/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.imaging.formats.png;
import java.awt.Dimension;
import java.awt.color.ColorSpace;
import java.awt.color.ICC_ColorSpace;
import java.awt.color.ICC_Profile;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.zip.InflaterInputStream;
import org.apache.commons.imaging.ColorTools;
import org.apache.commons.imaging.ImageFormat;
import org.apache.commons.imaging.ImageFormats;
import org.apache.commons.imaging.ImageInfo;
import org.apache.commons.imaging.ImageParser;
import org.apache.commons.imaging.ImageReadException;
import org.apache.commons.imaging.ImageWriteException;
import org.apache.commons.imaging.common.IImageMetadata;
import org.apache.commons.imaging.common.ImageMetadata;
import org.apache.commons.imaging.common.bytesource.ByteSource;
import org.apache.commons.imaging.formats.png.chunks.PngChunk;
import org.apache.commons.imaging.formats.png.chunks.PngChunkGama;
import org.apache.commons.imaging.formats.png.chunks.PngChunkIccp;
import org.apache.commons.imaging.formats.png.chunks.PngChunkIdat;
import org.apache.commons.imaging.formats.png.chunks.PngChunkIhdr;
import org.apache.commons.imaging.formats.png.chunks.PngChunkItxt;
import org.apache.commons.imaging.formats.png.chunks.PngChunkPhys;
import org.apache.commons.imaging.formats.png.chunks.PngChunkPlte;
import org.apache.commons.imaging.formats.png.chunks.PngChunkText;
import org.apache.commons.imaging.formats.png.chunks.PngChunkZtxt;
import org.apache.commons.imaging.formats.png.chunks.PngTextChunk;
import org.apache.commons.imaging.formats.png.transparencyfilters.TransparencyFilter;
import org.apache.commons.imaging.formats.png.transparencyfilters.TransparencyFilterGrayscale;
import org.apache.commons.imaging.formats.png.transparencyfilters.TransparencyFilterIndexedColor;
import org.apache.commons.imaging.formats.png.transparencyfilters.TransparencyFilterTrueColor;
import org.apache.commons.imaging.icc.IccProfileParser;
import org.apache.commons.imaging.util.IoUtils;
import static org.apache.commons.imaging.ImagingConstants.*;
import static org.apache.commons.imaging.common.BinaryFunctions.*;
public class PngImageParser extends ImageParser {
private static final String DEFAULT_EXTENSION = ".png";
private static final String[] ACCEPTED_EXTENSIONS = { DEFAULT_EXTENSION, };
@Override
public String getName() {
return "Png-Custom";
}
@Override
public String getDefaultExtension() {
return DEFAULT_EXTENSION;
}
@Override
protected String[] getAcceptedExtensions() {
return ACCEPTED_EXTENSIONS;
}
@Override
protected ImageFormat[] getAcceptedTypes() {
return new ImageFormat[] { ImageFormats.PNG, //
};
}
// private final static int tRNS = CharsToQuad('t', 'R', 'N', 's');
public static String getChunkTypeName(final int chunkType) {
final StringBuilder result = new StringBuilder();
result.append((char) (0xff & (chunkType >> 24)));
result.append((char) (0xff & (chunkType >> 16)));
result.append((char) (0xff & (chunkType >> 8)));
result.append((char) (0xff & (chunkType >> 0)));
return result.toString();
}
/**
* @return List of String-formatted chunk types, ie. "tRNs".
