com.lowagie.text.pdf.codec.PngImage Maven / Gradle / Ivy
/*
* Copyright 2003-2008 by Paulo Soares.
*
* The contents of this file are subject to the Mozilla Public License Version 1.1
* (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the License.
*
* The Original Code is 'iText, a free JAVA-PDF library'.
*
* The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
* the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
* All Rights Reserved.
* Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
* are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
*
* Contributor(s): all the names of the contributors are added in the source code
* where applicable.
*
* Alternatively, the contents of this file may be used under the terms of the
* LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
* provisions of LGPL are applicable instead of those above. If you wish to
* allow use of your version of this file only under the terms of the LGPL
* License and not to allow others to use your version of this file under
* the MPL, indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by the LGPL.
* If you do not delete the provisions above, a recipient may use your version
* of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the MPL as stated above or under the terms of the GNU
* Library General Public License as published by the Free Software Foundation;
* either version 2 of the License, or any later version.
*
* This library 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 Library general Public License for more
* details.
*
* If you didn't download this code from the following link, you should check if
* you aren't using an obsolete version:
* http://www.lowagie.com/iText/
*
* This code is based on a series of source files originally released
* by SUN in the context of the JAI project. The original code was released
* under the BSD license in a specific wording. In a mail dating from
* January 23, 2008, Brian Burkhalter (@sun.com) gave us permission
* to use the code under the following version of the BSD license:
*
* Copyright (c) 2005 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistribution of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistribution in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any
* kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
* WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
* EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL
* NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF
* USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR
* ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
* CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
* REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
* INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed or intended for
* use in the design, construction, operation or maintenance of any
* nuclear facility.
*/
package com.lowagie.text.pdf.codec;
import java.awt.color.ICC_Profile;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;
import com.lowagie.text.error_messages.MessageLocalization;
import com.lowagie.text.ExceptionConverter;
import com.lowagie.text.Image;
import com.lowagie.text.ImgRaw;
import com.lowagie.text.Utilities;
import com.lowagie.text.pdf.ByteBuffer;
import com.lowagie.text.pdf.PdfArray;
import com.lowagie.text.pdf.PdfDictionary;
import com.lowagie.text.pdf.PdfLiteral;
import com.lowagie.text.pdf.PdfName;
import com.lowagie.text.pdf.PdfNumber;
import com.lowagie.text.pdf.PdfObject;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfString;
/** Reads a PNG image. All types of PNG can be read.
*
* It is based in part in the JAI codec.
*
* @author Paulo Soares ([email protected])
*/
public class PngImage {
/** Some PNG specific values. */
public static final int[] PNGID = {137, 80, 78, 71, 13, 10, 26, 10};
/** A PNG marker. */
public static final String IHDR = "IHDR";
/** A PNG marker. */
public static final String PLTE = "PLTE";
/** A PNG marker. */
public static final String IDAT = "IDAT";
/** A PNG marker. */
public static final String IEND = "IEND";
/** A PNG marker. */
public static final String tRNS = "tRNS";
/** A PNG marker. */
public static final String pHYs = "pHYs";
/** A PNG marker. */
public static final String gAMA = "gAMA";
/** A PNG marker. */
public static final String cHRM = "cHRM";
/** A PNG marker. */
public static final String sRGB = "sRGB";
/** A PNG marker. */
public static final String iCCP = "iCCP";
private static final int TRANSFERSIZE = 4096;
private static final int PNG_FILTER_NONE = 0;
private static final int PNG_FILTER_SUB = 1;
private static final int PNG_FILTER_UP = 2;
private static final int PNG_FILTER_AVERAGE = 3;
private static final int PNG_FILTER_PAETH = 4;
private static final PdfName intents[] = {PdfName.PERCEPTUAL,
PdfName.RELATIVECOLORIMETRIC,PdfName.SATURATION,PdfName.ABSOLUTECOLORIMETRIC};
InputStream is;
DataInputStream dataStream;
int width;
int height;
int bitDepth;
int colorType;
int compressionMethod;
int filterMethod;
int interlaceMethod;
PdfDictionary additional = new PdfDictionary();
byte image[];
byte smask[];
byte trans[];
NewByteArrayOutputStream idat = new NewByteArrayOutputStream();
int dpiX;
int dpiY;
float XYRatio;
boolean genBWMask;
boolean palShades;
int transRedGray = -1;
int transGreen = -1;
int transBlue = -1;
int inputBands;
int bytesPerPixel; // number of bytes per input pixel
byte colorTable[];
float gamma = 1f;
boolean hasCHRM = false;
float xW, yW, xR, yR, xG, yG, xB, yB;
PdfName intent;
ICC_Profile icc_profile;
/** Creates a new instance of PngImage */
PngImage(InputStream is) {
this.is = is;
}
/** Reads a PNG from an url.
