Mega Code Archive
PNG Decoder
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/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common
* Development and Distribution License("CDDL") (collectively, the
* "License"). You may not use this file except in compliance with the
* License. You can obtain a copy of the License at
* http://www.netbeans.org/cddl-gplv2.html
* or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
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* Notice in each file and include the License file at
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* particular file as subject to the "Classpath" exception as provided
* by Sun in the GPL Version 2 section of the License file that
* accompanied this code. If applicable, add the following below the
* License Header, with the fields enclosed by brackets [] replaced by
* your own identifying information:
* "Portions Copyrighted [year] [name of copyright owner]"
*
* Contributor(s): Alexandre Iline.
*
* The Original Software is the Jemmy library.
* The Initial Developer of the Original Software is Alexandre Iline.
* All Rights Reserved.
*
* If you wish your version of this file to be governed by only the CDDL
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* under the [CDDL or GPL Version 2] license." If you do not indicate a
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* your version of this file under either the CDDL, the GPL Version 2 or
* to extend the choice of license to its licensees as provided above.
* However, if you add GPL Version 2 code and therefore, elected the GPL
* Version 2 license, then the option applies only if the new code is
* made subject to such option by the copyright holder.
*
*
*
* $Id$ $Revision$ $Date$
*
*/
import java.awt.AWTException;
import java.awt.Color;
import java.awt.Component;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.zip.CRC32;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.Inflater;
/**
* Allows to load PNG graphical file.
* @author Alexandre Iline
*/
public class PNGDecoder extends Object {
InputStream in;
/**
* Constructs a PNGDecoder object.
* @param in input stream to read PNG image from.
*/
public PNGDecoder(InputStream in) {
this.in = in;
}
byte read() throws IOException {
byte b = (byte)in.read();
return(b);
}
int readInt() throws IOException {
byte b[] = read(4);
return(((b[0]&0xff)<<24) +
((b[1]&0xff)<<16) +
((b[2]&0xff)<<8) +
((b[3]&0xff)));
}
byte[] read(int count) throws IOException {
byte[] result = new byte[count];
for(int i = 0; i < count; i++) {
result[i] = read();
}
return(result);
}
boolean compare(byte[] b1, byte[] b2) {
if(b1.length != b2.length) {
return(false);
}
for(int i = 0; i < b1.length; i++) {
if(b1[i] != b2[i]) {
return(false);
}
}
return(true);
}
void checkEquality(byte[] b1, byte[] b2) {
if(!compare(b1, b2)) {
throw(new RuntimeException("Format error"));
}
}
/**
* Decodes image from an input stream passed into constructor.
* @return a BufferedImage object
* @throws IOException
*/
public BufferedImage decode() throws IOException {
byte[] id = read(12);
checkEquality(id, new byte[] {-119, 80, 78, 71, 13, 10, 26, 10, 0, 0, 0, 13});
byte[] ihdr = read(4);
checkEquality(ihdr, "IHDR".getBytes());
int width = readInt();
int height = readInt();
BufferedImage result = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