*/
public List<String> getChuckTypes(final InputStream is)
throws ImageReadException, IOException {
final List<PngChunk> chunks = readChunks(is, null, false);
final List<String> chunkTypes = new ArrayList<String>();
for (PngChunk chunk : chunks) {
chunkTypes.add(getChunkTypeName(chunk.chunkType));
}
return chunkTypes;
}
public boolean hasChuckType(final ByteSource byteSource, final ChunkType chunkType)
throws ImageReadException, IOException {
InputStream is = null;
boolean canThrow = false;
try {
is = byteSource.getInputStream();
readSignature(is);
final List<PngChunk> chunks = readChunks(is, new ChunkType[] { chunkType }, true);
canThrow = true;
return !chunks.isEmpty();
} finally {
IoUtils.closeQuietly(canThrow, is);
}
}
private boolean keepChunk(final int chunkType, final ChunkType[] chunkTypes) {
// System.out.println("keepChunk: ");
if (chunkTypes == null) {
return true;
}
for (final ChunkType chunkType2 : chunkTypes) {
if (chunkType2.value == chunkType) {
return true;
}
}
return false;
}
private List<PngChunk> readChunks(final InputStream is, final ChunkType[] chunkTypes,
final boolean returnAfterFirst) throws ImageReadException, IOException {
final List<PngChunk> result = new ArrayList<PngChunk>();
while (true) {
if (getDebug()) {
System.out.println("");
}
final int length = read4Bytes("Length", is, "Not a Valid PNG File", getByteOrder());
final int chunkType = read4Bytes("ChunkType", is, "Not a Valid PNG File", getByteOrder());
if (getDebug()) {
printCharQuad("ChunkType", chunkType);
debugNumber("Length", length, 4);
}
final boolean keep = keepChunk(chunkType, chunkTypes);
byte[] bytes = null;
if (keep) {
bytes = readBytes("Chunk Data", is, length,
"Not a Valid PNG File: Couldn't read Chunk Data.");
} else {
skipBytes(is, length, "Not a Valid PNG File");
}
if (getDebug()) {
if (bytes != null) {
debugNumber("bytes", bytes.length, 4);
}
}
final int crc = read4Bytes("CRC", is, "Not a Valid PNG File", getByteOrder());
if (keep) {
if (chunkType == ChunkType.iCCP.value) {
result.add(new PngChunkIccp(length, chunkType, crc, bytes));
} else if (chunkType == ChunkType.tEXt.value) {
result.add(new PngChunkText(length, chunkType, crc, bytes));
} else if (chunkType == ChunkType.zTXt.value) {
result.add(new PngChunkZtxt(length, chunkType, crc, bytes));
} else if (chunkType == ChunkType.IHDR.value) {
result.add(new PngChunkIhdr(length, chunkType, crc, bytes));
} else if (chunkType == ChunkType.PLTE.value) {
result.add(new PngChunkPlte(length, chunkType, crc, bytes));
} else if (chunkType == ChunkType.pHYs.value) {
result.add(new PngChunkPhys(length, chunkType, crc, bytes));
} else if (chunkType == ChunkType.IDAT.value) {
result.add(new PngChunkIdat(length, chunkType, crc, bytes));
} else if (chunkType == ChunkType.gAMA.value) {
result.add(new PngChunkGama(length, chunkType, crc, bytes));
} else if (chunkType == ChunkType.iTXt.value) {
result.add(new PngChunkItxt(length, chunkType, crc, bytes));
} else {
result.add(new PngChunk(length, chunkType, crc, bytes));
}
if (returnAfterFirst) {
return result;
}
}
if (chunkType == ChunkType.IEND.value) {
break;
}
}
return result;
}
public void readSignature(final InputStream is) throws ImageReadException,
IOException {
readAndVerifyBytes(is, PngConstants.PNG_SIGNATURE,
"Not a Valid PNG Segment: Incorrect Signature");
}
private List<PngChunk> readChunks(final ByteSource byteSource, final ChunkType[] chunkTypes,
final boolean returnAfterFirst) throws ImageReadException, IOException {
InputStream is = null;
boolean canThrow = false;
try {
is = byteSource.getInputStream();
readSignature(is);
final List<PngChunk> ret = readChunks(is, chunkTypes, returnAfterFirst);
canThrow = true;
return ret;
} finally {
IoUtils.closeQuietly(canThrow, is);
}
}
@Override
