git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@4253 6c8d7289-2bf4-0310-a012-ef5d649a1542pull/1/head
orbiter
17 years ago
parent
f243e338cf
commit
e22014dc83
@ -1,544 +0,0 @@
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/**
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* PngEncoder takes a Java Image object and creates a byte string which can be saved as a PNG file.
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* The Image is presumed to use the DirectColorModel.
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*
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* Thanks to Jay Denny at KeyPoint Software
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* http://www.keypoint.com/
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* who let me develop this code on company time.
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*
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* You may contact me with (probably very-much-needed) improvements,
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* comments, and bug fixes at:
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*
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* david@catcode.com
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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* A copy of the GNU LGPL may be found at
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* http://www.gnu.org/copyleft/lesser.html,
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*
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* @author J. David Eisenberg
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* @version 1.4, 31 March 2000
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*
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* $LastChangedDate$
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* $LastChangedRevision$
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* $LastChangedBy$
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*/
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/*
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* this file was taken from
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* http://chem.sis.nlm.nih.gov/chemidplus/applet/chemaxon/marvin/help/PngEncoder.java.txt
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* and modified by Michael Peter Christen, Frankfurt, 2005
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* to work with ImagePainter Objects instead of awt.image Objetcs
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* this avoids using any awt routines
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*/
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package de.anomic.ymage;
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import java.io.ByteArrayOutputStream;
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import java.io.IOException;
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import java.util.zip.CRC32;
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import java.util.zip.Deflater;
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import java.util.zip.DeflaterOutputStream;
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public class ymagePNGEncoderJDE extends Object
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{
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/** Constants for filters */
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public static final int FILTER_NONE = 0;
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public static final int FILTER_SUB = 1;
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public static final int FILTER_UP = 2;
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public static final int FILTER_LAST = 2;
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protected byte[] pngBytes;
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protected byte[] priorRow;
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protected byte[] leftBytes;
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protected ymageMatrix matrix;
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protected int width, height;
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protected int bytePos, maxPos;
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protected int hdrPos, dataPos, endPos;
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protected CRC32 crc = new CRC32();
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protected long crcValue;
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protected boolean encodeAlpha;
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protected int filter;
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protected int bytesPerPixel;
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protected int compressionLevel;
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/**
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* Class constructor specifying Image source to encode, whether to encode alpha, filter to use, and compression level.
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*
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* @param image A Java Image object
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* @param encodeAlpha Encode the alpha channel? false=no; true=yes
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* @param whichFilter 0=none, 1=sub, 2=up
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* @param compLevel 0..9
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* @see java.awt.Image
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*/
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public ymagePNGEncoderJDE(ymageMatrix matrix, int whichFilter, int compLevel)
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{
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this.matrix = matrix;
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this.encodeAlpha = false;
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setFilter( whichFilter );
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if (compLevel >=0 && compLevel <=9)
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{
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this.compressionLevel = compLevel;
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}
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}
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/**
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* Creates an array of bytes that is the PNG equivalent of the current image, specifying whether to encode alpha or not.
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*
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* @param encodeAlpha boolean false=no alpha, true=encode alpha
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* @return an array of bytes, or null if there was a problem
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*/
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public byte[] pngEncode()
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{
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byte[] pngIdBytes = { -119, 80, 78, 71, 13, 10, 26, 10 };
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if (matrix == null)
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{
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return null;
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}
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width = matrix.getWidth();
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height = matrix.getHeight();
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/*
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* start with an array that is big enough to hold all the pixels
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* (plus filter bytes), and an extra 200 bytes for header info
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*/
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pngBytes = new byte[((width+1) * height * 3) + 200];
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/*
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* keep track of largest byte written to the array
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*/
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maxPos = 0;
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bytePos = writeBytes( pngIdBytes, 0 );
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hdrPos = bytePos;
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writeHeader();
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dataPos = bytePos;
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if (writeImageData())
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{
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writeEnd();
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pngBytes = resizeByteArray( pngBytes, maxPos );
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}
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else
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{
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pngBytes = null;
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}
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return pngBytes;
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}
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/**
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* Set the alpha encoding on or off.
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*
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* @param encodeAlpha false=no, true=yes
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*/
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public void setEncodeAlpha( boolean encodeAlpha )
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{
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this.encodeAlpha = encodeAlpha;
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}
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/**
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* Retrieve alpha encoding status.