* @param url the url
* @throws IOException on error
* @return the image
*/
public static Image getImage(URL url) throws IOException {
InputStream is = null;
try {
is = url.openStream();
Image img = getImage(is);
img.setUrl(url);
return img;
}
finally {
if (is != null) {
is.close();
}
}
}
/** Reads a PNG from a stream.
* @param is the stream
* @throws IOException on error
* @return the image
*/
public static Image getImage(InputStream is) throws IOException {
PngImage png = new PngImage(is);
return png.getImage();
}
/** Reads a PNG from a file.
* @param file the file
* @throws IOException on error
* @return the image
*/
public static Image getImage(String file) throws IOException {
return getImage(Utilities.toURL(file));
}
/** Reads a PNG from a byte array.
* @param data the byte array
* @throws IOException on error
* @return the image
*/
public static Image getImage(byte data[]) throws IOException {
ByteArrayInputStream is = new ByteArrayInputStream(data);
Image img = getImage(is);
img.setOriginalData(data);
return img;
}
boolean checkMarker(String s) {
if (s.length() != 4)
return false;
for (int k = 0; k < 4; ++k) {
char c = s.charAt(k);
if ((c < 'a' || c > 'z') && (c < 'A' || c > 'Z'))
return false;
}
return true;
}
void readPng() throws IOException {
for (int i = 0; i < PNGID.length; i++) {
if (PNGID[i] != is.read()) {
throw new IOException(MessageLocalization.getComposedMessage("file.is.not.a.valid.png"));
}
}
byte buffer[] = new byte[TRANSFERSIZE];
while (true) {
int len = getInt(is);
String marker = getString(is);
if (len < 0 || !checkMarker(marker))
throw new IOException(MessageLocalization.getComposedMessage("corrupted.png.file"));
if (IDAT.equals(marker)) {
int size;
while (len != 0) {
size = is.read(buffer, 0, Math.min(len, TRANSFERSIZE));
if (size < 0)
return;
idat.write(buffer, 0, size);
len -= size;
}
}
else if (tRNS.equals(marker)) {
switch (colorType) {
case 0:
if (len >= 2) {
len -= 2;
int gray = getWord(is);
if (bitDepth == 16)
transRedGray = gray;
else
additional.put(PdfName.MASK, new PdfLiteral("["+gray+" "+gray+"]"));
}
break;
case 2:
if (len >= 6) {
len -= 6;
int red = getWord(is);
int green = getWord(is);
int blue = getWord(is);
if (bitDepth == 16) {
transRedGray = red;
transGreen = green;
transBlue = blue;
}
else
additional.put(PdfName.MASK, new PdfLiteral("["+red+" "+red+" "+green+" "+green+" "+blue+" "+blue+"]"));
}
break;
case 3:
if (len > 0) {
trans = new byte[len];
for (int k = 0; k < len; ++k)
trans[k] = (byte)is.read();
len = 0;
}
break;
}
Utilities.skip(is, len);
}
else if (IHDR.equals(marker)) {
width = getInt(is);
height = getInt(is);
bitDepth = is.read();
colorType = is.read();
compressionMethod = is.read();
filterMethod = is.read();
interlaceMethod = is.read();
}
else if (PLTE.equals(marker)) {
if (colorType == 3) {
PdfArray colorspace = new PdfArray();
colorspace.add(PdfName.INDEXED);
colorspace.add(getColorspace());
colorspace.add(new PdfNumber(len / 3 - 1));
ByteBuffer colortable = new ByteBuffer();
while ((len--) > 0) {
colortable.append_i(is.read());
}
colorspace.add(new PdfString(colorTable = colortable.toByteArray()));
additional.put(PdfName.COLORSPACE, colorspace);