public byte[] getICCProfileBytes(final ByteSource byteSource, final Map<String, Object> params)
throws ImageReadException, IOException {
final List<PngChunk> chunks = readChunks(byteSource, new ChunkType[] { ChunkType.iCCP },
true);
if ((chunks == null) || (chunks.isEmpty())) {
// throw new ImageReadException("Png: No chunks");
return null;
}
if (chunks.size() > 1) {
throw new ImageReadException(
"PNG contains more than one ICC Profile ");
}
final PngChunkIccp pngChunkiCCP = (PngChunkIccp) chunks.get(0);
final byte[] bytes = pngChunkiCCP.uncompressedProfile;
return (bytes);
}
@Override
public Dimension getImageSize(final ByteSource byteSource, final Map<String, Object> params)
throws ImageReadException, IOException {
final List<PngChunk> chunks = readChunks(byteSource, new ChunkType[] { ChunkType.IHDR, }, true);
if ((chunks == null) || (chunks.isEmpty())) {
throw new ImageReadException("Png: No chunks");
}
if (chunks.size() > 1) {
throw new ImageReadException("PNG contains more than one Header");
}
final PngChunkIhdr pngChunkIHDR = (PngChunkIhdr) chunks.get(0);
return new Dimension(pngChunkIHDR.width, pngChunkIHDR.height);
}
@Override
public IImageMetadata getMetadata(final ByteSource byteSource, final Map<String, Object> params)
throws ImageReadException, IOException {
final List<PngChunk> chunks = readChunks(byteSource, new ChunkType[] { ChunkType.tEXt, ChunkType.zTXt, }, true);
if ((chunks == null) || (chunks.isEmpty())) {
return null;
}
final ImageMetadata result = new ImageMetadata();
for (PngChunk chunk : chunks) {
final PngTextChunk textChunk = (PngTextChunk) chunk;
result.add(textChunk.getKeyword(), textChunk.getText());
}
return result;
}
private List<PngChunk> filterChunks(final List<PngChunk> chunks, final ChunkType type) {
final List<PngChunk> result = new ArrayList<PngChunk>();
for (PngChunk chunk : chunks) {
if (chunk.chunkType == type.value) {
result.add(chunk);
}
}
return result;
}
// TODO: I have been too casual about making inner classes subclass of
// BinaryFileParser
// I may not have always preserved byte order correctly.
private TransparencyFilter getTransparencyFilter(ColorType colorType, PngChunk pngChunktRNS)
throws ImageReadException, IOException {
switch (colorType) {
case GREYSCALE: // 1,2,4,8,16 Each pixel is a grayscale sample.
return new TransparencyFilterGrayscale(pngChunktRNS.getBytes());
case TRUE_COLOR: // 8,16 Each pixel is an R,G,B triple.
return new TransparencyFilterTrueColor(pngChunktRNS.getBytes());
case INDEXED_COLOR: // 1,2,4,8 Each pixel is a palette index;
return new TransparencyFilterIndexedColor(pngChunktRNS.getBytes());
case GREYSCALE_WITH_ALPHA: // 8,16 Each pixel is a grayscale sample,
case TRUE_COLOR_WITH_ALPHA: // 8,16 Each pixel is an R,G,B triple,
default:
throw new ImageReadException("Simple Transparency not compatible with ColorType: " + colorType);
}
}
@Override
public ImageInfo getImageInfo(final ByteSource byteSource, final Map<String, Object> params)
throws ImageReadException, IOException {
final List<PngChunk> chunks = readChunks(byteSource, new ChunkType[] {
ChunkType.IHDR,
ChunkType.pHYs,
ChunkType.tEXt,
ChunkType.zTXt,
ChunkType.tRNS,
ChunkType.PLTE,
ChunkType.iTXt,
}, false);
// if(chunks!=null)
// System.out.println("chunks: " + chunks.size());
if ((chunks == null) || (chunks.isEmpty())) {
throw new ImageReadException("PNG: no chunks");
}
final List<PngChunk> IHDRs = filterChunks(chunks, ChunkType.IHDR);
if (IHDRs.size() != 1) {
throw new ImageReadException("PNG contains more than one Header");
}
final PngChunkIhdr pngChunkIHDR = (PngChunkIhdr) IHDRs.get(0);
boolean transparent = false;
final List<PngChunk> tRNSs = filterChunks(chunks, ChunkType.tRNS);
if (!tRNSs.isEmpty()) {
transparent = true;
} else {
// CE - Fix Alpha.
