 { |
|
3142 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
3143 if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
|
3144 { |
|
3145 png_bytep sp = row; |
|
3146 png_bytep dp = row; |
|
3147 |
|
3148 for (i = 0; i < row_width; i++) |
|
3149 { |
|
3150 png_byte red = png_ptr->gamma_to_1[*(sp++)]; |
|
3151 png_byte green = png_ptr->gamma_to_1[*(sp++)]; |
|
3152 png_byte blue = png_ptr->gamma_to_1[*(sp++)]; |
|
3153 |
|
3154 if (red != green || red != blue) |
|
3155 { |
|
3156 rgb_error |= 1; |
|
3157 *(dp++) = png_ptr->gamma_from_1[ |
|
3158 (rc*red + gc*green + bc*blue)>>15]; |
|
3159 } |
|
3160 |
|
3161 else |
|
3162 *(dp++) = *(sp - 1); |
|
3163 } |
|
3164 } |
|
3165 else |
|
3166 #endif |
|
3167 { |
|
3168 png_bytep sp = row; |
|
3169 png_bytep dp = row; |
|
3170 for (i = 0; i < row_width; i++) |
|
3171 { |
|
3172 png_byte red = *(sp++); |
|
3173 png_byte green = *(sp++); |
|
3174 png_byte blue = *(sp++); |
|
3175 |
|
3176 if (red != green || red != blue) |
|
3177 { |
|
3178 rgb_error |= 1; |
|
3179 *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); |
|
3180 } |
|
3181 |
|
3182 else |
|
3183 *(dp++) = *(sp - 1); |
|
3184 } |
|
3185 } |
|
3186 } |
|
3187 |
|
3188 else /* RGB bit_depth == 16 */ |
|
3189 { |
|
3190 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
3191 if (png_ptr->gamma_16_to_1 != NULL && |
|
3192 png_ptr->gamma_16_from_1 != NULL) |
|
3193 { |
|
3194 png_bytep sp = row; |
|
3195 png_bytep dp = row; |
|
3196 for (i = 0; i < row_width; i++) |
|
3197 { |
|
3198 png_uint_16 red, green, blue, w; |
|
3199 |
|
3200 red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; |
|
3201 green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; |
|
3202 blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; |
|
3203 |
|
3204 if (red == green && red == blue) |
|
3205 w = red; |
|
3206 |
|
3207 else |
|
3208 { |
|
3209 png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) |
|
3210 >> png_ptr->gamma_shift][red>>8]; |
|
3211 png_uint_16 green_1 = |
|
3212 png_ptr->gamma_16_to_1[(green&0xff) >> |
|
3213 png_ptr->gamma_shift][green>>8]; |
|
3214 png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) |
|
3215 >> png_ptr->gamma_shift][blue>>8]; |
|
3216 png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 |
|
3217 + bc*blue_1)>>15); |
|
3218 w = png_ptr->gamma_16_from_1[(gray16&0xff) >> |
|
3219 png_ptr->gamma_shift][gray16 >> 8]; |
|
3220 rgb_error |= 1; |
|
3221 } |
|
3222 |
|
3223 *(dp++) = (png_byte)((w>>8) & 0xff); |
|
3224 *(dp++) = (png_byte)(w & 0xff); |
|
3225 } |
|
3226 } |
|
3227 else |
|
3228 #endif |
|
3229 { |
|
3230 png_bytep sp = row; |
|
3231 png_bytep dp = row; |
|
3232 for (i = 0; i < row_width; i++) |
|
3233 { |
|
3234 png_uint_16 red, green, blue, gray16; |
|
3235 |
|
3236 red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; |
|
3237 green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; |
|
3238 blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; |
|
3239 |
|
3240 if (red != green || red != blue) |
|
3241 rgb_error |= 1; |
|
3242 |
|
3243 gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); |
|
3244 *(dp++) = (png_byte)((gray16>>8) & 0xff); |
|
3245 *(dp++) = (png_byte)(gray16 & 0xff); |
|
3246 } |
|
3247 } |
|
3248 } |
|
3249 } |
|
3250 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
3251 { |
|
3252 if (row_info->bit_depth == 8) |
|
3253 { |
|
3254 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
3255 if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
|
3256 { |
|
3257 png_bytep sp = row; |
|
3258 png_bytep dp = row; |
|
3259 for (i = 0; i < row_width; i++) |
|
3260 { |
|
3261 png_byte red = png_ptr->gamma_to_1[*(sp++)]; |
|
3262 png_byte green = png_ptr->gamma_to_1[*(sp++)]; |
|
3263 png_byte blue = png_ptr->gamma_to_1[*(sp++)]; |
|
3264 |
|
3265 if (red != green || red != blue) |
|
3266 rgb_error |= 1; |
|
3267 |
|
3268 *(dp++) = png_ptr->gamma_from_1 |
|
3269 [(rc*red + gc*green + bc*blue)>>15]; |
|
3270 |
|
3271 *(dp++) = *(sp++); /* alpha */ |
|
3272 } |
|
3273 } |
|
3274 else |
|
3275 #endif |
|
3276 { |
|
3277 png_bytep sp = row; |
|
3278 png_bytep dp = row; |
|
3279 for (i = 0; i < row_width; i++) |
|
3280 { |
|
3281 png_byte red = *(sp++); |
|
3282 png_byte green = *(sp++); |
|
3283 png_byte blue = *(sp++); |
|
3284 if (red != green || red != blue) |
|
3285 rgb_error |= 1; |
|
3286 |
|
3287 *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); |
|
3288 *(dp++) = *(sp++); /* alpha */ |
|
3289 } |
|
3290 } |
|
3291 } |
|
3292 else /* RGBA bit_depth == 16 */ |
|
3293 { |
|
3294 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
3295 if (png_ptr->gamma_16_to_1 != NULL && |
|
3296 png_ptr->gamma_16_from_1 != NULL) |
|
3297 { |
|
3298 png_bytep sp = row; |
|
3299 png_bytep dp = row; |
|
3300 for (i = 0; i < row_width; i++) |
|
3301 { |
|
3302 png_uint_16 red, green, blue, w; |
|
3303 |
|
3304 red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; |
|
3305 green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; |
|
3306 blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; |
|
3307 |
|
3308 if (red == green && red == blue) |
|
3309 w = red; |
|
3310 |
|
3311 else |
|
3312 { |
|
3313 png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> |
|
3314 png_ptr->gamma_shift][red>>8]; |
|
3315 |
|
3316 png_uint_16 green_1 = |
|
3317 png_ptr->gamma_16_to_1[(green&0xff) >> |
|
3318 png_ptr->gamma_shift][green>>8]; |
|
3319 |
|
3320 png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> |
|
3321 png_ptr->gamma_shift][blue>>8]; |
|
3322 |
|
3323 png_uint_16 gray16 = (png_uint_16)((rc * red_1 |
|
3324 + gc * green_1 + bc * blue_1)>>15); |
|
3325 |
|
3326 w = png_ptr->gamma_16_from_1[(gray16&0xff) >> |
|
3327 png_ptr->gamma_shift][gray16 >> 8]; |
|
3328 |
|
3329 rgb_error |= 1; |
|
3330 } |
|
3331 |
|
3332 *(dp++) = (png_byte)((w>>8) & 0xff); |
|
3333 *(dp++) = (png_byte)(w & 0xff); |
|
3334 *(dp++) = *(sp++); /* alpha */ |
|
3335 *(dp++) = *(sp++); |
|
3336 } |
|
3337 } |
|
3338 else |
|
3339 #endif |
|
3340 { |
|
3341 png_bytep sp = row; |
|
3342 png_bytep dp = row; |
|
3343 for (i = 0; i < row_width; i++) |
|
3344 { |
|
3345 png_uint_16 red, green, blue, gray16; |
|
3346 red = (png_uint_16)((*(sp)<<8) | *(sp + 1)); sp += 2; |
|
3347 green = (png_uint_16)((*(sp)<<8) | *(sp + 1)); sp += 2; |
|
3348 blue = (png_uint_16)((*(sp)<<8) | *(sp + 1)); sp += 2; |
|
3349 |
|
3350 if (red != green || red != blue) |
|
3351 rgb_error |= 1; |
|
3352 |
|
3353 gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); |
|
3354 *(dp++) = (png_byte)((gray16>>8) & 0xff); |
|
3355 *(dp++) = (png_byte)(gray16 & 0xff); |
|
3356 *(dp++) = *(sp++); /* alpha */ |
