org.apache.xmlgraphics.image.codec.png.PNGImageDecoder Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of xmlgraphics-commons Show documentation
Show all versions of xmlgraphics-commons Show documentation
Apache XML Graphics Commons is a library that consists of several reusable
components used by Apache Batik and Apache FOP. Many of these components
can easily be used separately outside the domains of SVG and XSL-FO.
/*
* 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.
*/
/* $Id: PNGImageDecoder.java 1732018 2016-02-24 04:51:06Z gadams $ */
package org.apache.xmlgraphics.image.codec.png;
import java.awt.Color;
import java.awt.Point;
import java.awt.Transparency;
import java.awt.color.ColorSpace;
import java.awt.image.ColorModel;
import java.awt.image.ComponentColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;
import java.awt.image.DataBufferUShort;
import java.awt.image.IndexColorModel;
import java.awt.image.Raster;
import java.awt.image.RenderedImage;
import java.awt.image.SampleModel;
import java.awt.image.WritableRaster;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.SequenceInputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.List;
import java.util.Locale;
import java.util.TimeZone;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;
import javax.imageio.stream.ImageInputStream;
import org.apache.xmlgraphics.image.codec.util.ImageDecoderImpl;
import org.apache.xmlgraphics.image.codec.util.ImageInputStreamSeekableStreamAdapter;
import org.apache.xmlgraphics.image.codec.util.PropertyUtil;
import org.apache.xmlgraphics.image.codec.util.SeekableStream;
import org.apache.xmlgraphics.image.codec.util.SimpleRenderedImage;
import org.apache.xmlgraphics.image.loader.ImageSize;
import org.apache.xmlgraphics.image.loader.impl.PNGConstants;
// CSOFF: ConstantName
// CSOFF: InnerAssignment
// CSOFF: MethodName
// CSOFF: MissingSwitchDefault
// CSOFF: MultipleVariableDeclarations
// CSOFF: NoWhitespaceAfter
// CSOFF: OperatorWrap
// CSOFF: WhitespaceAround
/**
* @version $Id: PNGImageDecoder.java 1732018 2016-02-24 04:51:06Z gadams $
*/
public class PNGImageDecoder extends ImageDecoderImpl {
public PNGImageDecoder(InputStream input,
PNGDecodeParam param) {
super(input, param);
}
@Override
public RenderedImage decodeAsRenderedImage(int page) throws IOException {
if (page != 0) {
throw new IOException(PropertyUtil.getString("PNGImageDecoder19"));
}
return new PNGImage(input, (PNGDecodeParam)param);
}
public static void readPNGHeader(ImageInputStream inputStream, ImageSize size) throws IOException {
SeekableStream seekStream = new ImageInputStreamSeekableStreamAdapter(inputStream) {
public void close() throws IOException {
}
};
PNGImage pngImage = new PNGImage(seekStream);
size.setSizeInPixels(pngImage.getWidth(), pngImage.getHeight());
double dpiHorz = size.getDpiHorizontal();
double dpiVert = size.getDpiVertical();
if (pngImage.unitSpecifier == 1) {
if (pngImage.xPixelsPerUnit != 0) {
dpiHorz = pngImage.xPixelsPerUnit * 0.0254;
}
if (pngImage.yPixelsPerUnit != 0) {
dpiVert = pngImage.yPixelsPerUnit * 0.0254;
}
}
size.setResolution(dpiHorz, dpiVert);
size.calcSizeFromPixels();
}
}
/**
* TO DO:
*
* zTXt chunks
*
*/
class PNGImage extends SimpleRenderedImage implements PNGConstants {
private static final String[] colorTypeNames = {
"Grayscale", "Error", "Truecolor", "Index",
"Grayscale with alpha", "Error", "Truecolor with alpha"
};
private int[][] bandOffsets = {
null,
{ 0 }, // G
{ 0, 1 }, // GA in GA order
{ 0, 1, 2 }, // RGB in RGB order
{ 0, 1, 2, 3 } // RGBA in RGBA order
};
private int bitDepth;
private int colorType;
private int compressionMethod;
private int filterMethod;
private int interlaceMethod;
private int paletteEntries;
private byte[] redPalette;
private byte[] greenPalette;
private byte[] bluePalette;
private byte[] alphaPalette;
private int bkgdRed;
private int bkgdGreen;
private int bkgdBlue;
private int grayTransparentAlpha;
private int redTransparentAlpha;
private int greenTransparentAlpha;
private int blueTransparentAlpha;
private int maxOpacity;
private int[] significantBits;
// Parameter information
// If true, the user wants destination alpha where applicable.
private boolean suppressAlpha;
// If true, perform palette lookup internally
private boolean expandPalette;
// If true, output < 8 bit gray images in 8 bit components format
private boolean output8BitGray;
// Create an alpha channel in the destination color model.
