6788458: PNGImageReader ignores tRNS chunk while reading non-indexed RGB/Gray images
Reviewed-by: prr, pnarayanan, kaddepalli
/*
* Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.sun.imageio.plugins.png;
import java.awt.image.ColorModel;
import java.awt.image.IndexColorModel;
import java.awt.image.SampleModel;
import java.util.ArrayList;
import java.util.StringTokenizer;
import java.util.ListIterator;
import java.time.LocalDateTime;
import java.time.OffsetDateTime;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;
import java.time.temporal.TemporalAccessor;
import javax.imageio.ImageTypeSpecifier;
import javax.imageio.metadata.IIOInvalidTreeException;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.metadata.IIOMetadataFormatImpl;
import javax.imageio.metadata.IIOMetadataNode;
import org.w3c.dom.Node;
public class PNGMetadata extends IIOMetadata implements Cloneable {
// package scope
public static final String
nativeMetadataFormatName = "javax_imageio_png_1.0";
protected static final String nativeMetadataFormatClassName
= "com.sun.imageio.plugins.png.PNGMetadataFormat";
// Color types for IHDR chunk
static final String[] IHDR_colorTypeNames = {
"Grayscale", null, "RGB", "Palette",
"GrayAlpha", null, "RGBAlpha"
};
static final int[] IHDR_numChannels = {
1, 0, 3, 3, 2, 0, 4
};
// Bit depths for IHDR chunk
static final String[] IHDR_bitDepths = {
"1", "2", "4", "8", "16"
};
// Compression methods for IHDR chunk
static final String[] IHDR_compressionMethodNames = {
"deflate"
};
// Filter methods for IHDR chunk
static final String[] IHDR_filterMethodNames = {
"adaptive"
};
// Interlace methods for IHDR chunk
static final String[] IHDR_interlaceMethodNames = {
"none", "adam7"
};
// Compression methods for iCCP chunk
static final String[] iCCP_compressionMethodNames = {
"deflate"
};
// Compression methods for zTXt chunk
static final String[] zTXt_compressionMethodNames = {
"deflate"
};
// "Unknown" unit for pHYs chunk
public static final int PHYS_UNIT_UNKNOWN = 0;
// "Meter" unit for pHYs chunk
public static final int PHYS_UNIT_METER = 1;
// Unit specifiers for pHYs chunk
static final String[] unitSpecifierNames = {
"unknown", "meter"
};
// Rendering intents for sRGB chunk
static final String[] renderingIntentNames = {
"Perceptual", // 0
"Relative colorimetric", // 1
"Saturation", // 2
"Absolute colorimetric" // 3
};
// Color space types for Chroma->ColorSpaceType node
static final String[] colorSpaceTypeNames = {
"GRAY", null, "RGB", "RGB",
"GRAY", null, "RGB"
};
// IHDR chunk
public boolean IHDR_present;
public int IHDR_width;
public int IHDR_height;
public int IHDR_bitDepth;
public int IHDR_colorType;
public int IHDR_compressionMethod;
public int IHDR_filterMethod;
public int IHDR_interlaceMethod; // 0 == none, 1 == adam7
// PLTE chunk
public boolean PLTE_present;
public byte[] PLTE_red;
public byte[] PLTE_green;
public byte[] PLTE_blue;
// If non-null, used to reorder palette entries during encoding in
// order to minimize the size of the tRNS chunk. Thus an index of
// 'i' in the source should be encoded as index 'PLTE_order[i]'.
// PLTE_order will be null unless 'initialize' is called with an
// IndexColorModel image type.
public int[] PLTE_order = null;
// bKGD chunk
// If external (non-PNG sourced) data has red = green = blue,
// always store it as gray and promote when writing
public boolean bKGD_present;
public int bKGD_colorType; // PNG_COLOR_GRAY, _RGB, or _PALETTE
public int bKGD_index;
public int bKGD_gray;
public int bKGD_red;
public int bKGD_green;
public int bKGD_blue;
// cHRM chunk
public boolean cHRM_present;
public int cHRM_whitePointX;
public int cHRM_whitePointY;
public int cHRM_redX;
public int cHRM_redY;
public int cHRM_greenX;
public int cHRM_greenY;
public int cHRM_blueX;
public int cHRM_blueY;
// gAMA chunk
public boolean gAMA_present;
public int gAMA_gamma;
// hIST chunk
public boolean hIST_present;
public char[] hIST_histogram;
// iCCP chunk
public boolean iCCP_present;
public String iCCP_profileName;
public int iCCP_compressionMethod;
public byte[] iCCP_compressedProfile;
// iTXt chunk
public ArrayList<String> iTXt_keyword = new ArrayList<String>();
public ArrayList<Boolean> iTXt_compressionFlag = new ArrayList<Boolean>();
public ArrayList<Integer> iTXt_compressionMethod = new ArrayList<Integer>();
public ArrayList<String> iTXt_languageTag = new ArrayList<String>();
public ArrayList<String> iTXt_translatedKeyword = new ArrayList<String>();
public ArrayList<String> iTXt_text = new ArrayList<String>();
// pHYs chunk
public boolean pHYs_present;
public int pHYs_pixelsPerUnitXAxis;
public int pHYs_pixelsPerUnitYAxis;
public int pHYs_unitSpecifier; // 0 == unknown, 1 == meter
// sBIT chunk
public boolean sBIT_present;
public int sBIT_colorType; // PNG_COLOR_GRAY, _GRAY_ALPHA, _RGB, _RGB_ALPHA
public int sBIT_grayBits;
public int sBIT_redBits;
public int sBIT_greenBits;
public int sBIT_blueBits;
public int sBIT_alphaBits;
// sPLT chunk
public boolean sPLT_present;
public String sPLT_paletteName; // 1-79 characters
public int sPLT_sampleDepth; // 8 or 16
public int[] sPLT_red;
public int[] sPLT_green;
public int[] sPLT_blue;
public int[] sPLT_alpha;
public int[] sPLT_frequency;
// sRGB chunk
public boolean sRGB_present;
public int sRGB_renderingIntent;
// tEXt chunk
public ArrayList<String> tEXt_keyword = new ArrayList<String>(); // 1-79 characters
public ArrayList<String> tEXt_text = new ArrayList<String>();
// tIME chunk. Gives the image modification time.
public boolean tIME_present;
public int tIME_year;
public int tIME_month;
public int tIME_day;
public int tIME_hour;
public int tIME_minute;
public int tIME_second;
// Specifies whether metadata contains Standard/Document/ImageCreationTime
public boolean creation_time_present;
// Values that make up Standard/Document/ImageCreationTime
public int creation_time_year;
public int creation_time_month;
public int creation_time_day;
public int creation_time_hour;
public int creation_time_minute;
public int creation_time_second;
public ZoneOffset creation_time_offset;
/*
* tEXt_creation_time_present- Specifies whether any text chunk (tEXt, iTXt,
* zTXt) exists with image creation time. The data structure corresponding
* to the last decoded text chunk with creation time is indicated by the
* iterator- tEXt_creation_time_iter.
*
* Any update to the text chunks with creation time is reflected on
* Standard/Document/ImageCreationTime after retrieving time from the text
* chunk. If there are multiple text chunks with creation time, the time
* retrieved from the last decoded text chunk will be used. A point to note
* is that, retrieval of time from text chunks is possible only if the
* encoded time in the chunk confirms to either the recommended RFC1123
* format or ISO format.
*
* Similarly, any update to Standard/Document/ImageCreationTime is reflected
* on the last decoded text chunk's data structure with time encoded in
* RFC1123 format. By updating the text chunk's data structure, we also
* ensure that PNGImageWriter will write image creation time on the output.
*/
public boolean tEXt_creation_time_present;
private ListIterator<String> tEXt_creation_time_iter = null;
public static final String tEXt_creationTimeKey = "Creation Time";
// tRNS chunk
// If external (non-PNG sourced) data has red = green = blue,
// always store it as gray and promote when writing
public boolean tRNS_present;
public int tRNS_colorType; // PNG_COLOR_GRAY, _RGB, or _PALETTE
public byte[] tRNS_alpha; // May have fewer entries than PLTE_red, etc.
public int tRNS_gray;
public int tRNS_red;
public int tRNS_green;
public int tRNS_blue;
// zTXt chunk
public ArrayList<String> zTXt_keyword = new ArrayList<String>();
public ArrayList<Integer> zTXt_compressionMethod = new ArrayList<Integer>();
public ArrayList<String> zTXt_text = new ArrayList<String>();
// Unknown chunks
public ArrayList<String> unknownChunkType = new ArrayList<String>();
public ArrayList<byte[]> unknownChunkData = new ArrayList<byte[]>();
public PNGMetadata() {
super(true,
nativeMetadataFormatName,
nativeMetadataFormatClassName,
null, null);
}
public PNGMetadata(IIOMetadata metadata) {
// TODO -- implement
}
/**
* Sets the IHDR_bitDepth and IHDR_colorType variables.
* The {@code numBands} parameter is necessary since
* we may only be writing a subset of the image bands.