transparent = pngChunkIHDR.colorType.hasAlpha();
// END FIX
}
PngChunkPhys pngChunkpHYs = null;
final List<PngChunk> pHYss = filterChunks(chunks, ChunkType.pHYs);
if (pHYss.size() > 1) {
throw new ImageReadException("PNG contains more than one pHYs: "
+ pHYss.size());
} else if (pHYss.size() == 1) {
pngChunkpHYs = (PngChunkPhys) pHYss.get(0);
}
final List<PngChunk> tEXts = filterChunks(chunks, ChunkType.tEXt);
final List<PngChunk> zTXts = filterChunks(chunks, ChunkType.zTXt);
final List<PngChunk> iTXts = filterChunks(chunks, ChunkType.iTXt);
final List<String> comments = new ArrayList<String>();
final List<PngText> textChunks = new ArrayList<PngText>();
for (PngChunk tEXt : tEXts) {
final PngChunkText pngChunktEXt = (PngChunkText) tEXt;
comments.add(pngChunktEXt.keyword + ": " + pngChunktEXt.text);
textChunks.add(pngChunktEXt.getContents());
}
for (PngChunk zTXt : zTXts) {
final PngChunkZtxt pngChunkzTXt = (PngChunkZtxt) zTXt;
comments.add(pngChunkzTXt.keyword + ": " + pngChunkzTXt.text);
textChunks.add(pngChunkzTXt.getContents());
}
for (PngChunk iTXt : iTXts) {
final PngChunkItxt pngChunkiTXt = (PngChunkItxt) iTXt;
comments.add(pngChunkiTXt.keyword + ": " + pngChunkiTXt.text);
textChunks.add(pngChunkiTXt.getContents());
}
final int bitsPerPixel = pngChunkIHDR.bitDepth * pngChunkIHDR.colorType.getSamplesPerPixel();
final ImageFormat format = ImageFormats.PNG;
final String formatName = "PNG Portable Network Graphics";
final int height = pngChunkIHDR.height;
final String mimeType = "image/png";
final int numberOfImages = 1;
final int width = pngChunkIHDR.width;
final boolean progressive = pngChunkIHDR.interlaceMethod.isProgressive();
int physicalHeightDpi = -1;
float physicalHeightInch = -1;
int physicalWidthDpi = -1;
float physicalWidthInch = -1;
// if (pngChunkpHYs != null)
// {
// System.out.println("\t" + "pngChunkpHYs.UnitSpecifier: " +
// pngChunkpHYs.UnitSpecifier );
// System.out.println("\t" + "pngChunkpHYs.PixelsPerUnitYAxis: " +
// pngChunkpHYs.PixelsPerUnitYAxis );
// System.out.println("\t" + "pngChunkpHYs.PixelsPerUnitXAxis: " +
// pngChunkpHYs.PixelsPerUnitXAxis );
// }
if ((pngChunkpHYs != null) && (pngChunkpHYs.unitSpecifier == 1)) { // meters
final double metersPerInch = 0.0254;
physicalWidthDpi = (int) Math.round(pngChunkpHYs.pixelsPerUnitXAxis * metersPerInch);
physicalWidthInch = (float) (width / (pngChunkpHYs.pixelsPerUnitXAxis * metersPerInch));
physicalHeightDpi = (int) Math.round(pngChunkpHYs.pixelsPerUnitYAxis * metersPerInch);
physicalHeightInch = (float) (height / (pngChunkpHYs.pixelsPerUnitYAxis * metersPerInch));
}
final String formatDetails = "Png";
boolean usesPalette = false;
final List<PngChunk> PLTEs = filterChunks(chunks, ChunkType.PLTE);
if (PLTEs.size() > 1) {
usesPalette = true;
}
int colorType;
switch (pngChunkIHDR.colorType) {
case GREYSCALE:
case GREYSCALE_WITH_ALPHA:
colorType = ImageInfo.COLOR_TYPE_GRAYSCALE;
break;
case TRUE_COLOR:
case INDEXED_COLOR:
case TRUE_COLOR_WITH_ALPHA:
colorType = ImageInfo.COLOR_TYPE_RGB;
break;
default:
throw new ImageReadException("Png: Unknown ColorType: " + pngChunkIHDR.colorType);
}
final String compressionAlgorithm = ImageInfo.COMPRESSION_ALGORITHM_PNG_FILTER;
return new PngImageInfo(formatDetails, bitsPerPixel, comments,