private boolean outputHasAlphaPalette;
// Perform gamma correction on the image
private boolean performGammaCorrection;
// Expand GA to GGGA for compatbility with Java2D
private boolean expandGrayAlpha;
// Produce an instance of PNGEncodeParam
private boolean generateEncodeParam;
// PNGDecodeParam controlling decode process
private PNGDecodeParam decodeParam;
// PNGEncodeParam to store file details in
private PNGEncodeParam encodeParam;
private boolean emitProperties = true;
private float fileGamma = 45455 / 100000.0F;
private float userExponent = 1.0F;
private float displayExponent = 2.2F;
private float[] chromaticity;
private int sRGBRenderingIntent = -1;
// Post-processing step implied by above parameters
private int postProcess = POST_NONE;
protected int xPixelsPerUnit;
protected int yPixelsPerUnit;
protected int unitSpecifier;
// Possible post-processing steps
// Do nothing
private static final int POST_NONE = 0;
// Gamma correct only
private static final int POST_GAMMA = 1;
// Push gray values through grayLut to expand to 8 bits
private static final int POST_GRAY_LUT = 2;
// Push gray values through grayLut to expand to 8 bits, add alpha
private static final int POST_GRAY_LUT_ADD_TRANS = 3;
// Push palette value through R,G,B lookup tables
private static final int POST_PALETTE_TO_RGB = 4;
// Push palette value through R,G,B,A lookup tables
private static final int POST_PALETTE_TO_RGBA = 5;
// Add transparency to a given gray value (w/ optional gamma)
private static final int POST_ADD_GRAY_TRANS = 6;
// Add transparency to a given RGB value (w/ optional gamma)
private static final int POST_ADD_RGB_TRANS = 7;
// Remove the alpha channel from a gray image (w/ optional gamma)
private static final int POST_REMOVE_GRAY_TRANS = 8;
// Remove the alpha channel from an RGB image (w/optional gamma)
private static final int POST_REMOVE_RGB_TRANS = 9;
// Mask to add expansion of GA -> GGGA
private static final int POST_EXP_MASK = 16;
// Expand gray to G/G/G
private static final int POST_GRAY_ALPHA_EXP =
POST_NONE | POST_EXP_MASK;
// Expand gray to G/G/G through a gamma lut
private static final int POST_GAMMA_EXP =
POST_GAMMA | POST_EXP_MASK;
// Push gray values through grayLut to expand to 8 bits, expand, add alpha
private static final int POST_GRAY_LUT_ADD_TRANS_EXP =
POST_GRAY_LUT_ADD_TRANS | POST_EXP_MASK;
// Add transparency to a given gray value, expand
private static final int POST_ADD_GRAY_TRANS_EXP =
POST_ADD_GRAY_TRANS | POST_EXP_MASK;
private List streamVec = new ArrayList();
private DataInputStream dataStream;
private int bytesPerPixel; // number of bytes per input pixel
private int inputBands;
private int outputBands;
// Number of private chunks
private int chunkIndex;
private List textKeys = new ArrayList();
private List textStrings = new ArrayList();
private List ztextKeys = new ArrayList();
private List ztextStrings = new ArrayList();
private WritableRaster theTile;
private int[] gammaLut;
private void initGammaLut(int bits) {
double exp = (double)userExponent / (fileGamma * displayExponent);
int numSamples = 1 << bits;
int maxOutSample = (bits == 16) ? 65535 : 255;
gammaLut = new int[numSamples];
for (int i = 0; i < numSamples; i++) {
double gbright = (double)i / (numSamples - 1);
double gamma = Math.pow(gbright, exp);
int igamma = (int)(gamma * maxOutSample + 0.5);
if (igamma > maxOutSample) {
igamma = maxOutSample;
}
gammaLut[i] = igamma;
}
}
private final byte[][] expandBits = {
null,
{ (byte)0x00, (byte)0xff },
{ (byte)0x00, (byte)0x55, (byte)0xaa, (byte)0xff },
null,
{ (byte)0x00, (byte)0x11, (byte)0x22, (byte)0x33,
(byte)0x44, (byte)0x55, (byte)0x66, (byte)0x77,
(byte)0x88, (byte)0x99, (byte)0xaa, (byte)0xbb,
(byte)0xcc, (byte)0xdd, (byte)0xee, (byte)0xff }
};
private int[] grayLut;
private void initGrayLut(int bits) {
int len = 1 << bits;
grayLut = new int[len];
if (performGammaCorrection) {
System.arraycopy(gammaLut, 0, grayLut, 0, len);
} else {
for (int i = 0; i < len; i++) {
grayLut[i] = expandBits[bits][i];
}
}
}
public PNGImage(InputStream stream) throws IOException {
DataInputStream distream = new DataInputStream(stream);
long magic = distream.readLong();
if (magic != PNG_SIGNATURE) {
throw new IOException("Not a png file");
}
while (true) {
String chunkType = PNGChunk.getChunkType(distream);
if (chunkType.equals(PNGChunk.ChunkType.IHDR.name())) {
PNGChunk chunk = PNGChunk.readChunk(distream);
parse_IHDR_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.pHYs.name())) {
PNGChunk chunk = PNGChunk.readChunk(distream);
parse_pHYs_chunk(chunk);
return;
} else if (chunkType.equals(PNGChunk.ChunkType.IEND.name())) {
return;
} else {
PNGChunk.readChunk(distream);
}
}
}
public PNGImage(InputStream stream, PNGDecodeParam decodeParam)
throws IOException {
if (!stream.markSupported()) {
stream = new BufferedInputStream(stream);
}
DataInputStream distream = new DataInputStream(stream);
if (decodeParam == null) {
decodeParam = new PNGDecodeParam();
}
this.decodeParam = decodeParam;
// Get parameter values
this.suppressAlpha = decodeParam.getSuppressAlpha();
this.expandPalette = decodeParam.getExpandPalette();
this.output8BitGray = decodeParam.getOutput8BitGray();
this.expandGrayAlpha = decodeParam.getExpandGrayAlpha();
if (decodeParam.getPerformGammaCorrection()) {
this.userExponent = decodeParam.getUserExponent();
this.displayExponent = decodeParam.getDisplayExponent();
performGammaCorrection = true;
output8BitGray = true;
}
this.generateEncodeParam = decodeParam.getGenerateEncodeParam();
if (emitProperties) {
properties.put("file_type", "PNG v. 1.0");
}
try {
long magic = distream.readLong();
if (magic != PNG_SIGNATURE) {
String msg = PropertyUtil.getString("PNGImageDecoder0");
throw new RuntimeException(msg);
}
} catch (IOException ioe) {
ioe.printStackTrace();
String msg = PropertyUtil.getString("PNGImageDecoder1");
throw new RuntimeException(msg);
}
do {
// try {
PNGChunk chunk;
String chunkType = PNGChunk.getChunkType(distream);
if (chunkType.equals(PNGChunk.ChunkType.IHDR.name())) {
chunk = PNGChunk.readChunk(distream);
parse_IHDR_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.PLTE.name())) {
chunk = PNGChunk.readChunk(distream);
parse_PLTE_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.IDAT.name())) {
chunk = PNGChunk.readChunk(distream);
streamVec.add(new ByteArrayInputStream(chunk.getData()));
} else if (chunkType.equals(PNGChunk.ChunkType.IEND.name())) {