*/
public void initialize(ImageTypeSpecifier imageType, int numBands) {
ColorModel colorModel = imageType.getColorModel();
SampleModel sampleModel = imageType.getSampleModel();
// Initialize IHDR_bitDepth
int[] sampleSize = sampleModel.getSampleSize();
int bitDepth = sampleSize[0];
// Choose max bit depth over all channels
// Fixes bug 4413109
for (int i = 1; i < sampleSize.length; i++) {
if (sampleSize[i] > bitDepth) {
bitDepth = sampleSize[i];
}
}
// Multi-channel images must have a bit depth of 8 or 16
if (sampleSize.length > 1 && bitDepth < 8) {
bitDepth = 8;
}
// Round bit depth up to a power of 2
if (bitDepth > 2 && bitDepth < 4) {
bitDepth = 4;
} else if (bitDepth > 4 && bitDepth < 8) {
bitDepth = 8;
} else if (bitDepth > 8 && bitDepth < 16) {
bitDepth = 16;
} else if (bitDepth > 16) {
throw new RuntimeException("bitDepth > 16!");
}
IHDR_bitDepth = bitDepth;
// Initialize IHDR_colorType
if (colorModel instanceof IndexColorModel) {
IndexColorModel icm = (IndexColorModel)colorModel;
int size = icm.getMapSize();
byte[] reds = new byte[size];
icm.getReds(reds);
byte[] greens = new byte[size];
icm.getGreens(greens);
byte[] blues = new byte[size];
icm.getBlues(blues);
// Determine whether the color tables are actually a gray ramp
// if the color type has not been set previously
boolean isGray = false;
if (!IHDR_present ||
(IHDR_colorType != PNGImageReader.PNG_COLOR_PALETTE)) {
isGray = true;
int scale = 255/((1 << IHDR_bitDepth) - 1);
for (int i = 0; i < size; i++) {
byte red = reds[i];
if ((red != (byte)(i*scale)) ||
(red != greens[i]) ||
(red != blues[i])) {
isGray = false;
break;
}
}
}
// Determine whether transparency exists
boolean hasAlpha = colorModel.hasAlpha();
byte[] alpha = null;
if (hasAlpha) {
alpha = new byte[size];
icm.getAlphas(alpha);
}
/*
* NB: PNG_COLOR_GRAY_ALPHA color type may be not optimal for images
* contained more than 1024 pixels (or even than 768 pixels in case of
* single transparent pixel in palette).
* For such images alpha samples in raster will occupy more space than
* it is required to store palette so it could be reasonable to
* use PNG_COLOR_PALETTE color type for large images.
*/
if (isGray && hasAlpha && (bitDepth == 8 || bitDepth == 16)) {
IHDR_colorType = PNGImageReader.PNG_COLOR_GRAY_ALPHA;
} else if (isGray && !hasAlpha) {
IHDR_colorType = PNGImageReader.PNG_COLOR_GRAY;
} else {
IHDR_colorType = PNGImageReader.PNG_COLOR_PALETTE;
PLTE_present = true;
PLTE_order = null;
PLTE_red = reds.clone();
PLTE_green = greens.clone();
PLTE_blue = blues.clone();
if (hasAlpha) {
tRNS_present = true;
tRNS_colorType = PNGImageReader.PNG_COLOR_PALETTE;
PLTE_order = new int[alpha.length];
// Reorder the palette so that non-opaque entries
// come first. Since the tRNS chunk does not have
// to store trailing 255's, this can save a
// considerable amount of space when encoding
// images with only one transparent pixel value,
// e.g., images from GIF sources.
byte[] newAlpha = new byte[alpha.length];
// Scan for non-opaque entries and assign them
// positions starting at 0.
int newIndex = 0;
for (int i = 0; i < alpha.length; i++) {
if (alpha[i] != (byte)255) {
PLTE_order[i] = newIndex;
newAlpha[newIndex] = alpha[i];
++newIndex;
}
}
int numTransparent = newIndex;
// Scan for opaque entries and assign them
// positions following the non-opaque entries.
for (int i = 0; i < alpha.length; i++) {
if (alpha[i] == (byte)255) {
PLTE_order[i] = newIndex++;
}
}
// Reorder the palettes
byte[] oldRed = PLTE_red;
byte[] oldGreen = PLTE_green;
byte[] oldBlue = PLTE_blue;
int len = oldRed.length; // All have the same length
PLTE_red = new byte[len];
PLTE_green = new byte[len];
PLTE_blue = new byte[len];
for (int i = 0; i < len; i++) {
PLTE_red[PLTE_order[i]] = oldRed[i];
PLTE_green[PLTE_order[i]] = oldGreen[i];
PLTE_blue[PLTE_order[i]] = oldBlue[i];
}
// Copy only the transparent entries into tRNS_alpha
tRNS_alpha = new byte[numTransparent];
System.arraycopy(newAlpha, 0,
tRNS_alpha, 0, numTransparent);
}
}
} else {
if (numBands == 1) {
IHDR_colorType = PNGImageReader.PNG_COLOR_GRAY;
} else if (numBands == 2) {
IHDR_colorType = PNGImageReader.PNG_COLOR_GRAY_ALPHA;
} else if (numBands == 3) {
IHDR_colorType = PNGImageReader.PNG_COLOR_RGB;
} else if (numBands == 4) {
IHDR_colorType = PNGImageReader.PNG_COLOR_RGB_ALPHA;
} else {
throw new RuntimeException("Number of bands not 1-4!");
}
}
IHDR_present = true;
}
public boolean isReadOnly() {
return false;
}
private ArrayList<byte[]> cloneBytesArrayList(ArrayList<byte[]> in) {
if (in == null) {
return null;
} else {
ArrayList<byte[]> list = new ArrayList<byte[]>(in.size());
for (byte[] b: in) {
list.add((b == null) ? null : b.clone());
}
return list;
}
}
// Deep clone
public Object clone() {
PNGMetadata metadata;
try {
metadata = (PNGMetadata)super.clone();
} catch (CloneNotSupportedException e) {
return null;
}
// unknownChunkData needs deep clone
metadata.unknownChunkData =
cloneBytesArrayList(this.unknownChunkData);
return metadata;
}
public Node getAsTree(String formatName) {
if (formatName.equals(nativeMetadataFormatName)) {
return getNativeTree();
} else if (formatName.equals
(IIOMetadataFormatImpl.standardMetadataFormatName)) {
return getStandardTree();
} else {
throw new IllegalArgumentException("Not a recognized format!");
}
}
private Node getNativeTree() {
IIOMetadataNode node = null; // scratch node
IIOMetadataNode root = new IIOMetadataNode(nativeMetadataFormatName);
// IHDR
if (IHDR_present) {
IIOMetadataNode IHDR_node = new IIOMetadataNode("IHDR");
IHDR_node.setAttribute("width", Integer.toString(IHDR_width));
IHDR_node.setAttribute("height", Integer.toString(IHDR_height));
IHDR_node.setAttribute("bitDepth",
Integer.toString(IHDR_bitDepth));
IHDR_node.setAttribute("colorType",
IHDR_colorTypeNames[IHDR_colorType]);
// IHDR_compressionMethod must be 0 in PNG 1.1
IHDR_node.setAttribute("compressionMethod",
IHDR_compressionMethodNames[IHDR_compressionMethod]);
// IHDR_filterMethod must be 0 in PNG 1.1
IHDR_node.setAttribute("filterMethod",
IHDR_filterMethodNames[IHDR_filterMethod]);
IHDR_node.setAttribute("interlaceMethod",
IHDR_interlaceMethodNames[IHDR_interlaceMethod]);
root.appendChild(IHDR_node);
}
// PLTE
if (PLTE_present) {
IIOMetadataNode PLTE_node = new IIOMetadataNode("PLTE");
int numEntries = PLTE_red.length;
for (int i = 0; i < numEntries; i++) {
IIOMetadataNode entry = new IIOMetadataNode("PLTEEntry");
entry.setAttribute("index", Integer.toString(i));
entry.setAttribute("red",
Integer.toString(PLTE_red[i] & 0xff));
entry.setAttribute("green",
Integer.toString(PLTE_green[i] & 0xff));
entry.setAttribute("blue",
Integer.toString(PLTE_blue[i] & 0xff));
PLTE_node.appendChild(entry);
}
root.appendChild(PLTE_node);
}
// bKGD
if (bKGD_present) {
IIOMetadataNode bKGD_node = new IIOMetadataNode("bKGD");
if (bKGD_colorType == PNGImageReader.PNG_COLOR_PALETTE) {
node = new IIOMetadataNode("bKGD_Palette");
node.setAttribute("index", Integer.toString(bKGD_index));
} else if (bKGD_colorType == PNGImageReader.PNG_COLOR_GRAY) {
node = new IIOMetadataNode("bKGD_Grayscale");
node.setAttribute("gray", Integer.toString(bKGD_gray));
} else if (bKGD_colorType == PNGImageReader.PNG_COLOR_RGB) {
node = new IIOMetadataNode("bKGD_RGB");
node.setAttribute("red", Integer.toString(bKGD_red));
node.setAttribute("green", Integer.toString(bKGD_green));
node.setAttribute("blue", Integer.toString(bKGD_blue));
}
bKGD_node.appendChild(node);
root.appendChild(bKGD_node);
}
// cHRM
if (cHRM_present) {
IIOMetadataNode cHRM_node = new IIOMetadataNode("cHRM");
cHRM_node.setAttribute("whitePointX",
Integer.toString(cHRM_whitePointX));
cHRM_node.setAttribute("whitePointY",
Integer.toString(cHRM_whitePointY));
cHRM_node.setAttribute("redX", Integer.toString(cHRM_redX));
cHRM_node.setAttribute("redY", Integer.toString(cHRM_redY));
cHRM_node.setAttribute("greenX", Integer.toString(cHRM_greenX));
cHRM_node.setAttribute("greenY", Integer.toString(cHRM_greenY));
cHRM_node.setAttribute("blueX", Integer.toString(cHRM_blueX));
cHRM_node.setAttribute("blueY", Integer.toString(cHRM_blueY));
root.appendChild(cHRM_node);
}
// gAMA
if (gAMA_present) {
IIOMetadataNode gAMA_node = new IIOMetadataNode("gAMA");
gAMA_node.setAttribute("value", Integer.toString(gAMA_gamma));
root.appendChild(gAMA_node);
}
// hIST
if (hIST_present) {
IIOMetadataNode hIST_node = new IIOMetadataNode("hIST");
for (int i = 0; i < hIST_histogram.length; i++) {
IIOMetadataNode hist =
new IIOMetadataNode("hISTEntry");