|
3357 *(dp++) = *(sp++); |
|
3358 } |
|
3359 } |
|
3360 } |
|
3361 } |
|
3362 row_info->channels -= 2; |
|
3363 row_info->color_type = (png_byte)(row_info->color_type & |
|
3364 ~PNG_COLOR_MASK_COLOR); |
|
3365 row_info->pixel_depth = (png_byte)(row_info->channels * |
|
3366 row_info->bit_depth); |
|
3367 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
3368 } |
|
3369 return rgb_error; |
|
3370 } |
|
3371 #endif |
|
3372 #endif /* PNG_READ_TRANSFORMS_SUPPORTED */ |
|
3373 |
|
3374 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED |
|
3375 /* Build a grayscale palette. Palette is assumed to be 1 << bit_depth |
|
3376 * large of png_color. This lets grayscale images be treated as |
|
3377 * paletted. Most useful for gamma correction and simplification |
|
3378 * of code. This API is not used internally. |
|
3379 */ |
|
3380 void PNGAPI |
|
3381 png_build_grayscale_palette(int bit_depth, png_colorp palette) |
|
3382 { |
|
3383 int num_palette; |
|
3384 int color_inc; |
|
3385 int i; |
|
3386 int v; |
|
3387 |
|
3388 png_debug(1, "in png_do_build_grayscale_palette"); |
|
3389 |
|
3390 if (palette == NULL) |
|
3391 return; |
|
3392 |
|
3393 switch (bit_depth) |
|
3394 { |
|
3395 case 1: |
|
3396 num_palette = 2; |
|
3397 color_inc = 0xff; |
|
3398 break; |
|
3399 |
|
3400 case 2: |
|
3401 num_palette = 4; |
|
3402 color_inc = 0x55; |
|
3403 break; |
|
3404 |
|
3405 case 4: |
|
3406 num_palette = 16; |
|
3407 color_inc = 0x11; |
|
3408 break; |
|
3409 |
|
3410 case 8: |
|
3411 num_palette = 256; |
|
3412 color_inc = 1; |
|
3413 break; |
|
3414 |
|
3415 default: |
|
3416 num_palette = 0; |
|
3417 color_inc = 0; |
|
3418 break; |
|
3419 } |
|
3420 |
|
3421 for (i = 0, v = 0; i < num_palette; i++, v += color_inc) |
|
3422 { |
|
3423 palette[i].red = (png_byte)v; |
|
3424 palette[i].green = (png_byte)v; |
|
3425 palette[i].blue = (png_byte)v; |
|
3426 } |
|
3427 } |
|
3428 #endif |
|
3429 |
|
3430 |
|
3431 #ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
3432 #ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
3433 /* Replace any alpha or transparency with the supplied background color. |
|
3434 * "background" is already in the screen gamma, while "background_1" is |
|
3435 * at a gamma of 1.0. Paletted files have already been taken care of. |
|
3436 */ |
|
3437 void /* PRIVATE */ |
|
3438 png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr) |
|
3439 { |
|
3440 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
3441 png_const_bytep gamma_table = png_ptr->gamma_table; |
|
3442 png_const_bytep gamma_from_1 = png_ptr->gamma_from_1; |
|
3443 png_const_bytep gamma_to_1 = png_ptr->gamma_to_1; |
|
3444 png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table; |
|
3445 png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1; |
|
3446 png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1; |
|
3447 int gamma_shift = png_ptr->gamma_shift; |
|
3448 #endif |
|
3449 |
|
3450 png_bytep sp; |
|
3451 png_uint_32 i; |
|
3452 png_uint_32 row_width = row_info->width; |
|
3453 int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0; |
|
3454 int shift; |
|
3455 |
|
3456 png_debug(1, "in png_do_compose"); |
|
3457 |
|
3458 { |
|
3459 switch (row_info->color_type) |
|
3460 { |
|
3461 case PNG_COLOR_TYPE_GRAY: |
|
3462 { |
|
3463 switch (row_info->bit_depth) |
|
3464 { |
|
3465 case 1: |
|
3466 { |
|
3467 sp = row; |
|
3468 shift = 7; |
|
3469 for (i = 0; i < row_width; i++) |
|
3470 { |
|
3471 if ((png_uint_16)((*sp >> shift) & 0x01) |
|
3472 == png_ptr->trans_color.gray) |
|
3473 { |
|
3474 *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); |
|
3475 *sp |= (png_byte)(png_ptr->background.gray << shift); |
|
3476 } |
|
3477 |
|
3478 if (!shift) |
|
3479 { |
|
3480 shift = 7; |
|
3481 sp++; |
|
3482 } |
|
3483 |
|
3484 else |
|
3485 shift--; |
|
3486 } |
|
3487 break; |
|
3488 } |
|
3489 |
|
3490 case 2: |
|
3491 { |
|
3492 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
3493 if (gamma_table != NULL) |
|
3494 { |
|
3495 sp = row; |
|
3496 shift = 6; |
|
3497 for (i = 0; i < row_width; i++) |
|
3498 { |
|
3499 if ((png_uint_16)((*sp >> shift) & 0x03) |
|
3500 == png_ptr->trans_color.gray) |
|
3501 { |
|
3502 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
|
3503 *sp |= (png_byte)(png_ptr->background.gray << shift); |
|
3504 } |
|
3505 |
|
3506 else |
|
3507 { |
|
3508 png_byte p = (png_byte)((*sp >> shift) & 0x03); |
|
3509 png_byte g = (png_byte)((gamma_table [p | (p << 2) | |
|
3510 (p << 4) | (p << 6)] >> 6) & 0x03); |
|
3511 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
|
3512 *sp |= (png_byte)(g << shift); |
|
3513 } |
|
3514 |
|
3515 if (!shift) |
|
3516 { |
|
3517 shift = 6; |
|
3518 sp++; |
|
3519 } |
|
3520 |
|
3521 else |
|
3522 shift -= 2; |
|
3523 } |
|
3524 } |
|
3525 |
|
3526 else |
|
3527 #endif |
|
3528 { |
|
3529 sp = row; |
|
3530 shift = 6; |
|
3531 for (i = 0; i < row_width; i++) |
|
3532 { |
|
3533 if ((png_uint_16)((*sp >> shift) & 0x03) |
|
3534 == png_ptr->trans_color.gray) |
|
3535 { |
|
3536 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
|
3537 *sp |= (png_byte)(png_ptr->background.gray << shift); |
|
3538 } |
|
3539 |
|
3540 if (!shift) |
|
3541 { |
|
3542 shift = 6; |
|
3543 sp++; |
|
3544 } |
|
3545 |
|
3546 else |
|
3547 shift -= 2; |
|
3548 } |
|
3549 } |
|
3550 break; |
|
3551 } |
|
3552 |
|
3553 case 4: |
|
3554 { |
|
3555 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
3556 if (gamma_table != NULL) |
|
3557 { |
|
3558 sp = row; |
|
3559 shift = 4; |
|
3560 for (i = 0; i < row_width; i++) |
|
3561 { |
|
3562 if ((png_uint_16)((*sp >> shift) & 0x0f) |
|
3563 == png_ptr->trans_color.gray) |
|
3564 { |
|
3565 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
|
3566 *sp |= (png_byte)(png_ptr->background.gray << shift); |
|
3567 } |
|
3568 |
|
3569 else |
|
3570 { |
|
3571 png_byte p = (png_byte)((*sp >> shift) & 0x0f); |
|
3572 png_byte g = (png_byte)((gamma_table[p | |
|
3573 (p << 4)] >> 4) & 0x0f); |
|
3574 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
|
3575 *sp |= (png_byte)(g << shift); |
|
3576 } |
|
3577 |
|
3578 if (!shift) |
|
3579 { |
|
3580 shift = 4; |
|
3581 sp++; |
|
3582 } |
|
3583 |
|
3584 else |
|
3585 shift -= 4; |
|
3586 } |
|
3587 } |
|
3588 |
|
3589 else |
|
3590 #endif |
|
3591 { |
|
3592 sp = row; |
|
3593 shift = 4; |
|
3594 for (i = 0; i < row_width; i++) |
|
3595 { |
|
3596 if ((png_uint_16)((*sp >> shift) & 0x0f) |
|
3597 == png_ptr->trans_color.gray) |
|
3598 { |
|
3599 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
|
3600 *sp |= (png_byte)(png_ptr->background.gray << shift); |
|
3601 } |
|
3602 |
|