byte[] head = read(5);
int mode;
if(compare(head, new byte[]{1, 0, 0, 0, 0})) {
mode = PNGEncoder.BW_MODE;
} else if(compare(head, new byte[]{8, 0, 0, 0, 0})) {
mode = PNGEncoder.GREYSCALE_MODE;
} else if(compare(head, new byte[]{8, 2, 0, 0, 0})) {
mode = PNGEncoder.COLOR_MODE;
} else {
throw(new RuntimeException("Format error"));
}
readInt();//!!crc
int size = readInt();
byte[] idat = read(4);
checkEquality(idat, "IDAT".getBytes());
byte[] data = read(size);
Inflater inflater = new Inflater();
inflater.setInput(data, 0, size);
int color;
try {
switch (mode) {
case PNGEncoder.BW_MODE:
{
int bytes = (int)(width / 8);
if((width % 8) != 0) {
bytes++;
}
byte colorset;
byte[] row = new byte[bytes];
for (int y = 0; y < height; y++) {
inflater.inflate(new byte[1]);
inflater.inflate(row);
for (int x = 0; x < bytes; x++) {
colorset = row[x];
for (int sh = 0; sh < 8; sh++) {
if(x * 8 + sh >= width) {
break;
}
if((colorset & 0x80) == 0x80) {
result.setRGB(x * 8 + sh, y, Color.white.getRGB());
} else {
result.setRGB(x * 8 + sh, y, Color.black.getRGB());
}
colorset <<= 1;
}
}
}
}
break;
case PNGEncoder.GREYSCALE_MODE:
{
byte[] row = new byte[width];
for (int y = 0; y < height; y++) {
inflater.inflate(new byte[1]);
inflater.inflate(row);
for (int x = 0; x < width; x++) {
color = row[x];
result.setRGB(x, y, (color << 16) + (color << 8) + color);
}
}
}
break;
case PNGEncoder.COLOR_MODE:
{
byte[] row = new byte[width * 3];
for (int y = 0; y < height; y++) {
inflater.inflate(new byte[1]);
inflater.inflate(row);
for (int x = 0; x < width; x++) {
result.setRGB(x, y,
((row[x * 3 + 0]&0xff) << 16) +
((row[x * 3 + 1]&0xff) << 8) +
((row[x * 3 + 2]&0xff)));
}
}
}
}
} catch(DataFormatException e) {
throw(new RuntimeException("ZIP error"+e));
}
readInt();//!!crc
readInt();//0
byte[] iend = read(4);
checkEquality(iend, "IEND".getBytes());
readInt();//!!crc
in.close();
return(result);
}
/**
* Decodes image from file.
* @param fileName a file to read image from
* @return a BufferedImage instance.
*/
public static BufferedImage decode(String fileName) {
try {
return(new PNGDecoder(new FileInputStream(fileName)).decode());
} catch(IOException e) {
throw(new RuntimeException("IOException during image reading"+ e));
}
}
}
class PNGEncoder extends Object {
/** black and white image mode. */
public static final byte BW_MODE = 0;
/** grey scale image mode. */
public static final byte GREYSCALE_MODE = 1;
/** full color image mode. */
public static final byte COLOR_MODE = 2;
OutputStream out;
CRC32 crc;
byte mode;
/** public constructor of PNGEncoder class with greyscale mode by default.
* @param out output stream for PNG image format to write into
*/
public PNGEncoder(OutputStream out) {
this(out, GREYSCALE_MODE);
}
/** public constructor of PNGEncoder class.
* @param out output stream for PNG image format to write into
* @param mode BW_MODE, GREYSCALE_MODE or COLOR_MODE
*/
public PNGEncoder(OutputStream out, byte mode) {
crc=new CRC32();
this.out = out;
if (mode<0 || mode>2)
throw new IllegalArgumentException("Unknown color mode");
this.mode = mode;
}
void write(int i) throws IOException {
byte b[]={(byte)((i>>24)&0xff),(byte)((i>>16)&0xff),(byte)((i>>8)&0xff),(byte)(i&0xff)};
write(b);
}
void write(byte b[]) throws IOException {
out.write(b);
crc.update(b);
}
/** main encoding method (stays blocked till encoding is finished).