hist.setAttribute("index", Integer.toString(i));
hist.setAttribute("value",
Integer.toString(hIST_histogram[i]));
hIST_node.appendChild(hist);
}
root.appendChild(hIST_node);
}
// iCCP
if (iCCP_present) {
IIOMetadataNode iCCP_node = new IIOMetadataNode("iCCP");
iCCP_node.setAttribute("profileName", iCCP_profileName);
iCCP_node.setAttribute("compressionMethod",
iCCP_compressionMethodNames[iCCP_compressionMethod]);
Object profile = iCCP_compressedProfile;
if (profile != null) {
profile = ((byte[])profile).clone();
}
iCCP_node.setUserObject(profile);
root.appendChild(iCCP_node);
}
// iTXt
if (iTXt_keyword.size() > 0) {
IIOMetadataNode iTXt_parent = new IIOMetadataNode("iTXt");
for (int i = 0; i < iTXt_keyword.size(); i++) {
IIOMetadataNode iTXt_node = new IIOMetadataNode("iTXtEntry");
iTXt_node.setAttribute("keyword", iTXt_keyword.get(i));
iTXt_node.setAttribute("compressionFlag",
iTXt_compressionFlag.get(i) ? "TRUE" : "FALSE");
iTXt_node.setAttribute("compressionMethod",
iTXt_compressionMethod.get(i).toString());
iTXt_node.setAttribute("languageTag",
iTXt_languageTag.get(i));
iTXt_node.setAttribute("translatedKeyword",
iTXt_translatedKeyword.get(i));
iTXt_node.setAttribute("text", iTXt_text.get(i));
iTXt_parent.appendChild(iTXt_node);
}
root.appendChild(iTXt_parent);
}
// pHYs
if (pHYs_present) {
IIOMetadataNode pHYs_node = new IIOMetadataNode("pHYs");
pHYs_node.setAttribute("pixelsPerUnitXAxis",
Integer.toString(pHYs_pixelsPerUnitXAxis));
pHYs_node.setAttribute("pixelsPerUnitYAxis",
Integer.toString(pHYs_pixelsPerUnitYAxis));
pHYs_node.setAttribute("unitSpecifier",
unitSpecifierNames[pHYs_unitSpecifier]);
root.appendChild(pHYs_node);
}
// sBIT
if (sBIT_present) {
IIOMetadataNode sBIT_node = new IIOMetadataNode("sBIT");
if (sBIT_colorType == PNGImageReader.PNG_COLOR_GRAY) {
node = new IIOMetadataNode("sBIT_Grayscale");
node.setAttribute("gray",
Integer.toString(sBIT_grayBits));
} else if (sBIT_colorType == PNGImageReader.PNG_COLOR_GRAY_ALPHA) {
node = new IIOMetadataNode("sBIT_GrayAlpha");
node.setAttribute("gray",
Integer.toString(sBIT_grayBits));
node.setAttribute("alpha",
Integer.toString(sBIT_alphaBits));
} else if (sBIT_colorType == PNGImageReader.PNG_COLOR_RGB) {
node = new IIOMetadataNode("sBIT_RGB");
node.setAttribute("red",
Integer.toString(sBIT_redBits));
node.setAttribute("green",
Integer.toString(sBIT_greenBits));
node.setAttribute("blue",
Integer.toString(sBIT_blueBits));
} else if (sBIT_colorType == PNGImageReader.PNG_COLOR_RGB_ALPHA) {
node = new IIOMetadataNode("sBIT_RGBAlpha");
node.setAttribute("red",
Integer.toString(sBIT_redBits));
node.setAttribute("green",
Integer.toString(sBIT_greenBits));
node.setAttribute("blue",
Integer.toString(sBIT_blueBits));
node.setAttribute("alpha",
Integer.toString(sBIT_alphaBits));
} else if (sBIT_colorType == PNGImageReader.PNG_COLOR_PALETTE) {
node = new IIOMetadataNode("sBIT_Palette");
node.setAttribute("red",
Integer.toString(sBIT_redBits));
node.setAttribute("green",
Integer.toString(sBIT_greenBits));
node.setAttribute("blue",
Integer.toString(sBIT_blueBits));
}
sBIT_node.appendChild(node);
root.appendChild(sBIT_node);
}
// sPLT
if (sPLT_present) {
IIOMetadataNode sPLT_node = new IIOMetadataNode("sPLT");
sPLT_node.setAttribute("name", sPLT_paletteName);
sPLT_node.setAttribute("sampleDepth",
Integer.toString(sPLT_sampleDepth));
int numEntries = sPLT_red.length;
for (int i = 0; i < numEntries; i++) {
IIOMetadataNode entry = new IIOMetadataNode("sPLTEntry");
entry.setAttribute("index", Integer.toString(i));
entry.setAttribute("red", Integer.toString(sPLT_red[i]));
entry.setAttribute("green", Integer.toString(sPLT_green[i]));
entry.setAttribute("blue", Integer.toString(sPLT_blue[i]));
entry.setAttribute("alpha", Integer.toString(sPLT_alpha[i]));
entry.setAttribute("frequency",
Integer.toString(sPLT_frequency[i]));
sPLT_node.appendChild(entry);
}
root.appendChild(sPLT_node);
}
// sRGB
if (sRGB_present) {
IIOMetadataNode sRGB_node = new IIOMetadataNode("sRGB");
sRGB_node.setAttribute("renderingIntent",
renderingIntentNames[sRGB_renderingIntent]);
root.appendChild(sRGB_node);
}
// tEXt
if (tEXt_keyword.size() > 0) {
IIOMetadataNode tEXt_parent = new IIOMetadataNode("tEXt");
for (int i = 0; i < tEXt_keyword.size(); i++) {
IIOMetadataNode tEXt_node = new IIOMetadataNode("tEXtEntry");
tEXt_node.setAttribute("keyword" , tEXt_keyword.get(i));
tEXt_node.setAttribute("value" , tEXt_text.get(i));
tEXt_parent.appendChild(tEXt_node);
}
root.appendChild(tEXt_parent);
}
// tIME
if (tIME_present) {
IIOMetadataNode tIME_node = new IIOMetadataNode("tIME");
tIME_node.setAttribute("year", Integer.toString(tIME_year));
tIME_node.setAttribute("month", Integer.toString(tIME_month));
tIME_node.setAttribute("day", Integer.toString(tIME_day));
tIME_node.setAttribute("hour", Integer.toString(tIME_hour));
tIME_node.setAttribute("minute", Integer.toString(tIME_minute));
tIME_node.setAttribute("second", Integer.toString(tIME_second));
root.appendChild(tIME_node);
}
// tRNS
if (tRNS_present) {
IIOMetadataNode tRNS_node = new IIOMetadataNode("tRNS");
if (tRNS_colorType == PNGImageReader.PNG_COLOR_PALETTE) {
node = new IIOMetadataNode("tRNS_Palette");
for (int i = 0; i < tRNS_alpha.length; i++) {
IIOMetadataNode entry =
new IIOMetadataNode("tRNS_PaletteEntry");
entry.setAttribute("index", Integer.toString(i));
entry.setAttribute("alpha",
Integer.toString(tRNS_alpha[i] & 0xff));
node.appendChild(entry);
}
} else if (tRNS_colorType == PNGImageReader.PNG_COLOR_GRAY) {
node = new IIOMetadataNode("tRNS_Grayscale");
node.setAttribute("gray", Integer.toString(tRNS_gray));
} else if (tRNS_colorType == PNGImageReader.PNG_COLOR_RGB) {
node = new IIOMetadataNode("tRNS_RGB");
node.setAttribute("red", Integer.toString(tRNS_red));
node.setAttribute("green", Integer.toString(tRNS_green));
node.setAttribute("blue", Integer.toString(tRNS_blue));
}
tRNS_node.appendChild(node);
root.appendChild(tRNS_node);
}
// zTXt
if (zTXt_keyword.size() > 0) {
IIOMetadataNode zTXt_parent = new IIOMetadataNode("zTXt");
for (int i = 0; i < zTXt_keyword.size(); i++) {
IIOMetadataNode zTXt_node = new IIOMetadataNode("zTXtEntry");
zTXt_node.setAttribute("keyword", zTXt_keyword.get(i));
int cm = (zTXt_compressionMethod.get(i)).intValue();
zTXt_node.setAttribute("compressionMethod",
zTXt_compressionMethodNames[cm]);
zTXt_node.setAttribute("text", zTXt_text.get(i));
zTXt_parent.appendChild(zTXt_node);
}
root.appendChild(zTXt_parent);
}
// Unknown chunks
if (unknownChunkType.size() > 0) {
IIOMetadataNode unknown_parent =
new IIOMetadataNode("UnknownChunks");
for (int i = 0; i < unknownChunkType.size(); i++) {
IIOMetadataNode unknown_node =
new IIOMetadataNode("UnknownChunk");
unknown_node.setAttribute("type",
unknownChunkType.get(i));
unknown_node.setUserObject(unknownChunkData.get(i));
unknown_parent.appendChild(unknown_node);
}
root.appendChild(unknown_parent);
}
return root;
}
private int getNumChannels() {
// Determine number of channels
// Be careful about palette color with transparency
int numChannels = IHDR_numChannels[IHDR_colorType];
if (IHDR_colorType == PNGImageReader.PNG_COLOR_PALETTE &&
tRNS_present && tRNS_colorType == IHDR_colorType) {
numChannels = 4;
}
return numChannels;
}
public IIOMetadataNode getStandardChromaNode() {
IIOMetadataNode chroma_node = new IIOMetadataNode("Chroma");
IIOMetadataNode node = null; // scratch node
node = new IIOMetadataNode("ColorSpaceType");
node.setAttribute("name", colorSpaceTypeNames[IHDR_colorType]);
chroma_node.appendChild(node);
node = new IIOMetadataNode("NumChannels");
node.setAttribute("value", Integer.toString(getNumChannels()));
chroma_node.appendChild(node);
if (gAMA_present) {
node = new IIOMetadataNode("Gamma");
node.setAttribute("value", Float.toString(gAMA_gamma*1.0e-5F));
chroma_node.appendChild(node);
}
node = new IIOMetadataNode("BlackIsZero");
node.setAttribute("value", "TRUE");
chroma_node.appendChild(node);
if (PLTE_present) {
boolean hasAlpha = tRNS_present &&
(tRNS_colorType == PNGImageReader.PNG_COLOR_PALETTE);
node = new IIOMetadataNode("Palette");
for (int i = 0; i < PLTE_red.length; i++) {
IIOMetadataNode entry =
new IIOMetadataNode("PaletteEntry");
entry.setAttribute("index", Integer.toString(i));
entry.setAttribute("red",
Integer.toString(PLTE_red[i] & 0xff));
entry.setAttribute("green",
Integer.toString(PLTE_green[i] & 0xff));
entry.setAttribute("blue",
Integer.toString(PLTE_blue[i] & 0xff));
if (hasAlpha) {
int alpha = (i < tRNS_alpha.length) ?