3603 if (!shift) |
|
3604 { |
|
3605 shift = 4; |
|
3606 sp++; |
|
3607 } |
|
3608 |
|
3609 else |
|
3610 shift -= 4; |
|
3611 } |
|
3612 } |
|
3613 break; |
|
3614 } |
|
3615 |
|
3616 case 8: |
|
3617 { |
|
3618 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
3619 if (gamma_table != NULL) |
|
3620 { |
|
3621 sp = row; |
|
3622 for (i = 0; i < row_width; i++, sp++) |
|
3623 { |
|
3624 if (*sp == png_ptr->trans_color.gray) |
|
3625 *sp = (png_byte)png_ptr->background.gray; |
|
3626 |
|
3627 else |
|
3628 *sp = gamma_table[*sp]; |
|
3629 } |
|
3630 } |
|
3631 else |
|
3632 #endif |
|
3633 { |
|
3634 sp = row; |
|
3635 for (i = 0; i < row_width; i++, sp++) |
|
3636 { |
|
3637 if (*sp == png_ptr->trans_color.gray) |
|
3638 *sp = (png_byte)png_ptr->background.gray; |
|
3639 } |
|
3640 } |
|
3641 break; |
|
3642 } |
|
3643 |
|
3644 case 16: |
|
3645 { |
|
3646 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
3647 if (gamma_16 != NULL) |
|
3648 { |
|
3649 sp = row; |
|
3650 for (i = 0; i < row_width; i++, sp += 2) |
|
3651 { |
|
3652 png_uint_16 v; |
|
3653 |
|
3654 v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
3655 |
|
3656 if (v == png_ptr->trans_color.gray) |
|
3657 { |
|
3658 /* Background is already in screen gamma */ |
|
3659 *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff); |
|
3660 *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); |
|
3661 } |
|
3662 |
|
3663 else |
|
3664 { |
|
3665 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
|
3666 *sp = (png_byte)((v >> 8) & 0xff); |
|
3667 *(sp + 1) = (png_byte)(v & 0xff); |
|
3668 } |
|
3669 } |
|
3670 } |
|
3671 else |
|
3672 #endif |
|
3673 { |
|
3674 sp = row; |
|
3675 for (i = 0; i < row_width; i++, sp += 2) |
|
3676 { |
|
3677 png_uint_16 v; |
|
3678 |
|
3679 v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
3680 |
|
3681 if (v == png_ptr->trans_color.gray) |
|
3682 { |
|
3683 *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff); |
|
3684 *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); |
|
3685 } |
|
3686 } |
|
3687 } |
|
3688 break; |
|
3689 } |
|
3690 |
|
3691 default: |
|
3692 break; |
|
3693 } |
|
3694 break; |
|
3695 } |
|
3696 |
|
3697 case PNG_COLOR_TYPE_RGB: |
|
3698 { |
|
3699 if (row_info->bit_depth == 8) |
|
3700 { |
|
3701 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
3702 if (gamma_table != NULL) |
|
3703 { |
|
3704 sp = row; |
|
3705 for (i = 0; i < row_width; i++, sp += 3) |
|
3706 { |
|
3707 if (*sp == png_ptr->trans_color.red && |
|
3708 *(sp + 1) == png_ptr->trans_color.green && |
|
3709 *(sp + 2) == png_ptr->trans_color.blue) |
|
3710 { |
|
3711 *sp = (png_byte)png_ptr->background.red; |
|
3712 *(sp + 1) = (png_byte)png_ptr->background.green; |
|
3713 *(sp + 2) = (png_byte)png_ptr->background.blue; |
|
3714 } |
|
3715 |
|
3716 else |
|
3717 { |
|
3718 *sp = gamma_table[*sp]; |
|
3719 *(sp + 1) = gamma_table[*(sp + 1)]; |
|
3720 *(sp + 2) = gamma_table[*(sp + 2)]; |
|
3721 } |
|
3722 } |
|
3723 } |
|
3724 else |
|
3725 #endif |
|
3726 { |
|
3727 sp = row; |
|
3728 for (i = 0; i < row_width; i++, sp += 3) |
|
3729 { |
|
3730 if (*sp == png_ptr->trans_color.red && |
|
3731 *(sp + 1) == png_ptr->trans_color.green && |
|
3732 *(sp + 2) == png_ptr->trans_color.blue) |
|
3733 { |
|
3734 *sp = (png_byte)png_ptr->background.red; |
|
3735 *(sp + 1) = (png_byte)png_ptr->background.green; |
|
3736 *(sp + 2) = (png_byte)png_ptr->background.blue; |
|
3737 } |
|
3738 } |
|
3739 } |
|
3740 } |
|
3741 else /* if (row_info->bit_depth == 16) */ |
|
3742 { |
|
3743 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
3744 if (gamma_16 != NULL) |
|
3745 { |
|
3746 sp = row; |
|
3747 for (i = 0; i < row_width; i++, sp += 6) |
|
3748 { |
|
3749 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
3750 |
|
3751 png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) |
|
3752 + *(sp + 3)); |
|
3753 |
|
3754 png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) |
|
3755 + *(sp + 5)); |
|
3756 |
|
3757 if (r == png_ptr->trans_color.red && |
|
3758 g == png_ptr->trans_color.green && |
|
3759 b == png_ptr->trans_color.blue) |
|
3760 { |
|
3761 /* Background is already in screen gamma */ |
|
3762 *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); |
|
3763 *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); |
|
3764 *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff); |
|
3765 *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff); |
|
3766 *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff); |
|
3767 *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); |
|
3768 } |
|
3769 |
|
3770 else |
|
3771 { |
|
3772 png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
|
3773 *sp = (png_byte)((v >> 8) & 0xff); |
|
3774 *(sp + 1) = (png_byte)(v & 0xff); |
|
3775 |
|
3776 v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
|
3777 *(sp + 2) = (png_byte)((v >> 8) & 0xff); |
|
3778 *(sp + 3) = (png_byte)(v & 0xff); |
|
3779 |
|
3780 v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
|
3781 *(sp + 4) = (png_byte)((v >> 8) & 0xff); |
|
3782 *(sp + 5) = (png_byte)(v & 0xff); |
|
3783 } |
|
3784 } |
|
3785 } |
|
3786 |
|
3787 else |
|
3788 #endif |
|
3789 { |
|
3790 sp = row; |
|
3791 for (i = 0; i < row_width; i++, sp += 6) |
|
3792 { |
|
3793 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
3794 |
|
3795 png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) |
|
3796 + *(sp + 3)); |
|
3797 |
|
3798 png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) |
|
3799 + *(sp + 5)); |
|
3800 |
|
3801 if (r == png_ptr->trans_color.red && |
|
3802 g == png_ptr->trans_color.green && |
|
3803 b == png_ptr->trans_color.blue) |
|
3804 { |
|
3805 *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); |
|
3806 *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); |
|
3807 *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff); |
|
3808 *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff); |
|
3809 *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff); |
|
3810 *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); |
|
3811 } |
|
3812 } |
|
3813 } |
|
3814 } |
|
3815 break; |
|
3816 } |
|
3817 |
|
3818 case PNG_COLOR_TYPE_GRAY_ALPHA: |
|
3819 { |
|
3820 if (row_info->bit_depth == 8) |
|
3821 { |
|
3822 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
3823 if (gamma_to_1 != NULL && gamma_from_1 != NULL && |
|
3824 gamma_table != NULL) |
|
3825 { |
|
3826 sp = row; |
|
3827 for (i = 0; i < row_width; i++, sp += 2) |
|
3828 { |
|
3829 png_uint_16 a = *(sp + 1); |
|
3830 |
|
3831 if (a == 0xff) |
|
3832 *sp = gamma_table[*sp]; |
|
3833 |
|
3834 else if (a == 0) |
|
3835 { |
|