}
else {
Utilities.skip(is, len);
}
}
else if (pHYs.equals(marker)) {
int dx = getInt(is);
int dy = getInt(is);
int unit = is.read();
if (unit == 1) {
dpiX = (int)(dx * 0.0254f + 0.5f);
dpiY = (int)(dy * 0.0254f + 0.5f);
}
else {
if (dy != 0)
XYRatio = (float)dx / (float)dy;
}
}
else if (cHRM.equals(marker)) {
xW = getInt(is) / 100000f;
yW = getInt(is) / 100000f;
xR = getInt(is) / 100000f;
yR = getInt(is) / 100000f;
xG = getInt(is) / 100000f;
yG = getInt(is) / 100000f;
xB = getInt(is) / 100000f;
yB = getInt(is) / 100000f;
hasCHRM = !(Math.abs(xW)<0.0001f||Math.abs(yW)<0.0001f||Math.abs(xR)<0.0001f||Math.abs(yR)<0.0001f||Math.abs(xG)<0.0001f||Math.abs(yG)<0.0001f||Math.abs(xB)<0.0001f||Math.abs(yB)<0.0001f);
}
else if (sRGB.equals(marker)) {
int ri = is.read();
intent = intents[ri];
gamma = 2.2f;
xW = 0.3127f;
yW = 0.329f;
xR = 0.64f;
yR = 0.33f;
xG = 0.3f;
yG = 0.6f;
xB = 0.15f;
yB = 0.06f;
hasCHRM = true;
}
else if (gAMA.equals(marker)) {
int gm = getInt(is);
if (gm != 0) {
gamma = 100000f / gm;
if (!hasCHRM) {
xW = 0.3127f;
yW = 0.329f;
xR = 0.64f;
yR = 0.33f;
xG = 0.3f;
yG = 0.6f;
xB = 0.15f;
yB = 0.06f;
hasCHRM = true;
}
}
}
else if (iCCP.equals(marker)) {
do {
--len;
} while (is.read() != 0);
is.read();
--len;
byte icccom[] = new byte[len];
int p = 0;
while (len > 0) {
int r = is.read(icccom, p, len);
if (r < 0)
throw new IOException(MessageLocalization.getComposedMessage("premature.end.of.file"));
p += r;
len -= r;
}
byte iccp[] = PdfReader.FlateDecode(icccom, true);
icccom = null;
try {
icc_profile = ICC_Profile.getInstance(iccp);
}
catch (RuntimeException e) {
icc_profile = null;
}
}
else if (IEND.equals(marker)) {
break;
}
else {
Utilities.skip(is, len);
}
Utilities.skip(is, 4);
}
}
PdfObject getColorspace() {
if (icc_profile != null) {
if ((colorType & 2) == 0)
return PdfName.DEVICEGRAY;
else
return PdfName.DEVICERGB;
}
if (gamma == 1f && !hasCHRM) {
if ((colorType & 2) == 0)
return PdfName.DEVICEGRAY;
else
return PdfName.DEVICERGB;
}
else {
PdfArray array = new PdfArray();
PdfDictionary dic = new PdfDictionary();
if ((colorType & 2) == 0) {
if (gamma == 1f)
return PdfName.DEVICEGRAY;
array.add(PdfName.CALGRAY);
dic.put(PdfName.GAMMA, new PdfNumber(gamma));
dic.put(PdfName.WHITEPOINT, new PdfLiteral("[1 1 1]"));
array.add(dic);
}
else {
PdfObject wp = new PdfLiteral("[1 1 1]");
array.add(PdfName.CALRGB);
if (gamma != 1f) {
PdfArray gm = new PdfArray();
PdfNumber n = new PdfNumber(gamma);
gm.add(n);
gm.add(n);
gm.add(n);
dic.put(PdfName.GAMMA, gm);
}
if (hasCHRM) {
float z = yW*((xG-xB)*yR-(xR-xB)*yG+(xR-xG)*yB);
float YA = yR*((xG-xB)*yW-(xW-xB)*yG+(xW-xG)*yB)/z;
float XA = YA*xR/yR;
float ZA = YA*((1-xR)/yR-1);
float YB = -yG*((xR-xB)*yW-(xW-xB)*yR+(xW-xR)*yB)/z;
float XB = YB*xG/yG;
float ZB = YB*((1-xG)/yG-1);
float YC = yB*((xR-xG)*yW-(xW-xG)*yW+(xW-xR)*yG)/z;
float XC = YC*xB/yB;
float ZC = YC*((1-xB)/yB-1);
float XW = XA+XB+XC;
float YW = 1;//YA+YB+YC;
float ZW = ZA+ZB+ZC;
PdfArray wpa = new PdfArray();
wpa.add(new PdfNumber(XW));
wpa.add(new PdfNumber(YW));
wpa.add(new PdfNumber(ZW));
wp = wpa;
PdfArray matrix = new PdfArray();
matrix.add(new PdfNumber(XA));