(tRNS_alpha[i] & 0xff) : 255;
entry.setAttribute("alpha", Integer.toString(alpha));
}
node.appendChild(entry);
}
chroma_node.appendChild(node);
}
if (bKGD_present) {
if (bKGD_colorType == PNGImageReader.PNG_COLOR_PALETTE) {
node = new IIOMetadataNode("BackgroundIndex");
node.setAttribute("value", Integer.toString(bKGD_index));
} else {
node = new IIOMetadataNode("BackgroundColor");
int r, g, b;
if (bKGD_colorType == PNGImageReader.PNG_COLOR_GRAY) {
r = g = b = bKGD_gray;
} else {
r = bKGD_red;
g = bKGD_green;
b = bKGD_blue;
}
node.setAttribute("red", Integer.toString(r));
node.setAttribute("green", Integer.toString(g));
node.setAttribute("blue", Integer.toString(b));
}
chroma_node.appendChild(node);
}
return chroma_node;
}
public IIOMetadataNode getStandardCompressionNode() {
IIOMetadataNode compression_node = new IIOMetadataNode("Compression");
IIOMetadataNode node = null; // scratch node
node = new IIOMetadataNode("CompressionTypeName");
node.setAttribute("value", "deflate");
compression_node.appendChild(node);
node = new IIOMetadataNode("Lossless");
node.setAttribute("value", "TRUE");
compression_node.appendChild(node);
node = new IIOMetadataNode("NumProgressiveScans");
node.setAttribute("value",
(IHDR_interlaceMethod == 0) ? "1" : "7");
compression_node.appendChild(node);
return compression_node;
}
private String repeat(String s, int times) {
if (times == 1) {
return s;
}
StringBuilder sb = new StringBuilder((s.length() + 1)*times - 1);
sb.append(s);
for (int i = 1; i < times; i++) {
sb.append(" ");
sb.append(s);
}
return sb.toString();
}
public IIOMetadataNode getStandardDataNode() {
IIOMetadataNode data_node = new IIOMetadataNode("Data");
IIOMetadataNode node = null; // scratch node
node = new IIOMetadataNode("PlanarConfiguration");
node.setAttribute("value", "PixelInterleaved");
data_node.appendChild(node);
node = new IIOMetadataNode("SampleFormat");
node.setAttribute("value",
IHDR_colorType == PNGImageReader.PNG_COLOR_PALETTE ?
"Index" : "UnsignedIntegral");
data_node.appendChild(node);
String bitDepth = Integer.toString(IHDR_bitDepth);
node = new IIOMetadataNode("BitsPerSample");
node.setAttribute("value", repeat(bitDepth, getNumChannels()));
data_node.appendChild(node);
if (sBIT_present) {
node = new IIOMetadataNode("SignificantBitsPerSample");
String sbits;
if (sBIT_colorType == PNGImageReader.PNG_COLOR_GRAY ||
sBIT_colorType == PNGImageReader.PNG_COLOR_GRAY_ALPHA) {
sbits = Integer.toString(sBIT_grayBits);
} else { // sBIT_colorType == PNGImageReader.PNG_COLOR_RGB ||
// sBIT_colorType == PNGImageReader.PNG_COLOR_RGB_ALPHA
sbits = Integer.toString(sBIT_redBits) + " " +
Integer.toString(sBIT_greenBits) + " " +
Integer.toString(sBIT_blueBits);
}
if (sBIT_colorType == PNGImageReader.PNG_COLOR_GRAY_ALPHA ||
sBIT_colorType == PNGImageReader.PNG_COLOR_RGB_ALPHA) {
sbits += " " + Integer.toString(sBIT_alphaBits);
}
node.setAttribute("value", sbits);
data_node.appendChild(node);
}
// SampleMSB
return data_node;
}
public IIOMetadataNode getStandardDimensionNode() {
IIOMetadataNode dimension_node = new IIOMetadataNode("Dimension");
IIOMetadataNode node = null; // scratch node
node = new IIOMetadataNode("PixelAspectRatio");
float ratio = pHYs_present ?
(float)pHYs_pixelsPerUnitXAxis/pHYs_pixelsPerUnitYAxis : 1.0F;
node.setAttribute("value", Float.toString(ratio));
dimension_node.appendChild(node);
node = new IIOMetadataNode("ImageOrientation");
node.setAttribute("value", "Normal");
dimension_node.appendChild(node);
if (pHYs_present && pHYs_unitSpecifier == PHYS_UNIT_METER) {
node = new IIOMetadataNode("HorizontalPixelSize");
node.setAttribute("value",
Float.toString(1000.0F/pHYs_pixelsPerUnitXAxis));
dimension_node.appendChild(node);
node = new IIOMetadataNode("VerticalPixelSize");
node.setAttribute("value",
Float.toString(1000.0F/pHYs_pixelsPerUnitYAxis));
dimension_node.appendChild(node);
}
return dimension_node;
}
public IIOMetadataNode getStandardDocumentNode() {
IIOMetadataNode document_node = null;
// Check if image modification time exists
if (tIME_present) {
// Create new document node
document_node = new IIOMetadataNode("Document");
// Node to hold image modification time
IIOMetadataNode node = new IIOMetadataNode("ImageModificationTime");
node.setAttribute("year", Integer.toString(tIME_year));
node.setAttribute("month", Integer.toString(tIME_month));
node.setAttribute("day", Integer.toString(tIME_day));
node.setAttribute("hour", Integer.toString(tIME_hour));
node.setAttribute("minute", Integer.toString(tIME_minute));
node.setAttribute("second", Integer.toString(tIME_second));
document_node.appendChild(node);
}
// Check if image creation time exists
if (creation_time_present) {
if (document_node == null) {
// Create new document node
document_node = new IIOMetadataNode("Document");
}
// Node to hold image creation time
IIOMetadataNode node = new IIOMetadataNode("ImageCreationTime");
node.setAttribute("year", Integer.toString(creation_time_year));
node.setAttribute("month", Integer.toString(creation_time_month));
node.setAttribute("day", Integer.toString(creation_time_day));
node.setAttribute("hour", Integer.toString(creation_time_hour));
node.setAttribute("minute", Integer.toString(creation_time_minute));
node.setAttribute("second", Integer.toString(creation_time_second));
document_node.appendChild(node);
}
return document_node;
}
public IIOMetadataNode getStandardTextNode() {
int numEntries = tEXt_keyword.size() +
iTXt_keyword.size() + zTXt_keyword.size();
if (numEntries == 0) {
return null;
}
IIOMetadataNode text_node = new IIOMetadataNode("Text");
IIOMetadataNode node = null; // scratch node
for (int i = 0; i < tEXt_keyword.size(); i++) {
node = new IIOMetadataNode("TextEntry");
node.setAttribute("keyword", tEXt_keyword.get(i));
node.setAttribute("value", tEXt_text.get(i));
node.setAttribute("encoding", "ISO-8859-1");
node.setAttribute("compression", "none");
text_node.appendChild(node);
}
for (int i = 0; i < iTXt_keyword.size(); i++) {
node = new IIOMetadataNode("TextEntry");
node.setAttribute("keyword", iTXt_keyword.get(i));
node.setAttribute("value", iTXt_text.get(i));
node.setAttribute("language",
iTXt_languageTag.get(i));
if (iTXt_compressionFlag.get(i)) {
node.setAttribute("compression", "zip");
} else {
node.setAttribute("compression", "none");
}
text_node.appendChild(node);
}
for (int i = 0; i < zTXt_keyword.size(); i++) {
node = new IIOMetadataNode("TextEntry");
node.setAttribute("keyword", zTXt_keyword.get(i));
node.setAttribute("value", zTXt_text.get(i));
node.setAttribute("compression", "zip");
text_node.appendChild(node);
}
return text_node;
}
public IIOMetadataNode getStandardTransparencyNode() {
IIOMetadataNode transparency_node =
new IIOMetadataNode("Transparency");
IIOMetadataNode node = null; // scratch node
node = new IIOMetadataNode("Alpha");
boolean hasAlpha =
(IHDR_colorType == PNGImageReader.PNG_COLOR_RGB_ALPHA) ||
(IHDR_colorType == PNGImageReader.PNG_COLOR_GRAY_ALPHA) ||
(IHDR_colorType == PNGImageReader.PNG_COLOR_PALETTE &&
tRNS_present &&
(tRNS_colorType == IHDR_colorType) &&
(tRNS_alpha != null));
node.setAttribute("value", hasAlpha ? "nonpremultipled" : "none");
transparency_node.appendChild(node);
if (tRNS_present) {
node = new IIOMetadataNode("TransparentColor");
if (tRNS_colorType == PNGImageReader.PNG_COLOR_RGB) {
node.setAttribute("value",
Integer.toString(tRNS_red) + " " +
Integer.toString(tRNS_green) + " " +
Integer.toString(tRNS_blue));
} else if (tRNS_colorType == PNGImageReader.PNG_COLOR_GRAY) {
node.setAttribute("value", Integer.toString(tRNS_gray));
}
transparency_node.appendChild(node);
}
return transparency_node;
}
// Shorthand for throwing an IIOInvalidTreeException
private void fatal(Node node, String reason)
throws IIOInvalidTreeException {
throw new IIOInvalidTreeException(reason, node);
}
// Get an integer-valued attribute
private String getStringAttribute(Node node, String name,
String defaultValue, boolean required)
throws IIOInvalidTreeException {
Node attr = node.getAttributes().getNamedItem(name);
if (attr == null) {
if (!required) {
return defaultValue;
} else {
fatal(node, "Required attribute " + name + " not present!");
}
}
return attr.getNodeValue();
}
// Get an integer-valued attribute
private int getIntAttribute(Node node, String name,
int defaultValue, boolean required)
throws IIOInvalidTreeException {
String value = getStringAttribute(node, name, null, required);
if (value == null) {
return defaultValue;
}
return Integer.parseInt(value);
}
// Get a float-valued attribute
private float getFloatAttribute(Node node, String name,
float defaultValue, boolean required)
throws IIOInvalidTreeException {
String value = getStringAttribute(node, name, null, required);
if (value == null) {