3836 /* Background is already in screen gamma */ |
|
3837 *sp = (png_byte)png_ptr->background.gray; |
|
3838 } |
|
3839 |
|
3840 else |
|
3841 { |
|
3842 png_byte v, w; |
|
3843 |
|
3844 v = gamma_to_1[*sp]; |
|
3845 png_composite(w, v, a, png_ptr->background_1.gray); |
|
3846 if (!optimize) |
|
3847 w = gamma_from_1[w]; |
|
3848 *sp = w; |
|
3849 } |
|
3850 } |
|
3851 } |
|
3852 else |
|
3853 #endif |
|
3854 { |
|
3855 sp = row; |
|
3856 for (i = 0; i < row_width; i++, sp += 2) |
|
3857 { |
|
3858 png_byte a = *(sp + 1); |
|
3859 |
|
3860 if (a == 0) |
|
3861 *sp = (png_byte)png_ptr->background.gray; |
|
3862 |
|
3863 else if (a < 0xff) |
|
3864 png_composite(*sp, *sp, a, png_ptr->background_1.gray); |
|
3865 } |
|
3866 } |
|
3867 } |
|
3868 else /* if (png_ptr->bit_depth == 16) */ |
|
3869 { |
|
3870 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
3871 if (gamma_16 != NULL && gamma_16_from_1 != NULL && |
|
3872 gamma_16_to_1 != NULL) |
|
3873 { |
|
3874 sp = row; |
|
3875 for (i = 0; i < row_width; i++, sp += 4) |
|
3876 { |
|
3877 png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) |
|
3878 + *(sp + 3)); |
|
3879 |
|
3880 if (a == (png_uint_16)0xffff) |
|
3881 { |
|
3882 png_uint_16 v; |
|
3883 |
|
3884 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
|
3885 *sp = (png_byte)((v >> 8) & 0xff); |
|
3886 *(sp + 1) = (png_byte)(v & 0xff); |
|
3887 } |
|
3888 |
|
3889 else if (a == 0) |
|
3890 { |
|
3891 /* Background is already in screen gamma */ |
|
3892 *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff); |
|
3893 *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); |
|
3894 } |
|
3895 |
|
3896 else |
|
3897 { |
|
3898 png_uint_16 g, v, w; |
|
3899 |
|
3900 g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; |
|
3901 png_composite_16(v, g, a, png_ptr->background_1.gray); |
|
3902 if (optimize) |
|
3903 w = v; |
|
3904 else |
|
3905 w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8]; |
|
3906 *sp = (png_byte)((w >> 8) & 0xff); |
|
3907 *(sp + 1) = (png_byte)(w & 0xff); |
|
3908 } |
|
3909 } |
|
3910 } |
|
3911 else |
|
3912 #endif |
|
3913 { |
|
3914 sp = row; |
|
3915 for (i = 0; i < row_width; i++, sp += 4) |
|
3916 { |
|
3917 png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) |
|
3918 + *(sp + 3)); |
|
3919 |
|
3920 if (a == 0) |
|
3921 { |
|
3922 *sp = (png_byte)((png_ptr->background.gray >> 8) & 0xff); |
|
3923 *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); |
|
3924 } |
|
3925 |
|
3926 else if (a < 0xffff) |
|
3927 { |
|
3928 png_uint_16 g, v; |
|
3929 |
|
3930 g = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
3931 png_composite_16(v, g, a, png_ptr->background_1.gray); |
|
3932 *sp = (png_byte)((v >> 8) & 0xff); |
|
3933 *(sp + 1) = (png_byte)(v & 0xff); |
|
3934 } |
|
3935 } |
|
3936 } |
|
3937 } |
|
3938 break; |
|
3939 } |
|
3940 |
|
3941 case PNG_COLOR_TYPE_RGB_ALPHA: |
|
3942 { |
|
3943 if (row_info->bit_depth == 8) |
|
3944 { |
|
3945 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
3946 if (gamma_to_1 != NULL && gamma_from_1 != NULL && |
|
3947 gamma_table != NULL) |
|
3948 { |
|
3949 sp = row; |
|
3950 for (i = 0; i < row_width; i++, sp += 4) |
|
3951 { |
|
3952 png_byte a = *(sp + 3); |
|
3953 |
|
3954 if (a == 0xff) |
|
3955 { |
|
3956 *sp = gamma_table[*sp]; |
|
3957 *(sp + 1) = gamma_table[*(sp + 1)]; |
|
3958 *(sp + 2) = gamma_table[*(sp + 2)]; |
|
3959 } |
|
3960 |
|
3961 else if (a == 0) |
|
3962 { |
|
3963 /* Background is already in screen gamma */ |
|
3964 *sp = (png_byte)png_ptr->background.red; |
|
3965 *(sp + 1) = (png_byte)png_ptr->background.green; |
|
3966 *(sp + 2) = (png_byte)png_ptr->background.blue; |
|
3967 } |
|
3968 |
|
3969 else |
|
3970 { |
|
3971 png_byte v, w; |
|
3972 |
|
3973 v = gamma_to_1[*sp]; |
|
3974 png_composite(w, v, a, png_ptr->background_1.red); |
|
3975 if (!optimize) w = gamma_from_1[w]; |
|
3976 *sp = w; |
|
3977 |
|
3978 v = gamma_to_1[*(sp + 1)]; |
|
3979 png_composite(w, v, a, png_ptr->background_1.green); |
|
3980 if (!optimize) w = gamma_from_1[w]; |
|
3981 *(sp + 1) = w; |
|
3982 |
|
3983 v = gamma_to_1[*(sp + 2)]; |
|
3984 png_composite(w, v, a, png_ptr->background_1.blue); |
|
3985 if (!optimize) w = gamma_from_1[w]; |
|
3986 *(sp + 2) = w; |
|
3987 } |
|
3988 } |
|
3989 } |
|
3990 else |
|
3991 #endif |
|
3992 { |
|
3993 sp = row; |
|
3994 for (i = 0; i < row_width; i++, sp += 4) |
|
3995 { |
|
3996 png_byte a = *(sp + 3); |
|
3997 |
|
3998 if (a == 0) |
|
3999 { |
|
4000 *sp = (png_byte)png_ptr->background.red; |
|
4001 *(sp + 1) = (png_byte)png_ptr->background.green; |
|
4002 *(sp + 2) = (png_byte)png_ptr->background.blue; |
|
4003 } |
|
4004 |
|
4005 else if (a < 0xff) |
|
4006 { |
|
4007 png_composite(*sp, *sp, a, png_ptr->background.red); |
|
4008 |
|
4009 png_composite(*(sp + 1), *(sp + 1), a, |
|
4010 png_ptr->background.green); |
|
4011 |
|
4012 png_composite(*(sp + 2), *(sp + 2), a, |
|
4013 png_ptr->background.blue); |
|
4014 } |
|
4015 } |
|
4016 } |
|
4017 } |
|
4018 else /* if (row_info->bit_depth == 16) */ |
|
4019 { |
|
4020 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
4021 if (gamma_16 != NULL && gamma_16_from_1 != NULL && |
|
4022 gamma_16_to_1 != NULL) |
|
4023 { |
|
4024 sp = row; |
|
4025 for (i = 0; i < row_width; i++, sp += 8) |
|
4026 { |
|
4027 png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) |
|
4028 << 8) + (png_uint_16)(*(sp + 7))); |
|
4029 |
|
4030 if (a == (png_uint_16)0xffff) |
|
4031 { |
|
4032 png_uint_16 v; |
|
4033 |
|
4034 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
|
4035 *sp = (png_byte)((v >> 8) & 0xff); |
|
4036 *(sp + 1) = (png_byte)(v & 0xff); |
|
4037 |
|
4038 v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
|
4039 *(sp + 2) = (png_byte)((v >> 8) & 0xff); |
|
4040 *(sp + 3) = (png_byte)(v & 0xff); |
|
4041 |
|
4042 v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
|
4043 *(sp + 4) = (png_byte)((v >> 8) & 0xff); |
|
4044 *(sp + 5) = (png_byte)(v & 0xff); |
|
4045 } |
|
4046 |
|
4047 else if (a == 0) |
|
4048 { |
|
4049 /* Background is already in screen gamma */ |
|
4050 *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); |
|
4051 *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); |
|
4052 *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff); |
|
4053 *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff); |
|
4054 *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff); |
|
4055 *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); |
|
4056 } |
|
4057 |
|
4058 else |
|
4059 { |
|
4060 png_uint_16 v, w; |
|
4061 |
|
4062 v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; |
|
4063 png_composite_16(w, v, a, png_ptr->background_1.red); |