* @param image BufferedImage to encode
* @throws IOException IOException
*/
public void encode(BufferedImage image) throws IOException {
int width = image.getWidth(null);
int height = image.getHeight(null);
final byte id[] = {-119, 80, 78, 71, 13, 10, 26, 10, 0, 0, 0, 13};
write(id);
crc.reset();
write("IHDR".getBytes());
write(width);
write(height);
byte head[]=null;
switch (mode) {
case BW_MODE: head=new byte[]{1, 0, 0, 0, 0}; break;
case GREYSCALE_MODE: head=new byte[]{8, 0, 0, 0, 0}; break;
case COLOR_MODE: head=new byte[]{8, 2, 0, 0, 0}; break;
}
write(head);
write((int) crc.getValue());
ByteArrayOutputStream compressed = new ByteArrayOutputStream(65536);
BufferedOutputStream bos = new BufferedOutputStream( new DeflaterOutputStream(compressed, new Deflater(9)));
int pixel;
int color;
int colorset;
switch (mode) {
case BW_MODE:
int rest=width%8;
int bytes=width/8;
for (int y=0;y<height;y++) {
bos.write(0);
for (int x=0;x<bytes;x++) {
colorset=0;
for (int sh=0; sh<8; sh++) {
pixel=image.getRGB(x*8+sh,y);
color=((pixel >> 16) & 0xff);
color+=((pixel >> 8) & 0xff);
color+=(pixel & 0xff);
colorset<<=1;
if (color>=3*128)
colorset|=1;
}
bos.write((byte)colorset);
}
if (rest>0) {
colorset=0;
for (int sh=0; sh<width%8; sh++) {
pixel=image.getRGB(bytes*8+sh,y);
color=((pixel >> 16) & 0xff);
color+=((pixel >> 8) & 0xff);
color+=(pixel & 0xff);
colorset<<=1;
if (color>=3*128)
colorset|=1;
}
colorset<<=8-rest;
bos.write((byte)colorset);
}
}
break;
case GREYSCALE_MODE:
for (int y=0;y<height;y++) {
bos.write(0);
for (int x=0;x<width;x++) {
pixel=image.getRGB(x,y);
color=((pixel >> 16) & 0xff);
color+=((pixel >> 8) & 0xff);
color+=(pixel & 0xff);
bos.write((byte)(color/3));
}
}
break;
case COLOR_MODE:
for (int y=0;y<height;y++) {
bos.write(0);
for (int x=0;x<width;x++) {
pixel=image.getRGB(x,y);
bos.write((byte)((pixel >> 16) & 0xff));
bos.write((byte)((pixel >> 8) & 0xff));
bos.write((byte)(pixel & 0xff));
}
}
break;
}
bos.close();
write(compressed.size());
crc.reset();
write("IDAT".getBytes());
write(compressed.toByteArray());
write((int) crc.getValue());
write(0);
crc.reset();
write("IEND".getBytes());
write((int) crc.getValue());
out.close();
}
/** Static method performing screen capture into PNG image format file with given fileName.
* @param rect Rectangle of screen to be captured
* @param fileName file name for screen capture PNG image file */
public static void captureScreen(Rectangle rect, String fileName) {
captureScreen(rect, fileName, GREYSCALE_MODE);
}
/** Static method performing screen capture into PNG image format file with given fileName.
* @param rect Rectangle of screen to be captured
* @param mode image color mode
* @param fileName file name for screen capture PNG image file */
public static void captureScreen(Rectangle rect, String fileName, byte mode) {
try {
BufferedImage capture=new Robot().createScreenCapture(rect);
BufferedOutputStream file=new BufferedOutputStream(new FileOutputStream(fileName));
PNGEncoder encoder=new PNGEncoder(file, mode);
encoder.encode(capture);
} catch (AWTException awte) {
awte.printStackTrace();
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
/** Static method performing one component screen capture into PNG image format file with given fileName.
* @param comp Component to be captured
* @param fileName String image target filename */
public static void captureScreen(Component comp, String fileName) {
captureScreen(comp, fileName, GREYSCALE_MODE);
}
/** Static method performing one component screen capture into PNG image format file with given fileName.
* @param comp Component to be captured
* @param fileName String image target filename
* @param mode image color mode */
public static void captureScreen(Component comp, String fileName, byte mode) {
captureScreen(new Rectangle(comp.getLocationOnScreen(),
comp.getSize()),
fileName, mode);
}
/** Static method performing whole screen capture into PNG image format file with given fileName.
* @param fileName String image target filename */
public static void captureScreen(String fileName) {
captureScreen(fileName, GREYSCALE_MODE);
}
/** Static method performing whole screen capture into PNG image format file with given fileName.
* @param fileName String image target filename
* @param mode image color mode */
public static void captureScreen(String fileName, byte mode) {
captureScreen(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()), fileName, mode);
}
}
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