return defaultValue;
}
return Float.parseFloat(value);
}
// Get a required integer-valued attribute
private int getIntAttribute(Node node, String name)
throws IIOInvalidTreeException {
return getIntAttribute(node, name, -1, true);
}
// Get a required float-valued attribute
private float getFloatAttribute(Node node, String name)
throws IIOInvalidTreeException {
return getFloatAttribute(node, name, -1.0F, true);
}
// Get a boolean-valued attribute
private boolean getBooleanAttribute(Node node, String name,
boolean defaultValue,
boolean required)
throws IIOInvalidTreeException {
Node attr = node.getAttributes().getNamedItem(name);
if (attr == null) {
if (!required) {
return defaultValue;
} else {
fatal(node, "Required attribute " + name + " not present!");
}
}
String value = attr.getNodeValue();
// Allow lower case booleans for backward compatibility, #5082756
if (value.equals("TRUE") || value.equals("true")) {
return true;
} else if (value.equals("FALSE") || value.equals("false")) {
return false;
} else {
fatal(node, "Attribute " + name + " must be 'TRUE' or 'FALSE'!");
return false;
}
}
// Get a required boolean-valued attribute
private boolean getBooleanAttribute(Node node, String name)
throws IIOInvalidTreeException {
return getBooleanAttribute(node, name, false, true);
}
// Get an enumerated attribute as an index into a String array
private int getEnumeratedAttribute(Node node,
String name, String[] legalNames,
int defaultValue, boolean required)
throws IIOInvalidTreeException {
Node attr = node.getAttributes().getNamedItem(name);
if (attr == null) {
if (!required) {
return defaultValue;
} else {
fatal(node, "Required attribute " + name + " not present!");
}
}
String value = attr.getNodeValue();
for (int i = 0; i < legalNames.length; i++) {
if (value.equals(legalNames[i])) {
return i;
}
}
fatal(node, "Illegal value for attribute " + name + "!");
return -1;
}
// Get a required enumerated attribute as an index into a String array
private int getEnumeratedAttribute(Node node,
String name, String[] legalNames)
throws IIOInvalidTreeException {
return getEnumeratedAttribute(node, name, legalNames, -1, true);
}
// Get a String-valued attribute
private String getAttribute(Node node, String name,
String defaultValue, boolean required)
throws IIOInvalidTreeException {
Node attr = node.getAttributes().getNamedItem(name);
if (attr == null) {
if (!required) {
return defaultValue;
} else {
fatal(node, "Required attribute " + name + " not present!");
}
}
return attr.getNodeValue();
}
// Get a required String-valued attribute
private String getAttribute(Node node, String name)
throws IIOInvalidTreeException {
return getAttribute(node, name, null, true);
}
public void mergeTree(String formatName, Node root)
throws IIOInvalidTreeException {
if (formatName.equals(nativeMetadataFormatName)) {
if (root == null) {
throw new IllegalArgumentException("root == null!");
}
mergeNativeTree(root);
} else if (formatName.equals
(IIOMetadataFormatImpl.standardMetadataFormatName)) {
if (root == null) {
throw new IllegalArgumentException("root == null!");
}
mergeStandardTree(root);
} else {
throw new IllegalArgumentException("Not a recognized format!");
}
}
private void mergeNativeTree(Node root)
throws IIOInvalidTreeException {
Node node = root;
if (!node.getNodeName().equals(nativeMetadataFormatName)) {
fatal(node, "Root must be " + nativeMetadataFormatName);
}
node = node.getFirstChild();
while (node != null) {
String name = node.getNodeName();
if (name.equals("IHDR")) {
IHDR_width = getIntAttribute(node, "width");
IHDR_height = getIntAttribute(node, "height");
IHDR_bitDepth =
Integer.valueOf(IHDR_bitDepths[
getEnumeratedAttribute(node,
"bitDepth",
IHDR_bitDepths)]);
IHDR_colorType = getEnumeratedAttribute(node, "colorType",
IHDR_colorTypeNames);
IHDR_compressionMethod =
getEnumeratedAttribute(node, "compressionMethod",
IHDR_compressionMethodNames);
IHDR_filterMethod =
getEnumeratedAttribute(node,
"filterMethod",
IHDR_filterMethodNames);
IHDR_interlaceMethod =
getEnumeratedAttribute(node, "interlaceMethod",
IHDR_interlaceMethodNames);
IHDR_present = true;
} else if (name.equals("PLTE")) {
byte[] red = new byte[256];
byte[] green = new byte[256];
byte[] blue = new byte[256];
int maxindex = -1;
Node PLTE_entry = node.getFirstChild();
if (PLTE_entry == null) {
fatal(node, "Palette has no entries!");
}
while (PLTE_entry != null) {
if (!PLTE_entry.getNodeName().equals("PLTEEntry")) {
fatal(node,
"Only a PLTEEntry may be a child of a PLTE!");
}
int index = getIntAttribute(PLTE_entry, "index");
if (index < 0 || index > 255) {
fatal(node,
"Bad value for PLTEEntry attribute index!");
}
if (index > maxindex) {
maxindex = index;
}
red[index] =
(byte)getIntAttribute(PLTE_entry, "red");
green[index] =
(byte)getIntAttribute(PLTE_entry, "green");
blue[index] =
(byte)getIntAttribute(PLTE_entry, "blue");
PLTE_entry = PLTE_entry.getNextSibling();
}
int numEntries = maxindex + 1;
PLTE_red = new byte[numEntries];
PLTE_green = new byte[numEntries];
PLTE_blue = new byte[numEntries];
System.arraycopy(red, 0, PLTE_red, 0, numEntries);
System.arraycopy(green, 0, PLTE_green, 0, numEntries);
System.arraycopy(blue, 0, PLTE_blue, 0, numEntries);
PLTE_present = true;
} else if (name.equals("bKGD")) {
bKGD_present = false; // Guard against partial overwrite
Node bKGD_node = node.getFirstChild();
if (bKGD_node == null) {
fatal(node, "bKGD node has no children!");
}
String bKGD_name = bKGD_node.getNodeName();
if (bKGD_name.equals("bKGD_Palette")) {
bKGD_index = getIntAttribute(bKGD_node, "index");
bKGD_colorType = PNGImageReader.PNG_COLOR_PALETTE;
} else if (bKGD_name.equals("bKGD_Grayscale")) {
bKGD_gray = getIntAttribute(bKGD_node, "gray");
bKGD_colorType = PNGImageReader.PNG_COLOR_GRAY;
} else if (bKGD_name.equals("bKGD_RGB")) {
bKGD_red = getIntAttribute(bKGD_node, "red");
bKGD_green = getIntAttribute(bKGD_node, "green");
bKGD_blue = getIntAttribute(bKGD_node, "blue");
bKGD_colorType = PNGImageReader.PNG_COLOR_RGB;
} else {
fatal(node, "Bad child of a bKGD node!");
}
if (bKGD_node.getNextSibling() != null) {
fatal(node, "bKGD node has more than one child!");
}
bKGD_present = true;
} else if (name.equals("cHRM")) {
cHRM_whitePointX = getIntAttribute(node, "whitePointX");
cHRM_whitePointY = getIntAttribute(node, "whitePointY");
cHRM_redX = getIntAttribute(node, "redX");
cHRM_redY = getIntAttribute(node, "redY");
cHRM_greenX = getIntAttribute(node, "greenX");
cHRM_greenY = getIntAttribute(node, "greenY");
cHRM_blueX = getIntAttribute(node, "blueX");
cHRM_blueY = getIntAttribute(node, "blueY");
cHRM_present = true;
} else if (name.equals("gAMA")) {
gAMA_gamma = getIntAttribute(node, "value");
gAMA_present = true;
} else if (name.equals("hIST")) {
char[] hist = new char[256];
int maxindex = -1;
Node hIST_entry = node.getFirstChild();
if (hIST_entry == null) {
fatal(node, "hIST node has no children!");
}
while (hIST_entry != null) {
if (!hIST_entry.getNodeName().equals("hISTEntry")) {
fatal(node,
"Only a hISTEntry may be a child of a hIST!");
}
int index = getIntAttribute(hIST_entry, "index");
if (index < 0 || index > 255) {
fatal(node,
"Bad value for histEntry attribute index!");
}
if (index > maxindex) {
maxindex = index;
}
hist[index] =
(char)getIntAttribute(hIST_entry, "value");
hIST_entry = hIST_entry.getNextSibling();
}
int numEntries = maxindex + 1;
hIST_histogram = new char[numEntries];
System.arraycopy(hist, 0, hIST_histogram, 0, numEntries);
hIST_present = true;
} else if (name.equals("iCCP")) {
iCCP_profileName = getAttribute(node, "profileName");
iCCP_compressionMethod =
getEnumeratedAttribute(node, "compressionMethod",
iCCP_compressionMethodNames);
Object compressedProfile =
((IIOMetadataNode)node).getUserObject();
if (compressedProfile == null) {
fatal(node, "No ICCP profile present in user object!");
}
if (!(compressedProfile instanceof byte[])) {
fatal(node, "User object not a byte array!");
}
iCCP_compressedProfile = ((byte[])compressedProfile).clone();
iCCP_present = true;
} else if (name.equals("iTXt")) {
Node iTXt_node = node.getFirstChild();
while (iTXt_node != null) {
if (!iTXt_node.getNodeName().equals("iTXtEntry")) {
fatal(node,
"Only an iTXtEntry may be a child of an iTXt!");
}
String keyword = getAttribute(iTXt_node, "keyword");
if (isValidKeyword(keyword)) {
iTXt_keyword.add(keyword);
boolean compressionFlag =
getBooleanAttribute(iTXt_node, "compressionFlag");
iTXt_compressionFlag.add(Boolean.valueOf(compressionFlag));
String compressionMethod =
getAttribute(iTXt_node, "compressionMethod");
iTXt_compressionMethod.add(Integer.valueOf(compressionMethod));
String languageTag =
getAttribute(iTXt_node, "languageTag");
iTXt_languageTag.add(languageTag);
String translatedKeyword =