|
4064 if (!optimize) |
|
4065 w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; |
|
4066 *sp = (png_byte)((w >> 8) & 0xff); |
|
4067 *(sp + 1) = (png_byte)(w & 0xff); |
|
4068 |
|
4069 v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
|
4070 png_composite_16(w, v, a, png_ptr->background_1.green); |
|
4071 if (!optimize) |
|
4072 w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; |
|
4073 |
|
4074 *(sp + 2) = (png_byte)((w >> 8) & 0xff); |
|
4075 *(sp + 3) = (png_byte)(w & 0xff); |
|
4076 |
|
4077 v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
|
4078 png_composite_16(w, v, a, png_ptr->background_1.blue); |
|
4079 if (!optimize) |
|
4080 w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; |
|
4081 |
|
4082 *(sp + 4) = (png_byte)((w >> 8) & 0xff); |
|
4083 *(sp + 5) = (png_byte)(w & 0xff); |
|
4084 } |
|
4085 } |
|
4086 } |
|
4087 |
|
4088 else |
|
4089 #endif |
|
4090 { |
|
4091 sp = row; |
|
4092 for (i = 0; i < row_width; i++, sp += 8) |
|
4093 { |
|
4094 png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) |
|
4095 << 8) + (png_uint_16)(*(sp + 7))); |
|
4096 |
|
4097 if (a == 0) |
|
4098 { |
|
4099 *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); |
|
4100 *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); |
|
4101 *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) & 0xff); |
|
4102 *(sp + 3) = (png_byte)(png_ptr->background.green & 0xff); |
|
4103 *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) & 0xff); |
|
4104 *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); |
|
4105 } |
|
4106 |
|
4107 else if (a < 0xffff) |
|
4108 { |
|
4109 png_uint_16 v; |
|
4110 |
|
4111 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
4112 png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) |
|
4113 + *(sp + 3)); |
|
4114 png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) |
|
4115 + *(sp + 5)); |
|
4116 |
|
4117 png_composite_16(v, r, a, png_ptr->background.red); |
|
4118 *sp = (png_byte)((v >> 8) & 0xff); |
|
4119 *(sp + 1) = (png_byte)(v & 0xff); |
|
4120 |
|
4121 png_composite_16(v, g, a, png_ptr->background.green); |
|
4122 *(sp + 2) = (png_byte)((v >> 8) & 0xff); |
|
4123 *(sp + 3) = (png_byte)(v & 0xff); |
|
4124 |
|
4125 png_composite_16(v, b, a, png_ptr->background.blue); |
|
4126 *(sp + 4) = (png_byte)((v >> 8) & 0xff); |
|
4127 *(sp + 5) = (png_byte)(v & 0xff); |
|
4128 } |
|
4129 } |
|
4130 } |
|
4131 } |
|
4132 break; |
|
4133 } |
|
4134 |
|
4135 default: |
|
4136 break; |
|
4137 } |
|
4138 } |
|
4139 } |
|
4140 #endif |
|
4141 |
|
4142 #ifdef PNG_READ_GAMMA_SUPPORTED |
|
4143 /* Gamma correct the image, avoiding the alpha channel. Make sure |
|
4144 * you do this after you deal with the transparency issue on grayscale |
|
4145 * or RGB images. If your bit depth is 8, use gamma_table, if it |
|
4146 * is 16, use gamma_16_table and gamma_shift. Build these with |
|
4147 * build_gamma_table(). |
|
4148 */ |
|
4149 void /* PRIVATE */ |
|
4150 png_do_gamma(png_row_infop row_info, png_bytep row, png_structp png_ptr) |
|
4151 { |
|
4152 png_const_bytep gamma_table = png_ptr->gamma_table; |
|
4153 png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table; |
|
4154 int gamma_shift = png_ptr->gamma_shift; |
|
4155 |
|
4156 png_bytep sp; |
|
4157 png_uint_32 i; |
|
4158 png_uint_32 row_width=row_info->width; |
|
4159 |
|
4160 png_debug(1, "in png_do_gamma"); |
|
4161 |
|
4162 if (((row_info->bit_depth <= 8 && gamma_table != NULL) || |
|
4163 (row_info->bit_depth == 16 && gamma_16_table != NULL))) |
|
4164 { |
|
4165 switch (row_info->color_type) |
|
4166 { |
|
4167 case PNG_COLOR_TYPE_RGB: |
|
4168 { |
|
4169 if (row_info->bit_depth == 8) |
|
4170 { |
|
4171 sp = row; |
|
4172 for (i = 0; i < row_width; i++) |
|
4173 { |
|
4174 *sp = gamma_table[*sp]; |
|
4175 sp++; |
|
4176 *sp = gamma_table[*sp]; |
|
4177 sp++; |
|
4178 *sp = gamma_table[*sp]; |
|
4179 sp++; |
|
4180 } |
|
4181 } |
|
4182 |
|
4183 else /* if (row_info->bit_depth == 16) */ |
|
4184 { |
|
4185 sp = row; |
|
4186 for (i = 0; i < row_width; i++) |
|
4187 { |
|
4188 png_uint_16 v; |
|
4189 |
|
4190 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
4191 *sp = (png_byte)((v >> 8) & 0xff); |
|
4192 *(sp + 1) = (png_byte)(v & 0xff); |
|
4193 sp += 2; |
|
4194 |
|
4195 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
4196 *sp = (png_byte)((v >> 8) & 0xff); |
|
4197 *(sp + 1) = (png_byte)(v & 0xff); |
|
4198 sp += 2; |
|
4199 |
|
4200 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
4201 *sp = (png_byte)((v >> 8) & 0xff); |
|
4202 *(sp + 1) = (png_byte)(v & 0xff); |
|
4203 sp += 2; |
|
4204 } |
|
4205 } |
|
4206 break; |
|
4207 } |
|
4208 |
|
4209 case PNG_COLOR_TYPE_RGB_ALPHA: |
|
4210 { |
|
4211 if (row_info->bit_depth == 8) |
|
4212 { |
|
4213 sp = row; |
|
4214 for (i = 0; i < row_width; i++) |
|
4215 { |
|
4216 *sp = gamma_table[*sp]; |
|
4217 sp++; |
|
4218 |
|
4219 *sp = gamma_table[*sp]; |
|
4220 sp++; |
|
4221 |
|
4222 *sp = gamma_table[*sp]; |
|
4223 sp++; |
|
4224 |
|
4225 sp++; |
|
4226 } |
|
4227 } |
|
4228 |
|
4229 else /* if (row_info->bit_depth == 16) */ |
|
4230 { |
|
4231 sp = row; |
|
4232 for (i = 0; i < row_width; i++) |
|
4233 { |
|
4234 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
4235 *sp = (png_byte)((v >> 8) & 0xff); |
|
4236 *(sp + 1) = (png_byte)(v & 0xff); |
|
4237 sp += 2; |
|
4238 |
|
4239 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
4240 *sp = (png_byte)((v >> 8) & 0xff); |
|
4241 *(sp + 1) = (png_byte)(v & 0xff); |
|
4242 sp += 2; |
|
4243 |
|
4244 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
4245 *sp = (png_byte)((v >> 8) & 0xff); |
|
4246 *(sp + 1) = (png_byte)(v & 0xff); |
|
4247 sp += 4; |
|
4248 } |
|
4249 } |
|
4250 break; |
|
4251 } |
|
4252 |
|
4253 case PNG_COLOR_TYPE_GRAY_ALPHA: |
|
4254 { |
|
4255 if (row_info->bit_depth == 8) |
|
4256 { |
|
4257 sp = row; |
|
4258 for (i = 0; i < row_width; i++) |
|
4259 { |
|
4260 *sp = gamma_table[*sp]; |
|
4261 sp += 2; |
|
4262 } |
|
4263 } |
|
4264 |
|
4265 else /* if (row_info->bit_depth == 16) */ |
|
4266 { |
|
4267 sp = row; |
|
4268 for (i = 0; i < row_width; i++) |
|
4269 { |
|
4270 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
4271 *sp = (png_byte)((v >> 8) & 0xff); |
|
4272 *(sp + 1) = (png_byte)(v & 0xff); |
|
4273 sp += 4; |
|
4274 } |
|
4275 } |
|
4276 break; |
|
4277 } |
|
4278 |
|
4279 case PNG_COLOR_TYPE_GRAY: |
|
4280 { |
|
4281 if (row_info->bit_depth == 2) |
|
4282 { |
|
4283 sp = row; |
|
4284 for (i = 0; i < row_width; i += 4) |
|
4285 { |
|
4286 int a = *sp & 0xc0; |
|
4287 int b = *sp & 0x30; |
|
4288 int c = *sp & 0x0c; |
|