matrix.add(new PdfNumber(YA));
matrix.add(new PdfNumber(ZA));
matrix.add(new PdfNumber(XB));
matrix.add(new PdfNumber(YB));
matrix.add(new PdfNumber(ZB));
matrix.add(new PdfNumber(XC));
matrix.add(new PdfNumber(YC));
matrix.add(new PdfNumber(ZC));
dic.put(PdfName.MATRIX, matrix);
}
dic.put(PdfName.WHITEPOINT, wp);
array.add(dic);
}
return array;
}
}
Image getImage() throws IOException {
readPng();
try {
int pal0 = 0;
int palIdx = 0;
palShades = false;
if (trans != null) {
for (int k = 0; k < trans.length; ++k) {
int n = trans[k] & 0xff;
if (n == 0) {
++pal0;
palIdx = k;
}
if (n != 0 && n != 255) {
palShades = true;
break;
}
}
}
if ((colorType & 4) != 0)
palShades = true;
genBWMask = (!palShades && (pal0 > 1 || transRedGray >= 0));
if (!palShades && !genBWMask && pal0 == 1) {
additional.put(PdfName.MASK, new PdfLiteral("["+palIdx+" "+palIdx+"]"));
}
boolean needDecode = (interlaceMethod == 1) || (bitDepth == 16) || ((colorType & 4) != 0) || palShades || genBWMask;
switch (colorType) {
case 0:
inputBands = 1;
break;
case 2:
inputBands = 3;
break;
case 3:
inputBands = 1;
break;
case 4:
inputBands = 2;
break;
case 6:
inputBands = 4;
break;
}
if (needDecode)
decodeIdat();
int components = inputBands;
if ((colorType & 4) != 0)
--components;
int bpc = bitDepth;
if (bpc == 16)
bpc = 8;
Image img;
if (image != null) {
if (colorType == 3)
img = new ImgRaw(width, height, components, bpc, image);
else
img = Image.getInstance(width, height, components, bpc, image);
}
else {
img = new ImgRaw(width, height, components, bpc, idat.toByteArray());
img.setDeflated(true);
PdfDictionary decodeparms = new PdfDictionary();
decodeparms.put(PdfName.BITSPERCOMPONENT, new PdfNumber(bitDepth));
decodeparms.put(PdfName.PREDICTOR, new PdfNumber(15));
decodeparms.put(PdfName.COLUMNS, new PdfNumber(width));
decodeparms.put(PdfName.COLORS, new PdfNumber((colorType == 3 || (colorType & 2) == 0) ? 1 : 3));
additional.put(PdfName.DECODEPARMS, decodeparms);
}
if (additional.get(PdfName.COLORSPACE) == null)
additional.put(PdfName.COLORSPACE, getColorspace());
if (intent != null)
additional.put(PdfName.INTENT, intent);
if (additional.size() > 0)
img.setAdditional(additional);
if (icc_profile != null)
img.tagICC(icc_profile);
if (palShades) {
Image im2 = Image.getInstance(width, height, 1, 8, smask);
im2.makeMask();
img.setImageMask(im2);
}
if (genBWMask) {
Image im2 = Image.getInstance(width, height, 1, 1, smask);
im2.makeMask();
img.setImageMask(im2);
}
img.setDpi(dpiX, dpiY);
img.setXYRatio(XYRatio);
img.setOriginalType(Image.ORIGINAL_PNG);
return img;
}
catch (Exception e) {
throw new ExceptionConverter(e);
}
}
void decodeIdat() {
int nbitDepth = bitDepth;
if (nbitDepth == 16)
nbitDepth = 8;
int size = -1;
bytesPerPixel = (bitDepth == 16) ? 2 : 1;
switch (colorType) {
case 0:
size = (nbitDepth * width + 7) / 8 * height;
break;
case 2:
size = width * 3 * height;
bytesPerPixel *= 3;
break;
case 3:
if (interlaceMethod == 1)
size = (nbitDepth * width + 7) / 8 * height;
bytesPerPixel = 1;
break;
case 4:
size = width * height;
bytesPerPixel *= 2;
break;
case 6:
size = width * 3 * height;
bytesPerPixel *= 4;
break;