getAttribute(iTXt_node, "translatedKeyword");
iTXt_translatedKeyword.add(translatedKeyword);
String text = getAttribute(iTXt_node, "text");
iTXt_text.add(text);
// Check if the text chunk contains image creation time
if (keyword.equals(PNGMetadata.tEXt_creationTimeKey)) {
// Update Standard/Document/ImageCreationTime
int index = iTXt_text.size()-1;
decodeImageCreationTimeFromTextChunk(
iTXt_text.listIterator(index));
}
}
// silently skip invalid text entry
iTXt_node = iTXt_node.getNextSibling();
}
} else if (name.equals("pHYs")) {
pHYs_pixelsPerUnitXAxis =
getIntAttribute(node, "pixelsPerUnitXAxis");
pHYs_pixelsPerUnitYAxis =
getIntAttribute(node, "pixelsPerUnitYAxis");
pHYs_unitSpecifier =
getEnumeratedAttribute(node, "unitSpecifier",
unitSpecifierNames);
pHYs_present = true;
} else if (name.equals("sBIT")) {
sBIT_present = false; // Guard against partial overwrite
Node sBIT_node = node.getFirstChild();
if (sBIT_node == null) {
fatal(node, "sBIT node has no children!");
}
String sBIT_name = sBIT_node.getNodeName();
if (sBIT_name.equals("sBIT_Grayscale")) {
sBIT_grayBits = getIntAttribute(sBIT_node, "gray");
sBIT_colorType = PNGImageReader.PNG_COLOR_GRAY;
} else if (sBIT_name.equals("sBIT_GrayAlpha")) {
sBIT_grayBits = getIntAttribute(sBIT_node, "gray");
sBIT_alphaBits = getIntAttribute(sBIT_node, "alpha");
sBIT_colorType = PNGImageReader.PNG_COLOR_GRAY_ALPHA;
} else if (sBIT_name.equals("sBIT_RGB")) {
sBIT_redBits = getIntAttribute(sBIT_node, "red");
sBIT_greenBits = getIntAttribute(sBIT_node, "green");
sBIT_blueBits = getIntAttribute(sBIT_node, "blue");
sBIT_colorType = PNGImageReader.PNG_COLOR_RGB;
} else if (sBIT_name.equals("sBIT_RGBAlpha")) {
sBIT_redBits = getIntAttribute(sBIT_node, "red");
sBIT_greenBits = getIntAttribute(sBIT_node, "green");
sBIT_blueBits = getIntAttribute(sBIT_node, "blue");
sBIT_alphaBits = getIntAttribute(sBIT_node, "alpha");
sBIT_colorType = PNGImageReader.PNG_COLOR_RGB_ALPHA;
} else if (sBIT_name.equals("sBIT_Palette")) {
sBIT_redBits = getIntAttribute(sBIT_node, "red");
sBIT_greenBits = getIntAttribute(sBIT_node, "green");
sBIT_blueBits = getIntAttribute(sBIT_node, "blue");
sBIT_colorType = PNGImageReader.PNG_COLOR_PALETTE;
} else {
fatal(node, "Bad child of an sBIT node!");
}
if (sBIT_node.getNextSibling() != null) {
fatal(node, "sBIT node has more than one child!");
}
sBIT_present = true;
} else if (name.equals("sPLT")) {
sPLT_paletteName = getAttribute(node, "name");
sPLT_sampleDepth = getIntAttribute(node, "sampleDepth");
int[] red = new int[256];
int[] green = new int[256];
int[] blue = new int[256];
int[] alpha = new int[256];
int[] frequency = new int[256];
int maxindex = -1;
Node sPLT_entry = node.getFirstChild();
if (sPLT_entry == null) {
fatal(node, "sPLT node has no children!");
}
while (sPLT_entry != null) {
if (!sPLT_entry.getNodeName().equals("sPLTEntry")) {
fatal(node,
"Only an sPLTEntry may be a child of an sPLT!");
}
int index = getIntAttribute(sPLT_entry, "index");
if (index < 0 || index > 255) {
fatal(node,
"Bad value for PLTEEntry attribute index!");
}
if (index > maxindex) {
maxindex = index;
}
red[index] = getIntAttribute(sPLT_entry, "red");
green[index] = getIntAttribute(sPLT_entry, "green");
blue[index] = getIntAttribute(sPLT_entry, "blue");
alpha[index] = getIntAttribute(sPLT_entry, "alpha");
frequency[index] =
getIntAttribute(sPLT_entry, "frequency");
sPLT_entry = sPLT_entry.getNextSibling();
}
int numEntries = maxindex + 1;
sPLT_red = new int[numEntries];
sPLT_green = new int[numEntries];
sPLT_blue = new int[numEntries];
sPLT_alpha = new int[numEntries];
sPLT_frequency = new int[numEntries];
System.arraycopy(red, 0, sPLT_red, 0, numEntries);
System.arraycopy(green, 0, sPLT_green, 0, numEntries);
System.arraycopy(blue, 0, sPLT_blue, 0, numEntries);
System.arraycopy(alpha, 0, sPLT_alpha, 0, numEntries);
System.arraycopy(frequency, 0,
sPLT_frequency, 0, numEntries);
sPLT_present = true;
} else if (name.equals("sRGB")) {
sRGB_renderingIntent =
getEnumeratedAttribute(node, "renderingIntent",
renderingIntentNames);
sRGB_present = true;
} else if (name.equals("tEXt")) {
Node tEXt_node = node.getFirstChild();
while (tEXt_node != null) {
if (!tEXt_node.getNodeName().equals("tEXtEntry")) {
fatal(node,
"Only an tEXtEntry may be a child of an tEXt!");
}
String keyword = getAttribute(tEXt_node, "keyword");
tEXt_keyword.add(keyword);
String text = getAttribute(tEXt_node, "value");
tEXt_text.add(text);
// Check if the text chunk contains image creation time
if (keyword.equals(PNGMetadata.tEXt_creationTimeKey)) {
// Update Standard/Document/ImageCreationTime
int index = tEXt_text.size()-1;
decodeImageCreationTimeFromTextChunk(
tEXt_text.listIterator(index));
}
tEXt_node = tEXt_node.getNextSibling();
}
} else if (name.equals("tIME")) {
tIME_year = getIntAttribute(node, "year");
tIME_month = getIntAttribute(node, "month");
tIME_day = getIntAttribute(node, "day");
tIME_hour = getIntAttribute(node, "hour");
tIME_minute = getIntAttribute(node, "minute");
tIME_second = getIntAttribute(node, "second");
tIME_present = true;
} else if (name.equals("tRNS")) {
tRNS_present = false; // Guard against partial overwrite
Node tRNS_node = node.getFirstChild();
if (tRNS_node == null) {
fatal(node, "tRNS node has no children!");
}
String tRNS_name = tRNS_node.getNodeName();
if (tRNS_name.equals("tRNS_Palette")) {
byte[] alpha = new byte[256];
int maxindex = -1;
Node tRNS_paletteEntry = tRNS_node.getFirstChild();
if (tRNS_paletteEntry == null) {
fatal(node, "tRNS_Palette node has no children!");
}
while (tRNS_paletteEntry != null) {
if (!tRNS_paletteEntry.getNodeName().equals(
"tRNS_PaletteEntry")) {
fatal(node,
"Only a tRNS_PaletteEntry may be a child of a tRNS_Palette!");
}
int index =
getIntAttribute(tRNS_paletteEntry, "index");
if (index < 0 || index > 255) {
fatal(node,
"Bad value for tRNS_PaletteEntry attribute index!");
}
if (index > maxindex) {
maxindex = index;
}
alpha[index] =
(byte)getIntAttribute(tRNS_paletteEntry,
"alpha");
tRNS_paletteEntry =
tRNS_paletteEntry.getNextSibling();
}
int numEntries = maxindex + 1;
tRNS_alpha = new byte[numEntries];
tRNS_colorType = PNGImageReader.PNG_COLOR_PALETTE;
System.arraycopy(alpha, 0, tRNS_alpha, 0, numEntries);
} else if (tRNS_name.equals("tRNS_Grayscale")) {
tRNS_gray = getIntAttribute(tRNS_node, "gray");
tRNS_colorType = PNGImageReader.PNG_COLOR_GRAY;
} else if (tRNS_name.equals("tRNS_RGB")) {
tRNS_red = getIntAttribute(tRNS_node, "red");
tRNS_green = getIntAttribute(tRNS_node, "green");
tRNS_blue = getIntAttribute(tRNS_node, "blue");
tRNS_colorType = PNGImageReader.PNG_COLOR_RGB;
} else {
fatal(node, "Bad child of a tRNS node!");
}
if (tRNS_node.getNextSibling() != null) {
fatal(node, "tRNS node has more than one child!");
}
tRNS_present = true;
} else if (name.equals("zTXt")) {
Node zTXt_node = node.getFirstChild();
while (zTXt_node != null) {
if (!zTXt_node.getNodeName().equals("zTXtEntry")) {
fatal(node,
"Only an zTXtEntry may be a child of an zTXt!");
}
String keyword = getAttribute(zTXt_node, "keyword");
zTXt_keyword.add(keyword);
int compressionMethod =
getEnumeratedAttribute(zTXt_node, "compressionMethod",
zTXt_compressionMethodNames);
zTXt_compressionMethod.add(compressionMethod);
String text = getAttribute(zTXt_node, "text");
zTXt_text.add(text);
// Check if the text chunk contains image creation time
if (keyword.equals(PNGMetadata.tEXt_creationTimeKey)) {
// Update Standard/Document/ImageCreationTime
int index = zTXt_text.size()-1;
decodeImageCreationTimeFromTextChunk(
zTXt_text.listIterator(index));
}
zTXt_node = zTXt_node.getNextSibling();
}
} else if (name.equals("UnknownChunks")) {
Node unknown_node = node.getFirstChild();
while (unknown_node != null) {
if (!unknown_node.getNodeName().equals("UnknownChunk")) {
fatal(node,
"Only an UnknownChunk may be a child of an UnknownChunks!");
}
String chunkType = getAttribute(unknown_node, "type");
Object chunkData =
((IIOMetadataNode)unknown_node).getUserObject();
if (chunkType.length() != 4) {
fatal(unknown_node,
"Chunk type must be 4 characters!");
}
if (chunkData == null) {
fatal(unknown_node,
"No chunk data present in user object!");
}
if (!(chunkData instanceof byte[])) {
fatal(unknown_node,
"User object not a byte array!");
}
unknownChunkType.add(chunkType);
unknownChunkData.add(((byte[])chunkData).clone());
unknown_node = unknown_node.getNextSibling();
}
} else {
fatal(node, "Unknown child of root node!");
}
node = node.getNextSibling();
}
}
/*
* Accrding to PNG spec, keywords are restricted to 1 to 79 bytes
* in length. Keywords shall contain only printable Latin-1 characters
* and spaces; To reduce the chances for human misreading of a keyword,
* leading spaces, trailing spaces, and consecutive spaces are not
* permitted in keywords.