4289 int d = *sp & 0x03; |
|
4290 |
|
4291 *sp = (png_byte)( |
|
4292 ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)| |
|
4293 ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)| |
|
4294 ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)| |
|
4295 ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) )); |
|
4296 sp++; |
|
4297 } |
|
4298 } |
|
4299 |
|
4300 if (row_info->bit_depth == 4) |
|
4301 { |
|
4302 sp = row; |
|
4303 for (i = 0; i < row_width; i += 2) |
|
4304 { |
|
4305 int msb = *sp & 0xf0; |
|
4306 int lsb = *sp & 0x0f; |
|
4307 |
|
4308 *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0) |
|
4309 | (((int)gamma_table[(lsb << 4) | lsb]) >> 4)); |
|
4310 sp++; |
|
4311 } |
|
4312 } |
|
4313 |
|
4314 else if (row_info->bit_depth == 8) |
|
4315 { |
|
4316 sp = row; |
|
4317 for (i = 0; i < row_width; i++) |
|
4318 { |
|
4319 *sp = gamma_table[*sp]; |
|
4320 sp++; |
|
4321 } |
|
4322 } |
|
4323 |
|
4324 else if (row_info->bit_depth == 16) |
|
4325 { |
|
4326 sp = row; |
|
4327 for (i = 0; i < row_width; i++) |
|
4328 { |
|
4329 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
4330 *sp = (png_byte)((v >> 8) & 0xff); |
|
4331 *(sp + 1) = (png_byte)(v & 0xff); |
|
4332 sp += 2; |
|
4333 } |
|
4334 } |
|
4335 break; |
|
4336 } |
|
4337 |
|
4338 default: |
|
4339 break; |
|
4340 } |
|
4341 } |
|
4342 } |
|
4343 #endif |
|
4344 |
|
4345 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
4346 /* Encode the alpha channel to the output gamma (the input channel is always |
|
4347 * linear.) Called only with color types that have an alpha channel. Needs the |
|
4348 * from_1 tables. |
|
4349 */ |
|
4350 void /* PRIVATE */ |
|
4351 png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structp png_ptr) |
|
4352 { |
|
4353 png_uint_32 row_width = row_info->width; |
|
4354 |
|
4355 png_debug(1, "in png_do_encode_alpha"); |
|
4356 |
|
4357 if (row_info->color_type & PNG_COLOR_MASK_ALPHA) |
|
4358 { |
|
4359 if (row_info->bit_depth == 8) |
|
4360 { |
|
4361 PNG_CONST png_bytep table = png_ptr->gamma_from_1; |
|
4362 |
|
4363 if (table != NULL) |
|
4364 { |
|
4365 PNG_CONST int step = |
|
4366 (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2; |
|
4367 |
|
4368 /* The alpha channel is the last component: */ |
|
4369 row += step - 1; |
|
4370 |
|
4371 for (; row_width > 0; --row_width, row += step) |
|
4372 *row = table[*row]; |
|
4373 |
|
4374 return; |
|
4375 } |
|
4376 } |
|
4377 |
|
4378 else if (row_info->bit_depth == 16) |
|
4379 { |
|
4380 PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1; |
|
4381 PNG_CONST int gamma_shift = png_ptr->gamma_shift; |
|
4382 |
|
4383 if (table != NULL) |
|
4384 { |
|
4385 PNG_CONST int step = |
|
4386 (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4; |
|
4387 |
|
4388 /* The alpha channel is the last component: */ |
|
4389 row += step - 2; |
|
4390 |
|
4391 for (; row_width > 0; --row_width, row += step) |
|
4392 { |
|
4393 png_uint_16 v; |
|
4394 |
|
4395 v = table[*(row + 1) >> gamma_shift][*row]; |
|
4396 *row = (png_byte)((v >> 8) & 0xff); |
|
4397 *(row + 1) = (png_byte)(v & 0xff); |
|
4398 } |
|
4399 |
|
4400 return; |
|
4401 } |
|
4402 } |
|
4403 } |
|
4404 |
|
4405 /* Only get to here if called with a weird row_info; no harm has been done, |
|
4406 * so just issue a warning. |
|
4407 */ |
|
4408 png_warning(png_ptr, "png_do_encode_alpha: unexpected call"); |
|
4409 } |
|
4410 #endif |
|
4411 |
|
4412 #ifdef PNG_READ_EXPAND_SUPPORTED |
|
4413 /* Expands a palette row to an RGB or RGBA row depending |
|
4414 * upon whether you supply trans and num_trans. |
|
4415 */ |
|
4416 void /* PRIVATE */ |
|
4417 png_do_expand_palette(png_row_infop row_info, png_bytep row, |
|
4418 png_const_colorp palette, png_const_bytep trans_alpha, int num_trans) |
|
4419 { |
|
4420 int shift, value; |
|
4421 png_bytep sp, dp; |
|
4422 png_uint_32 i; |
|
4423 png_uint_32 row_width=row_info->width; |
|
4424 |
|
4425 png_debug(1, "in png_do_expand_palette"); |
|
4426 |
|
4427 if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) |
|
4428 { |
|
4429 if (row_info->bit_depth < 8) |
|
4430 { |
|
4431 switch (row_info->bit_depth) |
|
4432 { |
|
4433 case 1: |
|
4434 { |
|
4435 sp = row + (png_size_t)((row_width - 1) >> 3); |
|
4436 dp = row + (png_size_t)row_width - 1; |
|
4437 shift = 7 - (int)((row_width + 7) & 0x07); |
|
4438 for (i = 0; i < row_width; i++) |
|
4439 { |
|
4440 if ((*sp >> shift) & 0x01) |
|
4441 *dp = 1; |
|
4442 |
|
4443 else |
|
4444 *dp = 0; |
|
4445 |
|
4446 if (shift == 7) |
|
4447 { |
|
4448 shift = 0; |
|
4449 sp--; |
|
4450 } |
|
4451 |
|
4452 else |
|
4453 shift++; |
|
4454 |
|
4455 dp--; |
|
4456 } |
|
4457 break; |
|
4458 } |
|
4459 |
|
4460 case 2: |
|
4461 { |
|
4462 sp = row + (png_size_t)((row_width - 1) >> 2); |
|
4463 dp = row + (png_size_t)row_width - 1; |
|
4464 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
|
4465 for (i = 0; i < row_width; i++) |
|
4466 { |
|
4467 value = (*sp >> shift) & 0x03; |
|
4468 *dp = (png_byte)value; |
|
4469 if (shift == 6) |
|
4470 { |
|
4471 shift = 0; |
|
4472 sp--; |
|
4473 } |
|
4474 |
|
4475 else |
|
4476 shift += 2; |
|
4477 |
|
4478 dp--; |
|
4479 } |
|
4480 break; |
|
4481 } |
|
4482 |
|
4483 case 4: |
|
4484 { |
|
4485 sp = row + (png_size_t)((row_width - 1) >> 1); |
|
4486 dp = row + (png_size_t)row_width - 1; |
|
4487 shift = (int)((row_width & 0x01) << 2); |
|
4488 for (i = 0; i < row_width; i++) |
|
4489 { |
|
4490 value = (*sp >> shift) & 0x0f; |
|
4491 *dp = (png_byte)value; |
|
4492 if (shift == 4) |
|
4493 { |
|
4494 shift = 0; |
|
4495 sp--; |
|
4496 } |
|
4497 |
|
4498 else |
|
4499 shift += 4; |
|
4500 |
|
4501 dp--; |
|
4502 } |
|
4503 break; |
|
4504 } |
|
4505 |
|
4506 default: |
|
4507 break; |
|
4508 } |
|
4509 row_info->bit_depth = 8; |
|
4510 row_info->pixel_depth = 8; |
|
4511 row_info->rowbytes = row_width; |
|
4512 } |
|
4513 |
|
4514 if (row_info->bit_depth == 8) |
|
4515 { |
|
4516 { |
|
4517 if (num_trans > 0) |
|
4518 { |
|
4519 sp = row + (png_size_t)row_width - 1; |
|
4520 dp = row + (png_size_t)(row_width << 2) - 1; |
|
4521 |
|
4522 for (i = 0; i < row_width; i++) |
|
4523 { |
|
4524 if ((int)(*sp) >= num_trans) |
|
4525 *dp-- = 0xff; |
|
4526 |
|
4527 else |
|
4528 *dp-- = trans_alpha[*sp]; |
|
4529 |
|
4530 *dp-- = palette[*sp].blue; |
|
4531 *dp-- = palette[*sp].green; |
|
4532 *dp-- = palette[*sp].red; |
|
4533 sp--; |
|
4534 } |
|
4535 row_info->bit_depth = 8; |
|
4536 row_info->pixel_depth = 32; |
|
4537 row_info->rowbytes = row_width * 4; |
|
4538 row_info->color_type = 6; |
|
4539 row_info->channels = 4; |
|
4540 } |
|
4541 |
|
4542 else |
|
4543 { |
|