}
if (size >= 0)
image = new byte[size];
if (palShades)
smask = new byte[width * height];
else if (genBWMask)
smask = new byte[(width + 7) / 8 * height];
ByteArrayInputStream bai = new ByteArrayInputStream(idat.getBuf(), 0, idat.size());
InputStream infStream = new InflaterInputStream(bai, new Inflater());
dataStream = new DataInputStream(infStream);
if (interlaceMethod != 1) {
decodePass(0, 0, 1, 1, width, height);
}
else {
decodePass(0, 0, 8, 8, (width + 7)/8, (height + 7)/8);
decodePass(4, 0, 8, 8, (width + 3)/8, (height + 7)/8);
decodePass(0, 4, 4, 8, (width + 3)/4, (height + 3)/8);
decodePass(2, 0, 4, 4, (width + 1)/4, (height + 3)/4);
decodePass(0, 2, 2, 4, (width + 1)/2, (height + 1)/4);
decodePass(1, 0, 2, 2, width/2, (height + 1)/2);
decodePass(0, 1, 1, 2, width, height/2);
}
}
void decodePass( 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;
byte[] curr = new byte[bytesPerRow];
byte[] prior = new byte[bytesPerRow];
// Decode the (sub)image row-by-row
int srcY, 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) {
// empty on purpose
}
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
throw new RuntimeException(MessageLocalization.getComposedMessage("png.filter.unknown"));
}
processPixels(curr, xOffset, xStep, dstY, passWidth);
// Swap curr and prior
byte[] tmp = prior;
prior = curr;
curr = tmp;
}
}
void processPixels(byte curr[], int xOffset, int step, int y, int width) {
int srcX, dstX;
int out[] = getPixel(curr);
int sizes = 0;
switch (colorType) {
case 0:
case 3:
case 4:
sizes = 1;
break;
case 2:
case 6:
sizes = 3;
break;
}
if (image != null) {
dstX = xOffset;
int yStride = (sizes*this.width*(bitDepth == 16 ? 8 : bitDepth)+ 7)/8;
for (srcX = 0; srcX < width; srcX++) {
setPixel(image, out, inputBands * srcX, sizes, dstX, y, bitDepth, yStride);
dstX += step;
}
}
if (palShades) {
if ((colorType & 4) != 0) {
if (bitDepth == 16) {
for (int k = 0; k < width; ++k)
out[k * inputBands + sizes] >>>= 8;
}
int yStride = this.width;
dstX = xOffset;
for (srcX = 0; srcX < width; srcX++) {
setPixel(smask, out, inputBands * srcX + sizes, 1, dstX, y, 8, yStride);
dstX += step;
}
}
else { //colorType 3
int yStride = this.width;
int v[] = new int[1];
dstX = xOffset;
for (srcX = 0; srcX < width; srcX++) {
int idx = out[srcX];
if (idx < trans.length)
v[0] = trans[idx];
else
v[0] = 255; // Patrick Valsecchi
setPixel(smask, v, 0, 1, dstX, y, 8, yStride);
dstX += step;
}
}
}
else if (genBWMask) {
switch (colorType) {
case 3: {
int yStride = (this.width + 7) / 8;
int v[] = new int[1];
dstX = xOffset;
for (srcX = 0; srcX < width; srcX++) {
int idx = out[srcX];
v[0] = ((idx < trans.length && trans[idx] == 0) ? 1 : 0);
setPixel(smask, v, 0, 1, dstX, y, 1, yStride);
dstX += step;
}
break;
}
case 0: {
int yStride = (this.width + 7) / 8;
int v[] = new int[1];
dstX = xOffset;
for (srcX = 0; srcX < width; srcX++) {
int g = out[srcX];
v[0] = (g == transRedGray ? 1 : 0);
setPixel(smask, v, 0, 1, dstX, y, 1, yStride);
dstX += step;
}
break;
}
case 2: {
int yStride = (this.width + 7) / 8;
int v[] = new int[1];
dstX = xOffset;
for (srcX = 0; srcX < width; srcX++) {
int markRed = inputBands * srcX;