chunk = PNGChunk.readChunk(distream);
try {
parse_IEND_chunk(chunk);
} catch (Exception e) {
e.printStackTrace();
String msg = PropertyUtil.getString("PNGImageDecoder2");
throw new RuntimeException(msg);
}
break; // fall through to the bottom
} else if (chunkType.equals(PNGChunk.ChunkType.bKGD.name())) {
chunk = PNGChunk.readChunk(distream);
parse_bKGD_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.cHRM.name())) {
chunk = PNGChunk.readChunk(distream);
parse_cHRM_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.gAMA.name())) {
chunk = PNGChunk.readChunk(distream);
parse_gAMA_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.hIST.name())) {
chunk = PNGChunk.readChunk(distream);
parse_hIST_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.iCCP.name())) {
chunk = PNGChunk.readChunk(distream);
parse_iCCP_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.pHYs.name())) {
chunk = PNGChunk.readChunk(distream);
parse_pHYs_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.sBIT.name())) {
chunk = PNGChunk.readChunk(distream);
parse_sBIT_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.sRGB.name())) {
chunk = PNGChunk.readChunk(distream);
parse_sRGB_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.tEXt.name())) {
chunk = PNGChunk.readChunk(distream);
parse_tEXt_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.tIME.name())) {
chunk = PNGChunk.readChunk(distream);
parse_tIME_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.tRNS.name())) {
chunk = PNGChunk.readChunk(distream);
parse_tRNS_chunk(chunk);
} else if (chunkType.equals(PNGChunk.ChunkType.zTXt.name())) {
chunk = PNGChunk.readChunk(distream);
parse_zTXt_chunk(chunk);
} else {
chunk = PNGChunk.readChunk(distream);
// Output the chunk data in raw form
String type = chunk.getTypeString();
byte[] data = chunk.getData();
if (encodeParam != null) {
encodeParam.addPrivateChunk(type, data);
}
if (emitProperties) {
String key = "chunk_" + chunkIndex++ + ':' + type;
properties.put(key.toLowerCase(Locale.getDefault()), data);
}
}
// } catch (Exception e) {
// e.printStackTrace();
// String msg = PropertyUtil.getString("PNGImageDecoder2");
// throw new RuntimeException(msg);
// }
} while (true);
// Final post-processing
if (significantBits == null) {
significantBits = new int[inputBands];
for (int i = 0; i < inputBands; i++) {
significantBits[i] = bitDepth;
}
if (emitProperties) {
properties.put("significant_bits", significantBits);
}
}
}
private void parse_IHDR_chunk(PNGChunk chunk) {
tileWidth = width = chunk.getInt4(0);
tileHeight = height = chunk.getInt4(4);
bitDepth = chunk.getInt1(8);
if ((bitDepth != 1) && (bitDepth != 2) && (bitDepth != 4)
&& (bitDepth != 8) && (bitDepth != 16)) {
// Error -- bad bit depth
String msg = PropertyUtil.getString("PNGImageDecoder3");
throw new RuntimeException(msg);
}
maxOpacity = (1 << bitDepth) - 1;
colorType = chunk.getInt1(9);
if ((colorType != PNG_COLOR_GRAY)
&& (colorType != PNG_COLOR_RGB)
&& (colorType != PNG_COLOR_PALETTE)
&& (colorType != PNG_COLOR_GRAY_ALPHA)
&& (colorType != PNG_COLOR_RGB_ALPHA)) {
System.out.println(PropertyUtil.getString("PNGImageDecoder4"));
}
if ((colorType == PNG_COLOR_RGB) && (bitDepth < 8)) {
// Error -- RGB images must have 8 or 16 bits
String msg = PropertyUtil.getString("PNGImageDecoder5");
throw new RuntimeException(msg);
}
if ((colorType == PNG_COLOR_PALETTE) && (bitDepth == 16)) {
// Error -- palette images must have < 16 bits
String msg = PropertyUtil.getString("PNGImageDecoder6");
throw new RuntimeException(msg);
}
if ((colorType == PNG_COLOR_GRAY_ALPHA) && (bitDepth < 8)) {
// Error -- gray/alpha images must have >= 8 bits
String msg = PropertyUtil.getString("PNGImageDecoder7");
throw new RuntimeException(msg);
}
if ((colorType == PNG_COLOR_RGB_ALPHA) && (bitDepth < 8)) {
// Error -- RGB/alpha images must have >= 8 bits
String msg = PropertyUtil.getString("PNGImageDecoder8");
throw new RuntimeException(msg);
}
if (emitProperties) {
properties.put("color_type", colorTypeNames[colorType]);
}
if (generateEncodeParam) {
if (colorType == PNG_COLOR_PALETTE) {
encodeParam = new PNGEncodeParam.Palette();
} else if (colorType == PNG_COLOR_GRAY
|| colorType == PNG_COLOR_GRAY_ALPHA) {
encodeParam = new PNGEncodeParam.Gray();
} else {
encodeParam = new PNGEncodeParam.RGB();
}
decodeParam.setEncodeParam(encodeParam);
}
if (encodeParam != null) {
encodeParam.setBitDepth(bitDepth);
}
if (emitProperties) {
properties.put("bit_depth", bitDepth);
}
if (performGammaCorrection) {
// Assume file gamma is 1/2.2 unless we get a gAMA chunk
float gamma = (1.0F / 2.2F) * (displayExponent / userExponent);
if (encodeParam != null) {
encodeParam.setGamma(gamma);
}
if (emitProperties) {
properties.put("gamma", gamma);
}
}
compressionMethod = chunk.getInt1(10);
if (compressionMethod != 0) {
// Error -- only know about compression method 0
String msg = PropertyUtil.getString("PNGImageDecoder9");
throw new RuntimeException(msg);
}
filterMethod = chunk.getInt1(11);
if (filterMethod != 0) {
// Error -- only know about filter method 0
String msg = PropertyUtil.getString("PNGImageDecoder10");
throw new RuntimeException(msg);
}
interlaceMethod = chunk.getInt1(12);
if (interlaceMethod == 0) {
if (encodeParam != null) {
encodeParam.setInterlacing(false);
}
if (emitProperties) {
properties.put("interlace_method", "None");
}
} else if (interlaceMethod == 1) {
if (encodeParam != null) {
encodeParam.setInterlacing(true);
}
if (emitProperties) {
properties.put("interlace_method", "Adam7");
}
} else {
// Error -- only know about Adam7 interlacing
String msg = PropertyUtil.getString("PNGImageDecoder11");
throw new RuntimeException(msg);
}
bytesPerPixel = (bitDepth == 16) ? 2 : 1;
switch (colorType) {
case PNG_COLOR_GRAY:
inputBands = 1;
outputBands = 1;
if (output8BitGray && (bitDepth < 8)) {
postProcess = POST_GRAY_LUT;
} else if (performGammaCorrection) {
postProcess = POST_GAMMA;
} else {
postProcess = POST_NONE;
}
break;
case PNG_COLOR_RGB:
inputBands = 3;
bytesPerPixel *= 3;
outputBands = 3;
if (performGammaCorrection) {
postProcess = POST_GAMMA;
} else {
postProcess = POST_NONE;
}
break;
case PNG_COLOR_PALETTE:
inputBands = 1;
bytesPerPixel = 1;
outputBands = expandPalette ? 3 : 1;
if (expandPalette) {
postProcess = POST_PALETTE_TO_RGB;
} else {
postProcess = POST_NONE;
}
break;
case PNG_COLOR_GRAY_ALPHA:
inputBands = 2;
bytesPerPixel *= 2;
if (suppressAlpha) {
outputBands = 1;