4544 sp = row + (png_size_t)row_width - 1; |
|
4545 dp = row + (png_size_t)(row_width * 3) - 1; |
|
4546 |
|
4547 for (i = 0; i < row_width; i++) |
|
4548 { |
|
4549 *dp-- = palette[*sp].blue; |
|
4550 *dp-- = palette[*sp].green; |
|
4551 *dp-- = palette[*sp].red; |
|
4552 sp--; |
|
4553 } |
|
4554 |
|
4555 row_info->bit_depth = 8; |
|
4556 row_info->pixel_depth = 24; |
|
4557 row_info->rowbytes = row_width * 3; |
|
4558 row_info->color_type = 2; |
|
4559 row_info->channels = 3; |
|
4560 } |
|
4561 } |
|
4562 } |
|
4563 } |
|
4564 } |
|
4565 |
|
4566 /* If the bit depth < 8, it is expanded to 8. Also, if the already |
|
4567 * expanded transparency value is supplied, an alpha channel is built. |
|
4568 */ |
|
4569 void /* PRIVATE */ |
|
4570 png_do_expand(png_row_infop row_info, png_bytep row, |
|
4571 png_const_color_16p trans_color) |
|
4572 { |
|
4573 int shift, value; |
|
4574 png_bytep sp, dp; |
|
4575 png_uint_32 i; |
|
4576 png_uint_32 row_width=row_info->width; |
|
4577 |
|
4578 png_debug(1, "in png_do_expand"); |
|
4579 |
|
4580 { |
|
4581 if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
|
4582 { |
|
4583 png_uint_16 gray = (png_uint_16)(trans_color ? trans_color->gray : 0); |
|
4584 |
|
4585 if (row_info->bit_depth < 8) |
|
4586 { |
|
4587 switch (row_info->bit_depth) |
|
4588 { |
|
4589 case 1: |
|
4590 { |
|
4591 gray = (png_uint_16)((gray & 0x01) * 0xff); |
|
4592 sp = row + (png_size_t)((row_width - 1) >> 3); |
|
4593 dp = row + (png_size_t)row_width - 1; |
|
4594 shift = 7 - (int)((row_width + 7) & 0x07); |
|
4595 for (i = 0; i < row_width; i++) |
|
4596 { |
|
4597 if ((*sp >> shift) & 0x01) |
|
4598 *dp = 0xff; |
|
4599 |
|
4600 else |
|
4601 *dp = 0; |
|
4602 |
|
4603 if (shift == 7) |
|
4604 { |
|
4605 shift = 0; |
|
4606 sp--; |
|
4607 } |
|
4608 |
|
4609 else |
|
4610 shift++; |
|
4611 |
|
4612 dp--; |
|
4613 } |
|
4614 break; |
|
4615 } |
|
4616 |
|
4617 case 2: |
|
4618 { |
|
4619 gray = (png_uint_16)((gray & 0x03) * 0x55); |
|
4620 sp = row + (png_size_t)((row_width - 1) >> 2); |
|
4621 dp = row + (png_size_t)row_width - 1; |
|
4622 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
|
4623 for (i = 0; i < row_width; i++) |
|
4624 { |
|
4625 value = (*sp >> shift) & 0x03; |
|
4626 *dp = (png_byte)(value | (value << 2) | (value << 4) | |
|
4627 (value << 6)); |
|
4628 if (shift == 6) |
|
4629 { |
|
4630 shift = 0; |
|
4631 sp--; |
|
4632 } |
|
4633 |
|
4634 else |
|
4635 shift += 2; |
|
4636 |
|
4637 dp--; |
|
4638 } |
|
4639 break; |
|
4640 } |
|
4641 |
|
4642 case 4: |
|
4643 { |
|
4644 gray = (png_uint_16)((gray & 0x0f) * 0x11); |
|
4645 sp = row + (png_size_t)((row_width - 1) >> 1); |
|
4646 dp = row + (png_size_t)row_width - 1; |
|
4647 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); |
|
4648 for (i = 0; i < row_width; i++) |
|
4649 { |
|
4650 value = (*sp >> shift) & 0x0f; |
|
4651 *dp = (png_byte)(value | (value << 4)); |
|
4652 if (shift == 4) |
|
4653 { |
|
4654 shift = 0; |
|
4655 sp--; |
|
4656 } |
|
4657 |
|
4658 else |
|
4659 shift = 4; |
|
4660 |
|
4661 dp--; |
|
4662 } |
|
4663 break; |
|
4664 } |
|
4665 |
|
4666 default: |
|
4667 break; |
|
4668 } |
|
4669 |
|
4670 row_info->bit_depth = 8; |
|
4671 row_info->pixel_depth = 8; |
|
4672 row_info->rowbytes = row_width; |
|
4673 } |
|
4674 |
|
4675 if (trans_color != NULL) |
|
4676 { |
|
4677 if (row_info->bit_depth == 8) |
|
4678 { |
|
4679 gray = gray & 0xff; |
|
4680 sp = row + (png_size_t)row_width - 1; |
|
4681 dp = row + (png_size_t)(row_width << 1) - 1; |
|
4682 |
|
4683 for (i = 0; i < row_width; i++) |
|
4684 { |
|
4685 if (*sp == gray) |
|
4686 *dp-- = 0; |
|
4687 |
|
4688 else |
|
4689 *dp-- = 0xff; |
|
4690 |
|
4691 *dp-- = *sp--; |
|
4692 } |
|
4693 } |
|
4694 |
|
4695 else if (row_info->bit_depth == 16) |
|
4696 { |
|
4697 png_byte gray_high = (png_byte)((gray >> 8) & 0xff); |
|
4698 png_byte gray_low = (png_byte)(gray & 0xff); |
|
4699 sp = row + row_info->rowbytes - 1; |
|
4700 dp = row + (row_info->rowbytes << 1) - 1; |
|
4701 for (i = 0; i < row_width; i++) |
|
4702 { |
|
4703 if (*(sp - 1) == gray_high && *(sp) == gray_low) |
|
4704 { |
|
4705 *dp-- = 0; |
|
4706 *dp-- = 0; |
|
4707 } |
|
4708 |
|
4709 else |
|
4710 { |
|
4711 *dp-- = 0xff; |
|
4712 *dp-- = 0xff; |
|
4713 } |
|
4714 |
|
4715 *dp-- = *sp--; |
|
4716 *dp-- = *sp--; |
|
4717 } |
|
4718 } |
|
4719 |
|
4720 row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; |
|
4721 row_info->channels = 2; |
|
4722 row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); |
|
4723 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, |
|
4724 row_width); |
|
4725 } |
|
4726 } |
|
4727 else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_color) |
|
4728 { |
|
4729 if (row_info->bit_depth == 8) |
|
4730 { |
|
4731 png_byte red = (png_byte)(trans_color->red & 0xff); |
|
4732 png_byte green = (png_byte)(trans_color->green & 0xff); |
|
4733 png_byte blue = (png_byte)(trans_color->blue & 0xff); |
|
4734 sp = row + (png_size_t)row_info->rowbytes - 1; |
|
4735 dp = row + (png_size_t)(row_width << 2) - 1; |
|
4736 for (i = 0; i < row_width; i++) |
|
4737 { |
|
4738 if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue) |
|
4739 *dp-- = 0; |
|
4740 |
|
4741 else |
|
4742 *dp-- = 0xff; |
|
4743 |
|
4744 *dp-- = *sp--; |
|
4745 *dp-- = *sp--; |
|
4746 *dp-- = *sp--; |
|
4747 } |
|
4748 } |
|
4749 else if (row_info->bit_depth == 16) |
|
4750 { |
|
4751 png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff); |
|
4752 png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff); |
|
4753 png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff); |
|
4754 png_byte red_low = (png_byte)(trans_color->red & 0xff); |
|
4755 png_byte green_low = (png_byte)(trans_color->green & 0xff); |
|
4756 png_byte blue_low = (png_byte)(trans_color->blue & 0xff); |
|
4757 sp = row + row_info->rowbytes - 1; |
|
4758 dp = row + (png_size_t)(row_width << 3) - 1; |
|
4759 for (i = 0; i < row_width; i++) |
|
4760 { |
|
4761 if (*(sp - 5) == red_high && |
|
4762 *(sp - 4) == red_low && |
|
4763 *(sp - 3) == green_high && |
|
4764 *(sp - 2) == green_low && |
|
4765 *(sp - 1) == blue_high && |
|
4766 *(sp ) == blue_low) |
|
4767 { |
|
4768 *dp-- = 0; |
|
4769 *dp-- = 0; |
|
4770 } |
|
4771 |
|
4772 else |
|
4773 { |
|
4774 *dp-- = 0xff; |
|
4775 *dp-- = 0xff; |
|
4776 } |
|
4777 |
|
4778 *dp-- = *sp--; |
|
4779 *dp-- = *sp--; |
|
4780 *dp-- = *sp--; |
|
4781 *dp-- = *sp--; |
|
4782 *dp-- = *sp--; |
|
4783 *dp-- = *sp--; |
|
4784 } |
|
4785 } |
|
4786 row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
|
4787 row_info->channels = 4; |
|
4788 row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); |