*
* See: http://www.w3.org/TR/PNG/#11keywords
*/
private boolean isValidKeyword(String s) {
int len = s.length();
if (len < 1 || len >= 80) {
return false;
}
if (s.startsWith(" ") || s.endsWith(" ") || s.contains(" ")) {
return false;
}
return isISOLatin(s, false);
}
/*
* According to PNG spec, keyword shall contain only printable
* Latin-1 [ISO-8859-1] characters and spaces; that is, only
* character codes 32-126 and 161-255 decimal are allowed.
* For Latin-1 value fields the 0x10 (linefeed) control
* character is aloowed too.
*
* See: http://www.w3.org/TR/PNG/#11keywords
*/
private boolean isISOLatin(String s, boolean isLineFeedAllowed) {
int len = s.length();
for (int i = 0; i < len; i++) {
char c = s.charAt(i);
if (c < 32 || c > 255 || (c > 126 && c < 161)) {
// not printable. Check whether this is an allowed
// control char
if (!isLineFeedAllowed || c != 0x10) {
return false;
}
}
}
return true;
}
private void mergeStandardTree(Node root)
throws IIOInvalidTreeException {
Node node = root;
if (!node.getNodeName()
.equals(IIOMetadataFormatImpl.standardMetadataFormatName)) {
fatal(node, "Root must be " +
IIOMetadataFormatImpl.standardMetadataFormatName);
}
node = node.getFirstChild();
while (node != null) {
String name = node.getNodeName();
if (name.equals("Chroma")) {
Node child = node.getFirstChild();
while (child != null) {
String childName = child.getNodeName();
if (childName.equals("Gamma")) {
float gamma = getFloatAttribute(child, "value");
gAMA_present = true;
gAMA_gamma = (int)(gamma*100000 + 0.5);
} else if (childName.equals("Palette")) {
byte[] red = new byte[256];
byte[] green = new byte[256];
byte[] blue = new byte[256];
int maxindex = -1;
Node entry = child.getFirstChild();
while (entry != null) {
int index = getIntAttribute(entry, "index");
if (index >= 0 && index <= 255) {
red[index] =
(byte)getIntAttribute(entry, "red");
green[index] =
(byte)getIntAttribute(entry, "green");
blue[index] =
(byte)getIntAttribute(entry, "blue");
if (index > maxindex) {
maxindex = index;
}
}
entry = entry.getNextSibling();
}
int numEntries = maxindex + 1;
PLTE_red = new byte[numEntries];
PLTE_green = new byte[numEntries];
PLTE_blue = new byte[numEntries];
System.arraycopy(red, 0, PLTE_red, 0, numEntries);
System.arraycopy(green, 0, PLTE_green, 0, numEntries);
System.arraycopy(blue, 0, PLTE_blue, 0, numEntries);
PLTE_present = true;
} else if (childName.equals("BackgroundIndex")) {
bKGD_present = true;
bKGD_colorType = PNGImageReader.PNG_COLOR_PALETTE;
bKGD_index = getIntAttribute(child, "value");
} else if (childName.equals("BackgroundColor")) {
int red = getIntAttribute(child, "red");
int green = getIntAttribute(child, "green");
int blue = getIntAttribute(child, "blue");
if (red == green && red == blue) {
bKGD_colorType = PNGImageReader.PNG_COLOR_GRAY;
bKGD_gray = red;
} else {
bKGD_red = red;
bKGD_green = green;
bKGD_blue = blue;
}
bKGD_present = true;
}
// } else if (childName.equals("ColorSpaceType")) {
// } else if (childName.equals("NumChannels")) {
child = child.getNextSibling();
}
} else if (name.equals("Compression")) {
Node child = node.getFirstChild();
while (child != null) {
String childName = child.getNodeName();
if (childName.equals("NumProgressiveScans")) {
// Use Adam7 if NumProgressiveScans > 1
int scans = getIntAttribute(child, "value");
IHDR_interlaceMethod = (scans > 1) ? 1 : 0;
// } else if (childName.equals("CompressionTypeName")) {
// } else if (childName.equals("Lossless")) {
// } else if (childName.equals("BitRate")) {
}
child = child.getNextSibling();
}
} else if (name.equals("Data")) {
Node child = node.getFirstChild();
while (child != null) {
String childName = child.getNodeName();
if (childName.equals("BitsPerSample")) {
String s = getAttribute(child, "value");
StringTokenizer t = new StringTokenizer(s);
int maxBits = -1;
while (t.hasMoreTokens()) {
int bits = Integer.parseInt(t.nextToken());
if (bits > maxBits) {
maxBits = bits;
}
}
if (maxBits < 1) {
maxBits = 1;
}
if (maxBits == 3) maxBits = 4;
if (maxBits > 4 || maxBits < 8) {
maxBits = 8;
}
if (maxBits > 8) {
maxBits = 16;
}
IHDR_bitDepth = maxBits;
} else if (childName.equals("SignificantBitsPerSample")) {
String s = getAttribute(child, "value");
StringTokenizer t = new StringTokenizer(s);
int numTokens = t.countTokens();
if (numTokens == 1) {
sBIT_colorType = PNGImageReader.PNG_COLOR_GRAY;
sBIT_grayBits = Integer.parseInt(t.nextToken());
} else if (numTokens == 2) {
sBIT_colorType =
PNGImageReader.PNG_COLOR_GRAY_ALPHA;
sBIT_grayBits = Integer.parseInt(t.nextToken());
sBIT_alphaBits = Integer.parseInt(t.nextToken());
} else if (numTokens == 3) {
sBIT_colorType = PNGImageReader.PNG_COLOR_RGB;
sBIT_redBits = Integer.parseInt(t.nextToken());
sBIT_greenBits = Integer.parseInt(t.nextToken());
sBIT_blueBits = Integer.parseInt(t.nextToken());
} else if (numTokens == 4) {
sBIT_colorType =
PNGImageReader.PNG_COLOR_RGB_ALPHA;
sBIT_redBits = Integer.parseInt(t.nextToken());
sBIT_greenBits = Integer.parseInt(t.nextToken());
sBIT_blueBits = Integer.parseInt(t.nextToken());
sBIT_alphaBits = Integer.parseInt(t.nextToken());
}
if (numTokens >= 1 && numTokens <= 4) {
sBIT_present = true;
}
// } else if (childName.equals("PlanarConfiguration")) {
// } else if (childName.equals("SampleFormat")) {
// } else if (childName.equals("SampleMSB")) {
}
child = child.getNextSibling();
}
} else if (name.equals("Dimension")) {
boolean gotWidth = false;
boolean gotHeight = false;
boolean gotAspectRatio = false;
float width = -1.0F;
float height = -1.0F;
float aspectRatio = -1.0F;
Node child = node.getFirstChild();
while (child != null) {
String childName = child.getNodeName();
if (childName.equals("PixelAspectRatio")) {
aspectRatio = getFloatAttribute(child, "value");
gotAspectRatio = true;
} else if (childName.equals("HorizontalPixelSize")) {
width = getFloatAttribute(child, "value");
gotWidth = true;
} else if (childName.equals("VerticalPixelSize")) {
height = getFloatAttribute(child, "value");
gotHeight = true;
// } else if (childName.equals("ImageOrientation")) {
// } else if
// (childName.equals("HorizontalPhysicalPixelSpacing")) {
// } else if
// (childName.equals("VerticalPhysicalPixelSpacing")) {
// } else if (childName.equals("HorizontalPosition")) {
// } else if (childName.equals("VerticalPosition")) {
// } else if (childName.equals("HorizontalPixelOffset")) {
// } else if (childName.equals("VerticalPixelOffset")) {
}
child = child.getNextSibling();
}
if (gotWidth && gotHeight) {
pHYs_present = true;
pHYs_unitSpecifier = 1;
pHYs_pixelsPerUnitXAxis = (int)(width*1000 + 0.5F);
pHYs_pixelsPerUnitYAxis = (int)(height*1000 + 0.5F);
} else if (gotAspectRatio) {
pHYs_present = true;
pHYs_unitSpecifier = 0;
// Find a reasonable rational approximation
int denom = 1;
for (; denom < 100; denom++) {
int num = (int)(aspectRatio*denom);
if (Math.abs(num/denom - aspectRatio) < 0.001) {
break;
}
}
pHYs_pixelsPerUnitXAxis = (int)(aspectRatio*denom);
pHYs_pixelsPerUnitYAxis = denom;
}
} else if (name.equals("Document")) {
Node child = node.getFirstChild();
while (child != null) {
String childName = child.getNodeName();
if (childName.equals("ImageModificationTime")) {
tIME_present = true;
tIME_year = getIntAttribute(child, "year");
tIME_month = getIntAttribute(child, "month");
tIME_day = getIntAttribute(child, "day");
tIME_hour =
getIntAttribute(child, "hour", 0, false);
tIME_minute =
getIntAttribute(child, "minute", 0, false);
tIME_second =
getIntAttribute(child, "second", 0, false);
// } else if (childName.equals("SubimageInterpretation")) {
} else if (childName.equals("ImageCreationTime")) {
// Extract the creation time values
int year = getIntAttribute(child, "year");
int month = getIntAttribute(child, "month");
int day = getIntAttribute(child, "day");
int hour = getIntAttribute(child, "hour", 0, false);
int mins = getIntAttribute(child, "minute", 0, false);
int sec = getIntAttribute(child, "second", 0, false);
/*