postProcess = POST_REMOVE_GRAY_TRANS;
} else {
if (performGammaCorrection) {
postProcess = POST_GAMMA;
} else {
postProcess = POST_NONE;
}
if (expandGrayAlpha) {
postProcess |= POST_EXP_MASK;
outputBands = 4;
} else {
outputBands = 2;
}
}
break;
case PNG_COLOR_RGB_ALPHA:
inputBands = 4;
bytesPerPixel *= 4;
outputBands = (!suppressAlpha) ? 4 : 3;
if (suppressAlpha) {
postProcess = POST_REMOVE_RGB_TRANS;
} else if (performGammaCorrection) {
postProcess = POST_GAMMA;
} else {
postProcess = POST_NONE;
}
break;
}
}
private void parse_IEND_chunk(PNGChunk chunk) throws Exception {
// Store text strings
int textLen = textKeys.size();
String[] textArray = new String[2 * textLen];
for (int i = 0; i < textLen; i++) {
String key = (String)textKeys.get(i);
String val = (String)textStrings.get(i);
textArray[2 * i] = key;
textArray[2 * i + 1] = val;
if (emitProperties) {
String uniqueKey = "text_" + i + ':' + key;
properties.put(uniqueKey.toLowerCase(Locale.getDefault()), val);
}
}
if (encodeParam != null) {
encodeParam.setText(textArray);
}
// Store compressed text strings
int ztextLen = ztextKeys.size();
String[] ztextArray = new String[2 * ztextLen];
for (int i = 0; i < ztextLen; i++) {
String key = (String)ztextKeys.get(i);
String val = (String)ztextStrings.get(i);
ztextArray[2 * i] = key;
ztextArray[2 * i + 1] = val;
if (emitProperties) {
String uniqueKey = "ztext_" + i + ':' + key;
properties.put(uniqueKey.toLowerCase(Locale.getDefault()), val);
}
}
if (encodeParam != null) {
encodeParam.setCompressedText(ztextArray);
}
// Parse prior IDAT chunks
InputStream seqStream =
new SequenceInputStream(Collections.enumeration(streamVec));
InputStream infStream =
new InflaterInputStream(seqStream, new Inflater());
dataStream = new DataInputStream(infStream);
// Create an empty WritableRaster
int depth = bitDepth;
if ((colorType == PNG_COLOR_GRAY)
&& (bitDepth < 8) && output8BitGray) {
depth = 8;
}
if ((colorType == PNG_COLOR_PALETTE) && expandPalette) {
depth = 8;
}
int bytesPerRow = (outputBands * width * depth + 7) / 8;
int scanlineStride =
(depth == 16) ? (bytesPerRow / 2) : bytesPerRow;
theTile = createRaster(width, height, outputBands,
scanlineStride,
depth);
if (performGammaCorrection && (gammaLut == null)) {
initGammaLut(bitDepth);
}
if ((postProcess == POST_GRAY_LUT)
|| (postProcess == POST_GRAY_LUT_ADD_TRANS)
|| (postProcess == POST_GRAY_LUT_ADD_TRANS_EXP)) {
initGrayLut(bitDepth);
}
decodeImage(interlaceMethod == 1);
sampleModel = theTile.getSampleModel();
if ((colorType == PNG_COLOR_PALETTE) && !expandPalette) {
if (outputHasAlphaPalette) {
colorModel = new IndexColorModel(bitDepth,
paletteEntries,
redPalette,
greenPalette,
bluePalette,
alphaPalette);
} else {
colorModel = new IndexColorModel(bitDepth,
paletteEntries,
redPalette,
greenPalette,
bluePalette);
}
} else if ((colorType == PNG_COLOR_GRAY)
&& (bitDepth < 8) && !output8BitGray) {
byte[] palette = expandBits[bitDepth];
colorModel = new IndexColorModel(bitDepth,
palette.length,
palette,
palette,
palette);
} else {
colorModel =
createComponentColorModel(sampleModel);
}
}
private static final int[] GrayBits8 = { 8 };
private static final ComponentColorModel colorModelGray8 =
new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_GRAY),
GrayBits8, false, false,
Transparency.OPAQUE,
DataBuffer.TYPE_BYTE);
private static final int[] GrayAlphaBits8 = { 8, 8 };
private static final ComponentColorModel colorModelGrayAlpha8 =
new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_GRAY),
GrayAlphaBits8, true, false,
Transparency.TRANSLUCENT,
DataBuffer.TYPE_BYTE);
private static final int[] GrayBits16 = { 16 };
private static final ComponentColorModel colorModelGray16 =
new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_GRAY),
GrayBits16, false, false,
Transparency.OPAQUE,
DataBuffer.TYPE_USHORT);
private static final int[] GrayAlphaBits16 = { 16, 16 };
private static final ComponentColorModel colorModelGrayAlpha16 =
new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_GRAY),
GrayAlphaBits16, true, false,
Transparency.TRANSLUCENT,
DataBuffer.TYPE_USHORT);
private static final int[] GrayBits32 = { 32 };
private static final ComponentColorModel colorModelGray32 =
new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_GRAY),
GrayBits32, false, false,
Transparency.OPAQUE,
DataBuffer.TYPE_INT);
private static final int[] GrayAlphaBits32 = { 32, 32 };
private static final ComponentColorModel colorModelGrayAlpha32 =
new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_GRAY),
GrayAlphaBits32, true, false,
Transparency.TRANSLUCENT,
DataBuffer.TYPE_INT);
private static final int[] RGBBits8 = { 8, 8, 8 };
private static final ComponentColorModel colorModelRGB8 =
new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB),
RGBBits8, false, false,
Transparency.OPAQUE,
DataBuffer.TYPE_BYTE);
private static final int[] RGBABits8 = { 8, 8, 8, 8 };
private static final ComponentColorModel colorModelRGBA8 =
new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB),
RGBABits8, true, false,
Transparency.TRANSLUCENT,
DataBuffer.TYPE_BYTE);
private static final int[] RGBBits16 = { 16, 16, 16 };
private static final ComponentColorModel colorModelRGB16 =
new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB),
RGBBits16, false, false,
Transparency.OPAQUE,
DataBuffer.TYPE_USHORT);
private static final int[] RGBABits16 = { 16, 16, 16, 16 };
private static final ComponentColorModel colorModelRGBA16 =
new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB),
RGBABits16, true, false,
Transparency.TRANSLUCENT,
DataBuffer.TYPE_USHORT);
private static final int[] RGBBits32 = { 32, 32, 32 };
private static final ComponentColorModel colorModelRGB32 =
new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB),
RGBBits32, false, false,
Transparency.OPAQUE,
DataBuffer.TYPE_INT);
private static final int[] RGBABits32 = { 32, 32, 32, 32 };
private static final ComponentColorModel colorModelRGBA32 =
new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB),
RGBABits32, true, false,
Transparency.TRANSLUCENT,
DataBuffer.TYPE_INT);
/**
* A convenience method to create an instance of
* ComponentColorModel suitable for use with the
* given SampleModel. The SampleModel
* should have a data type of DataBuffer.TYPE_BYTE,
* TYPE_USHORT, or TYPE_INT and between
* 1 and 4 bands. Depending on the number of bands of the
* SampleModel, either a gray, gray+alpha, rgb, or
* rgb+alpha ColorModel is returned.