|
4789 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
4790 } |
|
4791 } |
|
4792 } |
|
4793 #endif |
|
4794 |
|
4795 #ifdef PNG_READ_EXPAND_16_SUPPORTED |
|
4796 /* If the bit depth is 8 and the colour type is not a palette type expand the |
|
4797 * whole row to 16 bits. Has no effect otherwise. |
|
4798 */ |
|
4799 void /* PRIVATE */ |
|
4800 png_do_expand_16(png_row_infop row_info, png_bytep row) |
|
4801 { |
|
4802 if (row_info->bit_depth == 8 && |
|
4803 row_info->color_type != PNG_COLOR_TYPE_PALETTE) |
|
4804 { |
|
4805 /* The row have a sequence of bytes containing [0..255] and we need |
|
4806 * to turn it into another row containing [0..65535], to do this we |
|
4807 * calculate: |
|
4808 * |
|
4809 * (input / 255) * 65535 |
|
4810 * |
|
4811 * Which happens to be exactly input * 257 and this can be achieved |
|
4812 * simply by byte replication in place (copying backwards). |
|
4813 */ |
|
4814 png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */ |
|
4815 png_byte *dp = sp + row_info->rowbytes; /* destination, end + 1 */ |
|
4816 while (dp > sp) |
|
4817 dp[-2] = dp[-1] = *--sp, dp -= 2; |
|
4818 |
|
4819 row_info->rowbytes *= 2; |
|
4820 row_info->bit_depth = 16; |
|
4821 row_info->pixel_depth = (png_byte)(row_info->channels * 16); |
|
4822 } |
|
4823 } |
|
4824 #endif |
|
4825 |
|
4826 #ifdef PNG_READ_QUANTIZE_SUPPORTED |
|
4827 void /* PRIVATE */ |
|
4828 png_do_quantize(png_row_infop row_info, png_bytep row, |
|
4829 png_const_bytep palette_lookup, png_const_bytep quantize_lookup) |
|
4830 { |
|
4831 png_bytep sp, dp; |
|
4832 png_uint_32 i; |
|
4833 png_uint_32 row_width=row_info->width; |
|
4834 |
|
4835 png_debug(1, "in png_do_quantize"); |
|
4836 |
|
4837 if (row_info->bit_depth == 8) |
|
4838 { |
|
4839 if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup) |
|
4840 { |
|
4841 int r, g, b, p; |
|
4842 sp = row; |
|
4843 dp = row; |
|
4844 for (i = 0; i < row_width; i++) |
|
4845 { |
|
4846 r = *sp++; |
|
4847 g = *sp++; |
|
4848 b = *sp++; |
|
4849 |
|
4850 /* This looks real messy, but the compiler will reduce |
|
4851 * it down to a reasonable formula. For example, with |
|
4852 * 5 bits per color, we get: |
|
4853 * p = (((r >> 3) & 0x1f) << 10) | |
|
4854 * (((g >> 3) & 0x1f) << 5) | |
|
4855 * ((b >> 3) & 0x1f); |
|
4856 */ |
|
4857 p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & |
|
4858 ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << |
|
4859 (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | |
|
4860 (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & |
|
4861 ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << |
|
4862 (PNG_QUANTIZE_BLUE_BITS)) | |
|
4863 ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & |
|
4864 ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); |
|
4865 |
|
4866 *dp++ = palette_lookup[p]; |
|
4867 } |
|
4868 |
|
4869 row_info->color_type = PNG_COLOR_TYPE_PALETTE; |
|
4870 row_info->channels = 1; |
|
4871 row_info->pixel_depth = row_info->bit_depth; |
|
4872 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
4873 } |
|
4874 |
|
4875 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && |
|
4876 palette_lookup != NULL) |
|
4877 { |
|
4878 int r, g, b, p; |
|
4879 sp = row; |
|
4880 dp = row; |
|
4881 for (i = 0; i < row_width; i++) |
|
4882 { |
|
4883 r = *sp++; |
|
4884 g = *sp++; |
|
4885 b = *sp++; |
|
4886 sp++; |
|
4887 |
|
4888 p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & |
|
4889 ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << |
|
4890 (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | |
|
4891 (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & |
|
4892 ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << |
|
4893 (PNG_QUANTIZE_BLUE_BITS)) | |
|
4894 ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & |
|
4895 ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); |
|
4896 |
|
4897 *dp++ = palette_lookup[p]; |
|
4898 } |
|
4899 |
|
4900 row_info->color_type = PNG_COLOR_TYPE_PALETTE; |
|
4901 row_info->channels = 1; |
|
4902 row_info->pixel_depth = row_info->bit_depth; |
|
4903 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
4904 } |
|
4905 |
|
4906 else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && |
|
4907 quantize_lookup) |
|
4908 { |
|
4909 sp = row; |
|
4910 |
|
4911 for (i = 0; i < row_width; i++, sp++) |
|
4912 { |
|
4913 *sp = quantize_lookup[*sp]; |
|
4914 } |
|
4915 } |
|
4916 } |
|
4917 } |
|
4918 #endif /* PNG_READ_QUANTIZE_SUPPORTED */ |
|
4919 #endif /* PNG_READ_TRANSFORMS_SUPPORTED */ |
|
4920 |
|
4921 #ifdef PNG_MNG_FEATURES_SUPPORTED |
|
4922 /* Undoes intrapixel differencing */ |
|
4923 void /* PRIVATE */ |
|
4924 png_do_read_intrapixel(png_row_infop row_info, png_bytep row) |
|
4925 { |
|
4926 png_debug(1, "in png_do_read_intrapixel"); |
|
4927 |
|
4928 if ( |
|
4929 (row_info->color_type & PNG_COLOR_MASK_COLOR)) |
|
4930 { |
|
4931 int bytes_per_pixel; |
|
4932 png_uint_32 row_width = row_info->width; |
|
4933 |
|
4934 if (row_info->bit_depth == 8) |
|
4935 { |
|
4936 png_bytep rp; |
|
4937 png_uint_32 i; |
|
4938 |
|
4939 if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
|
4940 bytes_per_pixel = 3; |
|
4941 |
|
4942 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
4943 bytes_per_pixel = 4; |
|
4944 |
|
4945 else |
|
4946 return; |
|
4947 |
|
4948 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) |
|
4949 { |
|
4950 *(rp) = (png_byte)((256 + *rp + *(rp + 1)) & 0xff); |
|
4951 *(rp+2) = (png_byte)((256 + *(rp + 2) + *(rp + 1)) & 0xff); |
|
4952 } |
|
4953 } |
|
4954 else if (row_info->bit_depth == 16) |
|
4955 { |
|
4956 png_bytep rp; |
|
4957 png_uint_32 i; |
|
4958 |
|
4959 if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
|
4960 bytes_per_pixel = 6; |
|
4961 |
|
4962 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
4963 bytes_per_pixel = 8; |
|
4964 |
|
4965 else |
|
4966 return; |
|
4967 |
|
4968 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) |
|
4969 { |
|
4970 png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); |
|
4971 png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); |
|
4972 png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); |
|
4973 png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL); |
|
4974 png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL); |
|
4975 *(rp ) = (png_byte)((red >> 8) & 0xff); |
|
4976 *(rp + 1) = (png_byte)(red & 0xff); |
|
4977 *(rp + 4) = (png_byte)((blue >> 8) & 0xff); |
|
4978 *(rp + 5) = (png_byte)(blue & 0xff); |
|
4979 } |
|
4980 } |
|
4981 } |
|
4982 } |
|
4983 #endif /* PNG_MNG_FEATURES_SUPPORTED */ |
|
4984 #endif /* PNG_READ_SUPPORTED */ |