v[0] = (out[markRed] == transRedGray && out[markRed + 1] == transGreen
&& out[markRed + 2] == transBlue ? 1 : 0);
setPixel(smask, v, 0, 1, dstX, y, 1, yStride);
dstX += step;
}
break;
}
}
}
}
static int getPixel(byte image[], int x, int y, int bitDepth, int bytesPerRow) {
if (bitDepth == 8) {
int pos = bytesPerRow * y + x;
return image[pos] & 0xff;
}
else {
int pos = bytesPerRow * y + x / (8 / bitDepth);
int v = image[pos] >> (8 - bitDepth * (x % (8 / bitDepth))- bitDepth);
return v & ((1 << bitDepth) - 1);
}
}
static void setPixel(byte image[], int data[], int offset, int size, int x, int y, int bitDepth, int bytesPerRow) {
if (bitDepth == 8) {
int pos = bytesPerRow * y + size * x;
for (int k = 0; k < size; ++k)
image[pos + k] = (byte)data[k + offset];
}
else if (bitDepth == 16) {
int pos = bytesPerRow * y + size * x;
for (int k = 0; k < size; ++k)
image[pos + k] = (byte)(data[k + offset] >>> 8);
}
else {
int pos = bytesPerRow * y + x / (8 / bitDepth);
int v = data[offset] << (8 - bitDepth * (x % (8 / bitDepth))- bitDepth);
image[pos] |= v;
}
}
int[] getPixel(byte curr[]) {
switch (bitDepth) {
case 8: {
int out[] = new int[curr.length];
for (int k = 0; k < out.length; ++k)
out[k] = curr[k] & 0xff;
return out;
}
case 16: {
int out[] = new int[curr.length / 2];
for (int k = 0; k < out.length; ++k)
out[k] = ((curr[k * 2] & 0xff) << 8) + (curr[k * 2 + 1] & 0xff);
return out;
}
default: {
int out[] = new int[curr.length * 8 / bitDepth];
int idx = 0;
int passes = 8 / bitDepth;
int mask = (1 << bitDepth) - 1;
for (int k = 0; k < curr.length; ++k) {
for (int j = passes - 1; j >= 0; --j) {
out[idx++] = (curr[k] >>> (bitDepth * j)) & mask;
}
}
return out;
}
}
}
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, priorPixel, 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 int paethPredictor(int a, int b, int c) {
int p = a + b - c;
int pa = Math.abs(p - a);
int pb = Math.abs(p - b);
int pc = Math.abs(p - c);
if ((pa <= pb) && (pa <= pc)) {
return a;
} else if (pb <= pc) {
return b;
} else {
return c;
}
}
private static void decodePaethFilter(byte[] curr, byte[] prev,
int count, int bpp) {
int raw, priorPixel, priorRow, 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 + paethPredictor(priorPixel,
priorRow,
priorRowPixel));
}
}
static class NewByteArrayOutputStream extends ByteArrayOutputStream {
public byte[] getBuf() {
return buf;
}
}
/**
* Gets an int from an InputStream.
*
* @param is an InputStream
* @return the value of an int
*/
public static final int getInt(InputStream is) throws IOException {
return (is.read() << 24) + (is.read() << 16) + (is.read() << 8) + is.read();
}
/**
* Gets a word from an InputStream.
*
* @param is an InputStream
* @return the value of an int
*/
public static final int getWord(InputStream is) throws IOException {
return (is.read() << 8) + is.read();
}
/**
* Gets a String from an InputStream.
*
* @param is an InputStream
* @return the value of an int
*/
public static final String getString(InputStream is) throws IOException {
StringBuffer buf = new StringBuffer();
for (int i = 0; i < 4; i++) {
buf.append((char)is.read());
}
return buf.toString();
}
}