*/
public static ColorModel createComponentColorModel(SampleModel sm) {
int type = sm.getDataType();
int bands = sm.getNumBands();
ComponentColorModel cm = null;
if (type == DataBuffer.TYPE_BYTE) {
switch (bands) {
case 1:
cm = colorModelGray8;
break;
case 2:
cm = colorModelGrayAlpha8;
break;
case 3:
cm = colorModelRGB8;
break;
case 4:
cm = colorModelRGBA8;
break;
}
} else if (type == DataBuffer.TYPE_USHORT) {
switch (bands) {
case 1:
cm = colorModelGray16;
break;
case 2:
cm = colorModelGrayAlpha16;
break;
case 3:
cm = colorModelRGB16;
break;
case 4:
cm = colorModelRGBA16;
break;
}
} else if (type == DataBuffer.TYPE_INT) {
switch (bands) {
case 1:
cm = colorModelGray32;
break;
case 2:
cm = colorModelGrayAlpha32;
break;
case 3:
cm = colorModelRGB32;
break;
case 4:
cm = colorModelRGBA32;
break;
}
}
return cm;
}
private void parse_PLTE_chunk(PNGChunk chunk) {
paletteEntries = chunk.getLength() / 3;
redPalette = new byte[paletteEntries];
greenPalette = new byte[paletteEntries];
bluePalette = new byte[paletteEntries];
int pltIndex = 0;
// gAMA chunk must precede PLTE chunk
if (performGammaCorrection) {
if (gammaLut == null) {
initGammaLut(bitDepth == 16 ? 16 : 8);
}
for (int i = 0; i < paletteEntries; i++) {
byte r = chunk.getByte(pltIndex++);
byte g = chunk.getByte(pltIndex++);
byte b = chunk.getByte(pltIndex++);
redPalette[i] = (byte)gammaLut[r & 0xff];
greenPalette[i] = (byte)gammaLut[g & 0xff];
bluePalette[i] = (byte)gammaLut[b & 0xff];
}
} else {
for (int i = 0; i < paletteEntries; i++) {
redPalette[i] = chunk.getByte(pltIndex++);
greenPalette[i] = chunk.getByte(pltIndex++);
bluePalette[i] = chunk.getByte(pltIndex++);
}
}
}
private void parse_bKGD_chunk(PNGChunk chunk) {
switch (colorType) {
case PNG_COLOR_PALETTE:
int bkgdIndex = chunk.getByte(0) & 0xff;
bkgdRed = redPalette[bkgdIndex] & 0xff;
bkgdGreen = greenPalette[bkgdIndex] & 0xff;
bkgdBlue = bluePalette[bkgdIndex] & 0xff;
if (encodeParam != null) {
((PNGEncodeParam.Palette)encodeParam).setBackgroundPaletteIndex(bkgdIndex);
}
break;
case PNG_COLOR_GRAY: case PNG_COLOR_GRAY_ALPHA:
int bkgdGray = chunk.getInt2(0);
bkgdRed = bkgdGreen = bkgdBlue = bkgdGray;
if (encodeParam != null) {
((PNGEncodeParam.Gray)encodeParam).setBackgroundGray(bkgdGray);
}
break;
case PNG_COLOR_RGB: case PNG_COLOR_RGB_ALPHA:
bkgdRed = chunk.getInt2(0);
bkgdGreen = chunk.getInt2(2);
bkgdBlue = chunk.getInt2(4);
int[] bkgdRGB = new int[3];
bkgdRGB[0] = bkgdRed;
bkgdRGB[1] = bkgdGreen;
bkgdRGB[2] = bkgdBlue;
if (encodeParam != null) {
((PNGEncodeParam.RGB)encodeParam).setBackgroundRGB(bkgdRGB);
}
break;
}
int r = 0;
int g = 0;
int b = 0;
if (bitDepth < 8) {
r = expandBits[bitDepth][bkgdRed];
g = expandBits[bitDepth][bkgdGreen];
b = expandBits[bitDepth][bkgdBlue];
} else if (bitDepth == 8) {
r = bkgdRed;
g = bkgdGreen;
b = bkgdBlue;
} else if (bitDepth == 16) {
r = bkgdRed >> 8;
g = bkgdGreen >> 8;
b = bkgdBlue >> 8;
}
if (emitProperties) {
properties.put("background_color", new Color(r, g, b));
}
}
private void parse_cHRM_chunk(PNGChunk chunk) {
// If an sRGB chunk exists, ignore cHRM chunks
if (sRGBRenderingIntent != -1) {
return;
}
chromaticity = new float[8];
chromaticity[0] = chunk.getInt4(0) / 100000.0F;
chromaticity[1] = chunk.getInt4(4) / 100000.0F;
chromaticity[2] = chunk.getInt4(8) / 100000.0F;
chromaticity[3] = chunk.getInt4(12) / 100000.0F;
chromaticity[4] = chunk.getInt4(16) / 100000.0F;
chromaticity[5] = chunk.getInt4(20) / 100000.0F;
chromaticity[6] = chunk.getInt4(24) / 100000.0F;
chromaticity[7] = chunk.getInt4(28) / 100000.0F;
if (encodeParam != null) {
encodeParam.setChromaticity(chromaticity);
}
if (emitProperties) {
properties.put("white_point_x", chromaticity[0]);
properties.put("white_point_y", chromaticity[1]);
properties.put("red_x", chromaticity[2]);
properties.put("red_y", chromaticity[3]);
properties.put("green_x", chromaticity[4]);
properties.put("green_y", chromaticity[5]);
properties.put("blue_x", chromaticity[6]);
properties.put("blue_y", chromaticity[7]);
}
}
private void parse_gAMA_chunk(PNGChunk chunk) {
// If an sRGB chunk exists, ignore gAMA chunks
if (sRGBRenderingIntent != -1) {
return;
}
fileGamma = chunk.getInt4(0) / 100000.0F;
float exp =
performGammaCorrection ? displayExponent / userExponent : 1.0F;
if (encodeParam != null) {
encodeParam.setGamma(fileGamma * exp);
}
if (emitProperties) {
properties.put("gamma", fileGamma * exp);
}
}
private void parse_hIST_chunk(PNGChunk chunk) {
if (redPalette == null) {
String msg = PropertyUtil.getString("PNGImageDecoder18");
throw new RuntimeException(msg);
}
int length = redPalette.length;
int[] hist = new int[length];
for (int i = 0; i < length; i++) {
hist[i] = chunk.getInt2(2 * i);
}
if (encodeParam != null) {
encodeParam.setPaletteHistogram(hist);
}
}
private void parse_iCCP_chunk(PNGChunk chunk) {
// String name = ""; // todo simplify this
// byte b;
// int textIndex = 0;
// while ((b = chunk.getByte(textIndex++)) != 0) {
// name += (char)b;
// }
}
private void parse_pHYs_chunk(PNGChunk chunk) {
xPixelsPerUnit = chunk.getInt4(0);
yPixelsPerUnit = chunk.getInt4(4);
unitSpecifier = chunk.getInt1(8);