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*
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* @return boolean false=no, true=yes
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*/
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public boolean getEncodeAlpha()
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{
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return encodeAlpha;
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}
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/**
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* Set the filter to use
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*
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* @param whichFilter from constant list
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*/
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public void setFilter( int whichFilter )
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{
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this.filter = FILTER_NONE;
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if ( whichFilter <= FILTER_LAST )
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{
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this.filter = whichFilter;
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}
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}
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/**
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* Retrieve filtering scheme
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*
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* @return int (see constant list)
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*/
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public int getFilter()
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{
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return filter;
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}
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/**
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* Set the compression level to use
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*
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* @param level 0 through 9
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*/
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public void setCompressionLevel( int level )
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{
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if ( level >= 0 && level <= 9)
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{
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this.compressionLevel = level;
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}
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}
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/**
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* Retrieve compression level
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*
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* @return int in range 0-9
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*/
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public int getCompressionLevel()
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{
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return compressionLevel;
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}
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/**
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* Increase or decrease the length of a byte array.
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*
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* @param array The original array.
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* @param newLength The length you wish the new array to have.
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* @return Array of newly desired length. If shorter than the
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* original, the trailing elements are truncated.
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*/
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protected byte[] resizeByteArray( byte[] array, int newLength )
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{
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byte[] newArray = new byte[newLength];
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int oldLength = array.length;
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System.arraycopy( array, 0, newArray, 0,
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Math.min( oldLength, newLength ) );
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return newArray;
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}
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/**
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* Write an array of bytes into the pngBytes array.
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* Note: This routine has the side effect of updating
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* maxPos, the largest element written in the array.
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* The array is resized by 1000 bytes or the length
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* of the data to be written, whichever is larger.
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*
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* @param data The data to be written into pngBytes.
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* @param offset The starting point to write to.
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* @return The next place to be written to in the pngBytes array.
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*/
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protected int writeBytes( byte[] data, int offset )
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{
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maxPos = Math.max( maxPos, offset + data.length );
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if (data.length + offset > pngBytes.length)
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{
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pngBytes = resizeByteArray( pngBytes, pngBytes.length +
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Math.max( 1000, data.length ) );
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}
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System.arraycopy( data, 0, pngBytes, offset, data.length );
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return offset + data.length;
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}
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/**
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* Write an array of bytes into the pngBytes array, specifying number of bytes to write.
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* Note: This routine has the side effect of updating
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* maxPos, the largest element written in the array.
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* The array is resized by 1000 bytes or the length
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* of the data to be written, whichever is larger.
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*
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* @param data The data to be written into pngBytes.
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* @param nBytes The number of bytes to be written.
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* @param offset The starting point to write to.
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* @return The next place to be written to in the pngBytes array.
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*/
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protected int writeBytes( byte[] data, int nBytes, int offset )
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{
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maxPos = Math.max( maxPos, offset + nBytes );
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if (nBytes + offset > pngBytes.length)
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{
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pngBytes = resizeByteArray( pngBytes, pngBytes.length +
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Math.max( 1000, nBytes ) );
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}
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System.arraycopy( data, 0, pngBytes, offset, nBytes );
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return offset + nBytes;
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}
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/**
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* Write a two-byte integer into the pngBytes array at a given position.
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*
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* @param n The integer to be written into pngBytes.
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* @param offset The starting point to write to.
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* @return The next place to be written to in the pngBytes array.
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*/
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protected int writeInt2( int n, int offset )
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{
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byte[] temp = { (byte)((n >> 8) & 0xff),
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(byte) (n & 0xff) };
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return writeBytes( temp, offset );
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}
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/**
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* Write a four-byte integer into the pngBytes array at a given position.
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*
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* @param n The integer to be written into pngBytes.
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* @param offset The starting point to write to.
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* @return The next place to be written to in the pngBytes array.
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*/
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protected int writeInt4( int n, int offset )
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{
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byte[] temp = { (byte)((n >> 24) & 0xff),
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(byte) ((n >> 16) & 0xff ),
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(byte) ((n >> 8) & 0xff ),
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(byte) ( n & 0xff ) };
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return writeBytes( temp, offset );
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}
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/**
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* Write a single byte into the pngBytes array at a given position.
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*
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* @param n The integer to be written into pngBytes.
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* @param offset The starting point to write to.
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* @return The next place to be written to in the pngBytes array.
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*/
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protected int writeByte( int b, int offset )
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{
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byte[] temp = { (byte) b };
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return writeBytes( temp, offset );
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}
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/**
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* Write a string into the pngBytes array at a given position.
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* This uses the getBytes method, so the encoding used will
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* be its default.