format, formatName, height, mimeType, numberOfImages,
physicalHeightDpi, physicalHeightInch, physicalWidthDpi,
physicalWidthInch, width, progressive, transparent,
usesPalette, colorType, compressionAlgorithm, textChunks);
}
@Override
public BufferedImage getBufferedImage(final ByteSource byteSource, final Map<String, Object> params)
throws ImageReadException, IOException {
if (params.containsKey(PARAM_KEY_VERBOSE)) {
params.remove(PARAM_KEY_VERBOSE);
}
// if (params.size() > 0) {
// Object firstKey = params.keySet().iterator().next();
// throw new ImageWriteException("Unknown parameter: " + firstKey);
// }
final List<PngChunk> chunks = readChunks(byteSource, new ChunkType[] {
ChunkType.IHDR,
ChunkType.PLTE,
ChunkType.IDAT,
ChunkType.tRNS,
ChunkType.iCCP,
ChunkType.gAMA,
ChunkType.sRGB,
}, false);
if ((chunks == null) || (chunks.isEmpty())) {
throw new ImageReadException("PNG: no chunks");
}
final List<PngChunk> IHDRs = filterChunks(chunks, ChunkType.IHDR);
if (IHDRs.size() != 1) {
throw new ImageReadException("PNG contains more than one Header");
}
final PngChunkIhdr pngChunkIHDR = (PngChunkIhdr) IHDRs.get(0);
final List<PngChunk> PLTEs = filterChunks(chunks, ChunkType.PLTE);
if (PLTEs.size() > 1) {
throw new ImageReadException("PNG contains more than one Palette");
}
PngChunkPlte pngChunkPLTE = null;
if (PLTEs.size() == 1) {
pngChunkPLTE = (PngChunkPlte) PLTEs.get(0);
}
// -----
final List<PngChunk> IDATs = filterChunks(chunks, ChunkType.IDAT);
if (IDATs.isEmpty()) {
throw new ImageReadException("PNG missing image data");
}
ByteArrayOutputStream baos = new ByteArrayOutputStream();
for (PngChunk IDAT : IDATs) {
final PngChunkIdat pngChunkIDAT = (PngChunkIdat) IDAT;
final byte[] bytes = pngChunkIDAT.getBytes();
// System.out.println(i + ": bytes: " + bytes.length);
baos.write(bytes);
}
final byte[] compressed = baos.toByteArray();
baos = null;
TransparencyFilter transparencyFilter = null;
final List<PngChunk> tRNSs = filterChunks(chunks, ChunkType.tRNS);
if (!tRNSs.isEmpty()) {
final PngChunk pngChunktRNS = tRNSs.get(0);
transparencyFilter = getTransparencyFilter(pngChunkIHDR.colorType, pngChunktRNS);
}
ICC_Profile iccProfile = null;
GammaCorrection gammaCorrection = null;
{
final List<PngChunk> sRGBs = filterChunks(chunks, ChunkType.sRGB);
final List<PngChunk> gAMAs = filterChunks(chunks, ChunkType.gAMA);
final List<PngChunk> iCCPs = filterChunks(chunks, ChunkType.iCCP);
if (sRGBs.size() > 1) {
throw new ImageReadException("PNG: unexpected sRGB chunk");
}
if (gAMAs.size() > 1) {
throw new ImageReadException("PNG: unexpected gAMA chunk");
}
if (iCCPs.size() > 1) {
throw new ImageReadException("PNG: unexpected iCCP chunk");
}
if (sRGBs.size() == 1) {
// no color management neccesary.
if (getDebug()) {
System.out.println("sRGB, no color management neccesary.");
}
} else if (iCCPs.size() == 1) {
if (getDebug()) {
System.out.println("iCCP.");
}
final PngChunkIccp pngChunkiCCP = (PngChunkIccp) iCCPs.get(0);
final byte[] bytes = pngChunkiCCP.uncompressedProfile;
iccProfile = ICC_Profile.getInstance(bytes);
} else if (gAMAs.size() == 1) {
final PngChunkGama pngChunkgAMA = (PngChunkGama) gAMAs.get(0);
final double gamma = pngChunkgAMA.getGamma();
// charles: what is the correct target value here?