if (encodeParam != null) {
encodeParam.setPhysicalDimension(xPixelsPerUnit,
yPixelsPerUnit,
unitSpecifier);
}
if (emitProperties) {
properties.put("x_pixels_per_unit", xPixelsPerUnit);
properties.put("y_pixels_per_unit", yPixelsPerUnit);
properties.put("pixel_aspect_ratio",
(float) xPixelsPerUnit / yPixelsPerUnit);
if (unitSpecifier == 1) {
properties.put("pixel_units", "Meters");
} else if (unitSpecifier != 0) {
// Error -- unit specifier must be 0 or 1
String msg = PropertyUtil.getString("PNGImageDecoder12");
throw new RuntimeException(msg);
}
}
}
private void parse_sBIT_chunk(PNGChunk chunk) {
if (colorType == PNG_COLOR_PALETTE) {
significantBits = new int[3];
} else {
significantBits = new int[inputBands];
}
for (int i = 0; i < significantBits.length; i++) {
int bits = chunk.getByte(i);
int depth = (colorType == PNG_COLOR_PALETTE) ? 8 : bitDepth;
if (bits <= 0 || bits > depth) {
// Error -- significant bits must be between 0 and
// image bit depth.
String msg = PropertyUtil.getString("PNGImageDecoder13");
throw new RuntimeException(msg);
}
significantBits[i] = bits;
}
if (encodeParam != null) {
encodeParam.setSignificantBits(significantBits);
}
if (emitProperties) {
properties.put("significant_bits", significantBits);
}
}
private void parse_sRGB_chunk(PNGChunk chunk) {
sRGBRenderingIntent = chunk.getByte(0);
// The presence of an sRGB chunk implies particular
// settings for gamma and chroma.
fileGamma = 45455 / 100000.0F;
chromaticity = new float[8];
chromaticity[0] = 31270 / 10000.0F;
chromaticity[1] = 32900 / 10000.0F;
chromaticity[2] = 64000 / 10000.0F;
chromaticity[3] = 33000 / 10000.0F;
chromaticity[4] = 30000 / 10000.0F;
chromaticity[5] = 60000 / 10000.0F;
chromaticity[6] = 15000 / 10000.0F;
chromaticity[7] = 6000 / 10000.0F;
if (performGammaCorrection) {
// File gamma is 1/2.2
float gamma = fileGamma * (displayExponent / userExponent);
if (encodeParam != null) {
encodeParam.setGamma(gamma);
encodeParam.setChromaticity(chromaticity);
}
if (emitProperties) {
properties.put("gamma", gamma);
properties.put("white_point_x", chromaticity[0]);
properties.put("white_point_y", chromaticity[1]);
properties.put("red_x", chromaticity[2]);
properties.put("red_y", chromaticity[3]);
properties.put("green_x", chromaticity[4]);
properties.put("green_y", chromaticity[5]);
properties.put("blue_x", chromaticity[6]);
properties.put("blue_y", chromaticity[7]);
}
}
}
private void parse_tEXt_chunk(PNGChunk chunk) {
byte b;
StringBuffer key = new StringBuffer();
int textIndex = 0;
while ((b = chunk.getByte(textIndex++)) != 0) {
key.append((char)b);
}
StringBuilder value = new StringBuilder();
for (int i = textIndex; i < chunk.getLength(); i++) {
value.append((char)chunk.getByte(i));
}
textKeys.add(key.toString());
textStrings.add(value.toString());
}
private void parse_tIME_chunk(PNGChunk chunk) {
int year = chunk.getInt2(0);
int month = chunk.getInt1(2) - 1;
int day = chunk.getInt1(3);
int hour = chunk.getInt1(4);
int minute = chunk.getInt1(5);
int second = chunk.getInt1(6);
TimeZone gmt = TimeZone.getTimeZone("GMT");
GregorianCalendar cal = new GregorianCalendar(gmt);
cal.set(year, month, day,
hour, minute, second);
Date date = cal.getTime();
if (encodeParam != null) {
encodeParam.setModificationTime(date);
}
if (emitProperties) {
properties.put("timestamp", date);
}
}
private void parse_tRNS_chunk(PNGChunk chunk) {
if (colorType == PNG_COLOR_PALETTE) {
int entries = chunk.getLength();
if (entries > paletteEntries) {
// Error -- mustn't have more alpha than RGB palette entries
String msg = PropertyUtil.getString("PNGImageDecoder14");
throw new RuntimeException(msg);
}
// Load beginning of palette from the chunk
alphaPalette = new byte[paletteEntries];
for (int i = 0; i < entries; i++) {
alphaPalette[i] = chunk.getByte(i);
}
// Fill rest of palette with 255
for (int i = entries; i < paletteEntries; i++) {
alphaPalette[i] = (byte)255;
}
if (!suppressAlpha) {
if (expandPalette) {
postProcess = POST_PALETTE_TO_RGBA;
outputBands = 4;
} else {
outputHasAlphaPalette = true;
}
}
} else if (colorType == PNG_COLOR_GRAY) {
grayTransparentAlpha = chunk.getInt2(0);
if (!suppressAlpha) {
if (bitDepth < 8) {
output8BitGray = true;
maxOpacity = 255;
postProcess = POST_GRAY_LUT_ADD_TRANS;
} else {
postProcess = POST_ADD_GRAY_TRANS;
}
if (expandGrayAlpha) {
outputBands = 4;
postProcess |= POST_EXP_MASK;
} else {
outputBands = 2;
}
if (encodeParam != null) {
((PNGEncodeParam.Gray)encodeParam).setTransparentGray(grayTransparentAlpha);
}
}
} else if (colorType == PNG_COLOR_RGB) {
redTransparentAlpha = chunk.getInt2(0);
greenTransparentAlpha = chunk.getInt2(2);
blueTransparentAlpha = chunk.getInt2(4);
if (!suppressAlpha) {
outputBands = 4;
postProcess = POST_ADD_RGB_TRANS;
if (encodeParam != null) {
int[] rgbTrans = new int[3];
rgbTrans[0] = redTransparentAlpha;
rgbTrans[1] = greenTransparentAlpha;
rgbTrans[2] = blueTransparentAlpha;
((PNGEncodeParam.RGB)encodeParam).setTransparentRGB(rgbTrans);
}
}
} else if (colorType == PNG_COLOR_GRAY_ALPHA
|| colorType == PNG_COLOR_RGB_ALPHA) {
// Error -- GA or RGBA image can't have a tRNS chunk.