* Update Standard/Document/ImageCreationTime and encode
* the same in the last decoded text chunk with creation
* time
*/
initImageCreationTime(year, month, day, hour, mins, sec);
encodeImageCreationTimeToTextChunk();
}
child = child.getNextSibling();
}
} else if (name.equals("Text")) {
Node child = node.getFirstChild();
while (child != null) {
String childName = child.getNodeName();
if (childName.equals("TextEntry")) {
String keyword =
getAttribute(child, "keyword", "", false);
String value = getAttribute(child, "value");
String language =
getAttribute(child, "language", "", false);
String compression =
getAttribute(child, "compression", "none", false);
if (!isValidKeyword(keyword)) {
// Just ignore this node, PNG requires keywords
} else if (isISOLatin(value, true)) {
if (compression.equals("zip")) {
// Use a zTXt node
zTXt_keyword.add(keyword);
zTXt_text.add(value);
zTXt_compressionMethod.add(Integer.valueOf(0));
} else {
// Use a tEXt node
tEXt_keyword.add(keyword);
tEXt_text.add(value);
}
} else {
// Use an iTXt node
iTXt_keyword.add(keyword);
iTXt_compressionFlag.add(Boolean.valueOf(compression.equals("zip")));
iTXt_compressionMethod.add(Integer.valueOf(0));
iTXt_languageTag.add(language);
iTXt_translatedKeyword.add(keyword); // fake it
iTXt_text.add(value);
}
}
child = child.getNextSibling();
}
// } else if (name.equals("Transparency")) {
// Node child = node.getFirstChild();
// while (child != null) {
// String childName = child.getNodeName();
// if (childName.equals("Alpha")) {
// } else if (childName.equals("TransparentIndex")) {
// } else if (childName.equals("TransparentColor")) {
// } else if (childName.equals("TileTransparencies")) {
// } else if (childName.equals("TileOpacities")) {
// }
// child = child.getNextSibling();
// }
// } else {
// // fatal(node, "Unknown child of root node!");
}
node = node.getNextSibling();
}
}
void initImageCreationTime(OffsetDateTime offsetDateTime) {
// Check for incoming arguments
if (offsetDateTime != null) {
// set values that make up Standard/Document/ImageCreationTime
creation_time_present = true;
creation_time_year = offsetDateTime.getYear();
creation_time_month = offsetDateTime.getMonthValue();
creation_time_day = offsetDateTime.getDayOfMonth();
creation_time_hour = offsetDateTime.getHour();
creation_time_minute = offsetDateTime.getMinute();
creation_time_second = offsetDateTime.getSecond();
creation_time_offset = offsetDateTime.getOffset();
}
}
void initImageCreationTime(int year, int month, int day,
int hour, int min,int second) {
/*
* Though LocalDateTime suffices the need to store Standard/Document/
* ImageCreationTime, we require the zone offset to encode the same
* in the text chunk based on RFC1123 format.
*/
LocalDateTime locDT = LocalDateTime.of(year, month, day, hour, min, second);
ZoneOffset offset = ZoneId.systemDefault()
.getRules()
.getOffset(locDT);
OffsetDateTime offDateTime = OffsetDateTime.of(locDT,offset);
initImageCreationTime(offDateTime);
}
void decodeImageCreationTimeFromTextChunk(ListIterator<String> iterChunk) {
// Check for incoming arguments
if (iterChunk != null && iterChunk.hasNext()) {
/*
* Save the iterator to mark the last decoded text chunk with
* creation time. The contents of this chunk will be updated when
* user provides creation time by merging a standard tree with
* Standard/Document/ImageCreationTime.
*/
setCreationTimeChunk(iterChunk);
// Parse encoded time and set Standard/Document/ImageCreationTime.
String encodedTime = getEncodedTime();
initImageCreationTime(parseEncodedTime(encodedTime));
}
}
void encodeImageCreationTimeToTextChunk() {
// Check if Standard/Document/ImageCreationTime exists.
if (creation_time_present) {
// Check if a text chunk with creation time exists.
if (tEXt_creation_time_present == false) {
// No text chunk exists with image creation time. Add an entry.
this.tEXt_keyword.add(tEXt_creationTimeKey);
this.tEXt_text.add("Creation Time Place Holder");
// Update the iterator
int index = tEXt_text.size() - 1;
setCreationTimeChunk(tEXt_text.listIterator(index));
}
// Encode image creation time with RFC1123 formatter
OffsetDateTime offDateTime = OffsetDateTime.of(creation_time_year,
creation_time_month, creation_time_day,
creation_time_hour, creation_time_minute,
creation_time_second, 0, creation_time_offset);
DateTimeFormatter formatter = DateTimeFormatter.RFC_1123_DATE_TIME;
String encodedTime = offDateTime.format(formatter);
setEncodedTime(encodedTime);
}
}
private void setCreationTimeChunk(ListIterator<String> iter) {
// Check for iterator's valid state
if (iter != null && iter.hasNext()) {
tEXt_creation_time_iter = iter;
tEXt_creation_time_present = true;
}
}
private void setEncodedTime(String encodedTime) {
if (tEXt_creation_time_iter != null
&& tEXt_creation_time_iter.hasNext()
&& encodedTime != null) {
// Set the value at the iterator and reset its state
tEXt_creation_time_iter.next();
tEXt_creation_time_iter.set(encodedTime);
tEXt_creation_time_iter.previous();
}
}
private String getEncodedTime() {
String encodedTime = null;
if (tEXt_creation_time_iter != null
&& tEXt_creation_time_iter.hasNext()) {
// Get the value at iterator and reset its state
encodedTime = tEXt_creation_time_iter.next();
tEXt_creation_time_iter.previous();
}
return encodedTime;
}
private OffsetDateTime parseEncodedTime(String encodedTime) {
OffsetDateTime retVal = null;
boolean timeDecoded = false;
/*
* PNG specification recommends that image encoders use RFC1123 format
* to represent time in String but doesn't mandate. Encoders could
* use any convenient format. Hence, we extract time provided the
* encoded time complies with either RFC1123 or ISO standards.
*/
try {
// Check if the encoded time complies with RFC1123
retVal = OffsetDateTime.parse(encodedTime,
DateTimeFormatter.RFC_1123_DATE_TIME);
timeDecoded = true;
} catch (DateTimeParseException exception) {
// No Op. Encoded time did not comply with RFC1123 standard.
}
if (timeDecoded == false) {
try {
// Check if the encoded time complies with ISO standard.
DateTimeFormatter formatter = DateTimeFormatter.ISO_DATE_TIME;
TemporalAccessor dt = formatter.parseBest(encodedTime,
OffsetDateTime::from, LocalDateTime::from);
if (dt instanceof OffsetDateTime) {
// Encoded time contains date time and zone offset
retVal = (OffsetDateTime) dt;
} else if (dt instanceof LocalDateTime) {
/*
* Encoded time contains only date and time. Since zone
* offset information isn't available, we set to the default
*/
LocalDateTime locDT = (LocalDateTime) dt;
retVal = OffsetDateTime.of(locDT, ZoneOffset.UTC);
}
} catch (DateTimeParseException exception) {
// No Op. Encoded time did not comply with ISO standard.
}
}
return retVal;
}
boolean hasTransparentColor() {
return tRNS_present &&
(tRNS_colorType == PNGImageReader.PNG_COLOR_RGB ||
tRNS_colorType == PNGImageReader.PNG_COLOR_GRAY);
}
// Reset all instance variables to their initial state
public void reset() {
IHDR_present = false;
PLTE_present = false;
bKGD_present = false;
cHRM_present = false;
gAMA_present = false;
hIST_present = false;
iCCP_present = false;
iTXt_keyword = new ArrayList<String>();
iTXt_compressionFlag = new ArrayList<Boolean>();
iTXt_compressionMethod = new ArrayList<Integer>();
iTXt_languageTag = new ArrayList<String>();
iTXt_translatedKeyword = new ArrayList<String>();
iTXt_text = new ArrayList<String>();
pHYs_present = false;
sBIT_present = false;
sPLT_present = false;
sRGB_present = false;
tEXt_keyword = new ArrayList<String>();
tEXt_text = new ArrayList<String>();
// tIME chunk with Image modification time
tIME_present = false;
// Text chunk with Image creation time
tEXt_creation_time_present = false;
tEXt_creation_time_iter = null;
creation_time_present = false;
tRNS_present = false;
zTXt_keyword = new ArrayList<String>();
zTXt_compressionMethod = new ArrayList<Integer>();
zTXt_text = new ArrayList<String>();
unknownChunkType = new ArrayList<String>();
unknownChunkData = new ArrayList<byte[]>();
}
}