// double targetGamma = 2.2;
final double targetGamma = 1.0;
final double diff = Math.abs(targetGamma - gamma);
if (diff >= 0.5) {
gammaCorrection = new GammaCorrection(gamma, targetGamma);
}
if (gammaCorrection != null) {
if (pngChunkPLTE != null) {
pngChunkPLTE.correct(gammaCorrection);
}
}
}
}
{
final int width = pngChunkIHDR.width;
final int height = pngChunkIHDR.height;
final ColorType colorType = pngChunkIHDR.colorType;
final int bitDepth = pngChunkIHDR.bitDepth;
if (pngChunkIHDR.filterMethod != 0) {
throw new ImageReadException("PNG: unknown FilterMethod: " + pngChunkIHDR.filterMethod);
}
final int bitsPerPixel = bitDepth * colorType.getSamplesPerPixel();
final boolean hasAlpha = colorType.hasAlpha() || transparencyFilter != null;
BufferedImage result;
if (colorType.isGreyscale()) {
result = getBufferedImageFactory(params).getGrayscaleBufferedImage(width, height, hasAlpha);
} else {
result = getBufferedImageFactory(params).getColorBufferedImage(width, height, hasAlpha);
}
final ByteArrayInputStream bais = new ByteArrayInputStream(compressed);
final InflaterInputStream iis = new InflaterInputStream(bais);
ScanExpediter scanExpediter;
switch (pngChunkIHDR.interlaceMethod) {
case NONE:
scanExpediter = new ScanExpediterSimple(width, height, iis,
result, colorType, bitDepth, bitsPerPixel,
pngChunkPLTE, gammaCorrection, transparencyFilter);
break;
case ADAM7:
scanExpediter = new ScanExpediterInterlaced(width, height, iis,
result, colorType, bitDepth, bitsPerPixel,
pngChunkPLTE, gammaCorrection, transparencyFilter);
break;
default:
throw new ImageReadException("Unknown InterlaceMethod: " + pngChunkIHDR.interlaceMethod);
}
scanExpediter.drive();
if (iccProfile != null) {
final Boolean is_srgb = new IccProfileParser().issRGB(iccProfile);
if (is_srgb == null || !is_srgb.booleanValue()) {
final ICC_ColorSpace cs = new ICC_ColorSpace(iccProfile);
final ColorModel srgbCM = ColorModel.getRGBdefault();
final ColorSpace cs_sRGB = srgbCM.getColorSpace();
result = new ColorTools().convertBetweenColorSpaces(result, cs, cs_sRGB);
}
}
return result;
}
}
@Override
public boolean dumpImageFile(final PrintWriter pw, final ByteSource byteSource)
throws ImageReadException, IOException {
final ImageInfo imageInfo = getImageInfo(byteSource);
if (imageInfo == null) {
return false;
}
imageInfo.toString(pw, "");
final List<PngChunk> chunks = readChunks(byteSource, null, false);
final List<PngChunk> IHDRs = filterChunks(chunks, ChunkType.IHDR);
if (IHDRs.size() != 1) {
if (getDebug()) {
System.out.println("PNG contains more than one Header");
}
return false;
}
final PngChunkIhdr pngChunkIHDR = (PngChunkIhdr) IHDRs.get(0);
pw.println("Color: " + pngChunkIHDR.colorType.name());
pw.println("chunks: " + chunks.size());
if ((chunks.isEmpty())) {
return false;
}
for (int i = 0; i < chunks.size(); i++) {
final PngChunk chunk = chunks.get(i);
printCharQuad(pw, "\t" + i + ": ", chunk.chunkType);
}
pw.println("");
pw.flush();
return true;
}
@Override
public void writeImage(final BufferedImage src, final OutputStream os, final Map<String, Object> params)
throws ImageWriteException, IOException {
new PngWriter(params).writeImage(src, os, params);
}
@Override
public String getXmpXml(final ByteSource byteSource, final Map<String, Object> params)
throws ImageReadException, IOException {
final List<PngChunk> chunks = readChunks(byteSource, new ChunkType[] { ChunkType.iTXt }, false);
if ((chunks == null) || (chunks.isEmpty())) {
return null;
}
final List<PngChunkItxt> xmpChunks = new ArrayList<PngChunkItxt>();
for (PngChunk chunk : chunks) {
final PngChunkItxt itxtChunk = (PngChunkItxt) chunk;
if (!itxtChunk.getKeyword().equals(PngConstants.XMP_KEYWORD)) {
continue;
}
xmpChunks.add(itxtChunk);
}
if (xmpChunks.isEmpty()) {
return null;
}
if (xmpChunks.size() > 1) {
throw new ImageReadException(
"PNG contains more than one XMP chunk.");
}
final PngChunkItxt chunk = xmpChunks.get(0);
return chunk.getText();
}
}