String msg = PropertyUtil.getString("PNGImageDecoder15");
throw new RuntimeException(msg);
}
}
private void parse_zTXt_chunk(PNGChunk chunk) {
int textIndex = 0;
StringBuffer key = new StringBuffer();
byte b;
while ((b = chunk.getByte(textIndex++)) != 0) {
key.append((char)b);
}
// skip method
textIndex++;
StringBuffer value = new StringBuffer();
try {
int length = chunk.getLength() - textIndex;
byte[] data = chunk.getData();
InputStream cis =
new ByteArrayInputStream(data, textIndex, length);
InputStream iis = new InflaterInputStream(cis);
int c;
while ((c = iis.read()) != -1) {
value.append((char)c);
}
ztextKeys.add(key.toString());
ztextStrings.add(value.toString());
} catch (Exception e) {
e.printStackTrace();
}
}
private WritableRaster createRaster(int width, int height, int bands,
int scanlineStride,
int bitDepth) {
DataBuffer dataBuffer;
WritableRaster ras = null;
Point origin = new Point(0, 0);
if ((bitDepth < 8) && (bands == 1)) {
dataBuffer = new DataBufferByte(height * scanlineStride);
ras = Raster.createPackedRaster(dataBuffer,
width, height,
bitDepth,
origin);
} else if (bitDepth <= 8) {
dataBuffer = new DataBufferByte(height * scanlineStride);
ras = Raster.createInterleavedRaster(dataBuffer,
width, height,
scanlineStride,
bands,
bandOffsets[bands],
origin);
} else {
dataBuffer = new DataBufferUShort(height * scanlineStride);
ras = Raster.createInterleavedRaster(dataBuffer,
width, height,
scanlineStride,
bands,
bandOffsets[bands],
origin);
}
return ras;
}
// Data filtering methods
private static void decodeSubFilter(byte[] curr, int count, int bpp) {
for (int i = bpp; i < count; i++) {
int val;
val = curr[i] & 0xff;
val += curr[i - bpp] & 0xff;
curr[i] = (byte)val;
}
}
private static void decodeUpFilter(byte[] curr, byte[] prev,
int count) {
for (int i = 0; i < count; i++) {
int raw = curr[i] & 0xff;
int prior = prev[i] & 0xff;
curr[i] = (byte)(raw + prior);
}
}
private static void decodeAverageFilter(byte[] curr, byte[] prev,
int count, int bpp) {
int raw;
int priorPixel;
int priorRow;
for (int i = 0; i < bpp; i++) {
raw = curr[i] & 0xff;
priorRow = prev[i] & 0xff;
curr[i] = (byte)(raw + priorRow / 2);
}
for (int i = bpp; i < count; i++) {
raw = curr[i] & 0xff;
priorPixel = curr[i - bpp] & 0xff;
priorRow = prev[i] & 0xff;
curr[i] = (byte)(raw + (priorPixel + priorRow) / 2);
}
}
private static void decodePaethFilter(byte[] curr, byte[] prev,
int count, int bpp) {
int raw;
int priorPixel;
int priorRow;
int priorRowPixel;
for (int i = 0; i < bpp; i++) {
raw = curr[i] & 0xff;
priorRow = prev[i] & 0xff;
curr[i] = (byte)(raw + priorRow);
}
for (int i = bpp; i < count; i++) {
raw = curr[i] & 0xff;
priorPixel = curr[i - bpp] & 0xff;
priorRow = prev[i] & 0xff;
priorRowPixel = prev[i - bpp] & 0xff;
curr[i] = (byte)(raw + PNGEncodeParam.paethPredictor(priorPixel,
priorRow,
priorRowPixel));
}
}
private void processPixels(int process,
Raster src, WritableRaster dst,
int xOffset, int step, int y, int width) {
int srcX;
int dstX;
// Create an array suitable for holding one pixel
int[] ps = src.getPixel(0, 0, (int[])null);
int[] pd = dst.getPixel(0, 0, (int[])null);
dstX = xOffset;
switch (process) {
case POST_NONE:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
dst.setPixel(dstX, y, ps);
dstX += step;
}
break;
case POST_GAMMA:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
for (int i = 0; i < inputBands; i++) {
int x = ps[i];
ps[i] = gammaLut[x];
}
dst.setPixel(dstX, y, ps);
dstX += step;
}
break;
case POST_GRAY_LUT:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
pd[0] = grayLut[ps[0]];
dst.setPixel(dstX, y, pd);
dstX += step;
}
break;
case POST_GRAY_LUT_ADD_TRANS:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
int val = ps[0];
pd[0] = grayLut[val];
if (val == grayTransparentAlpha) {
pd[1] = 0;
} else {
pd[1] = maxOpacity;
}
dst.setPixel(dstX, y, pd);
dstX += step;
}
break;
case POST_PALETTE_TO_RGB:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
int val = ps[0];
pd[0] = redPalette[val];
pd[1] = greenPalette[val];
pd[2] = bluePalette[val];
dst.setPixel(dstX, y, pd);
dstX += step;
}
break;
case POST_PALETTE_TO_RGBA:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
int val = ps[0];
pd[0] = redPalette[val];
pd[1] = greenPalette[val];
pd[2] = bluePalette[val];
pd[3] = alphaPalette[val];
dst.setPixel(dstX, y, pd);
dstX += step;
}
break;
case POST_ADD_GRAY_TRANS:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
int val = ps[0];
if (performGammaCorrection) {
val = gammaLut[val];
}
pd[0] = val;
if (val == grayTransparentAlpha) {
pd[1] = 0;
} else {
pd[1] = maxOpacity;
}
dst.setPixel(dstX, y, pd);
dstX += step;
}
break;
case POST_ADD_RGB_TRANS:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
int r = ps[0];
int g = ps[1];
int b = ps[2];
if (performGammaCorrection) {
pd[0] = gammaLut[r];
pd[1] = gammaLut[g];
pd[2] = gammaLut[b];
} else {
pd[0] = r;
pd[1] = g;
pd[2] = b;
}
if ((r == redTransparentAlpha)
&& (g == greenTransparentAlpha)
&& (b == blueTransparentAlpha)) {
pd[3] = 0;
} else {
pd[3] = maxOpacity;
}
dst.setPixel(dstX, y, pd);
dstX += step;
}
break;
case POST_REMOVE_GRAY_TRANS:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
int g = ps[0];
if (performGammaCorrection) {
pd[0] = gammaLut[g];
} else {
pd[0] = g;
}
dst.setPixel(dstX, y, pd);
dstX += step;
}
break;
case POST_REMOVE_RGB_TRANS:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
int r = ps[0];
int g = ps[1];
int b = ps[2];
if (performGammaCorrection) {
pd[0] = gammaLut[r];
pd[1] = gammaLut[g];
pd[2] = gammaLut[b];
} else {
pd[0] = r;
pd[1] = g;
pd[2] = b;
}
dst.setPixel(dstX, y, pd);
dstX += step;
}
break;
case POST_GAMMA_EXP:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
int val = ps[0];
int alpha = ps[1];
int gamma = gammaLut[val];
pd[0] = gamma;
pd[1] = gamma;
pd[2] = gamma;
pd[3] = alpha;
dst.setPixel(dstX, y, pd);
dstX += step;
}
break;
case POST_GRAY_ALPHA_EXP:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
int val = ps[0];
int alpha = ps[1];
pd[0] = val;
pd[1] = val;
pd[2] = val;
pd[3] = alpha;
dst.setPixel(dstX, y, pd);
dstX += step;
}
break;
case POST_ADD_GRAY_TRANS_EXP:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
int val = ps[0];
if (performGammaCorrection) {
val = gammaLut[val];
}
pd[0] = val;
pd[1] = val;
pd[2] = val;
if (val == grayTransparentAlpha) {
pd[3] = 0;
} else {
pd[3] = maxOpacity;
}
dst.setPixel(dstX, y, pd);
dstX += step;
}
break;
case POST_GRAY_LUT_ADD_TRANS_EXP:
for (srcX = 0; srcX < width; srcX++) {
src.getPixel(srcX, 0, ps);
int val = ps[0];
int val2 = grayLut[val];
pd[0] = val2;
pd[1] = val2;
pd[2] = val2;
if (val == grayTransparentAlpha) {
pd[3] = 0;
} else {
pd[3] = maxOpacity;
}
dst.setPixel(dstX, y, pd);
dstX += step;
}
break;
}
}
/**
* Reads in an image of a given size and returns it as a
* WritableRaster.
*/
private void decodePass(WritableRaster imRas,
int xOffset, int yOffset,
int xStep, int yStep,
int passWidth, int passHeight) {
if ((passWidth == 0) || (passHeight == 0)) {
return;
}
int bytesPerRow = (inputBands * passWidth * bitDepth + 7) / 8;
int eltsPerRow = (bitDepth == 16) ? bytesPerRow / 2 : bytesPerRow;
byte[] curr = new byte[bytesPerRow];
byte[] prior = new byte[bytesPerRow];
// Create a 1-row tall Raster to hold the data
WritableRaster passRow =
createRaster(passWidth, 1, inputBands,
eltsPerRow,
bitDepth);
DataBuffer dataBuffer = passRow.getDataBuffer();
int type = dataBuffer.getDataType();
byte[] byteData = null;
short[] shortData = null;
if (type == DataBuffer.TYPE_BYTE) {
byteData = ((DataBufferByte)dataBuffer).getData();
} else {
shortData = ((DataBufferUShort)dataBuffer).getData();
}
// Decode the (sub)image row-by-row
int srcY;
int dstY;
for (srcY = 0, dstY = yOffset;
srcY < passHeight;
srcY++, dstY += yStep) {
// Read the filter type byte and a row of data
int filter = 0;
try {
filter = dataStream.read();
dataStream.readFully(curr, 0, bytesPerRow);
} catch (Exception e) {
e.printStackTrace();
}
switch (filter) {
case PNG_FILTER_NONE:
break;
case PNG_FILTER_SUB:
decodeSubFilter(curr, bytesPerRow, bytesPerPixel);
break;
case PNG_FILTER_UP:
decodeUpFilter(curr, prior, bytesPerRow);
break;
case PNG_FILTER_AVERAGE:
decodeAverageFilter(curr, prior, bytesPerRow, bytesPerPixel);
break;
case PNG_FILTER_PAETH:
decodePaethFilter(curr, prior, bytesPerRow, bytesPerPixel);
break;
default:
// Error -- uknown filter type
String msg = PropertyUtil.getString("PNGImageDecoder16");
throw new RuntimeException(msg);
}
// Copy data into passRow byte by byte
if (bitDepth < 16) {
System.arraycopy(curr, 0, byteData, 0, bytesPerRow);
} else {
int idx = 0;
for (int j = 0; j < eltsPerRow; j++) {
shortData[j] =
(short)((curr[idx] << 8) | (curr[idx + 1] & 0xff));
idx += 2;
}
}
processPixels(postProcess,
passRow, imRas, xOffset, xStep, dstY, passWidth);
// Swap curr and prior
byte[] tmp = prior;
prior = curr;
curr = tmp;
}
}
private void decodeImage(boolean useInterlacing) {
if (!useInterlacing) {
decodePass(theTile, 0, 0, 1, 1, width, height);
} else {
decodePass(theTile, 0, 0, 8, 8, (width + 7) / 8, (height + 7) / 8);
decodePass(theTile, 4, 0, 8, 8, (width + 3) / 8, (height + 7) / 8);
decodePass(theTile, 0, 4, 4, 8, (width + 3) / 4, (height + 3) / 8);
decodePass(theTile, 2, 0, 4, 4, (width + 1) / 4, (height + 3) / 4);
decodePass(theTile, 0, 2, 2, 4, (width + 1) / 2, (height + 1) / 4);
decodePass(theTile, 1, 0, 2, 2, width / 2, (height + 1) / 2);
decodePass(theTile, 0, 1, 1, 2, width, height / 2);
}
}
// RenderedImage stuff
public Raster getTile(int tileX, int tileY) {
if (tileX != 0 || tileY != 0) {
// Error -- bad tile requested
String msg = PropertyUtil.getString("PNGImageDecoder17");
throw new IllegalArgumentException(msg);
}
return theTile;
}
}