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*
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* @param n The integer to be written into pngBytes.
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* @param offset The starting point to write to.
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* @return The next place to be written to in the pngBytes array.
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* @see java.lang.String#getBytes()
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*/
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protected int writeString( String s, int offset )
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{
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return writeBytes( s.getBytes(), offset );
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}
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/**
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* Write a PNG "IHDR" chunk into the pngBytes array.
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*/
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protected void writeHeader()
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{
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int startPos;
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startPos = bytePos = writeInt4( 13, bytePos );
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bytePos = writeString( "IHDR", bytePos );
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width = matrix.getWidth();
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height = matrix.getHeight();
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bytePos = writeInt4( width, bytePos );
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bytePos = writeInt4( height, bytePos );
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bytePos = writeByte( 8, bytePos ); // bit depth
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bytePos = writeByte( (encodeAlpha) ? 6 : 2, bytePos ); // direct model
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bytePos = writeByte( 0, bytePos ); // compression method
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bytePos = writeByte( 0, bytePos ); // filter method
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bytePos = writeByte( 0, bytePos ); // no interlace
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crc.reset();
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crc.update( pngBytes, startPos, bytePos-startPos );
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crcValue = crc.getValue();
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bytePos = writeInt4( (int) crcValue, bytePos );
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}
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/**
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* Perform "sub" filtering on the given row.
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* Uses temporary array leftBytes to store the original values
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* of the previous pixels. The array is 16 bytes long, which
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* will easily hold two-byte samples plus two-byte alpha.
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*
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* @param pixels The array holding the scan lines being built
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* @param startPos Starting position within pixels of bytes to be filtered.
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* @param width Width of a scanline in pixels.
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*/
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protected void filterSub( byte[] pixels, int startPos, int width )
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{
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int i;
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int offset = bytesPerPixel;
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int actualStart = startPos + offset;
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int nBytes = width * bytesPerPixel;
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int leftInsert = offset;
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int leftExtract = 0;
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for (i=actualStart; i < startPos + nBytes; i++)
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{
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leftBytes[leftInsert] = pixels[i];
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pixels[i] = (byte) ((pixels[i] - leftBytes[leftExtract]) % 256);
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leftInsert = (leftInsert+1) % 0x0f;
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leftExtract = (leftExtract + 1) % 0x0f;
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}
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}
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/**
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* Perform "up" filtering on the given row.
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* Side effect: refills the prior row with current row
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*
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* @param pixels The array holding the scan lines being built
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* @param startPos Starting position within pixels of bytes to be filtered.
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* @param width Width of a scanline in pixels.
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*/
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protected void filterUp( byte[] pixels, int startPos, int width )
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{
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int i, nBytes;
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byte current_byte;
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nBytes = width * bytesPerPixel;
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for (i=0; i < nBytes; i++)
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{
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current_byte = pixels[startPos + i];
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pixels[startPos + i] = (byte) ((pixels[startPos + i] - priorRow[i]) % 256);
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priorRow[i] = current_byte;
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}
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}
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/**
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* Write the image data into the pngBytes array.
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* This will write one or more PNG "IDAT" chunks. In order
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* to conserve memory, this method grabs as many rows as will
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* fit into 32K bytes, or the whole image; whichever is less.
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*
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*
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* @return true if no errors; false if error grabbing pixels
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*/
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protected boolean writeImageData()
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{
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int rowsLeft = height; // number of rows remaining to write
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int startRow = 0; // starting row to process this time through
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int nRows; // how many rows to grab at a time
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byte[] scanLines; // the scan lines to be compressed
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int scanPos; // where we are in the scan lines
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int startPos; // where this line's actual pixels start (used for filtering)
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byte[] compressedLines; // the resultant compressed lines
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int nCompressed; // how big is the compressed area?
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//int depth; // color depth ( handle only 8 or 32 )
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bytesPerPixel = (encodeAlpha) ? 4 : 3;
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Deflater scrunch = new Deflater( compressionLevel );
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ByteArrayOutputStream outBytes =
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new ByteArrayOutputStream(1024);
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DeflaterOutputStream compBytes =
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new DeflaterOutputStream( outBytes, scrunch );
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try
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{
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while (rowsLeft > 0)
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{
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nRows = Math.min( 32767 / (width*(bytesPerPixel+1)), rowsLeft );
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// nRows = rowsLeft;
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/*
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* Create a data chunk. scanLines adds "nRows" for
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* the filter bytes.
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*/
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scanLines = new byte[width * nRows * bytesPerPixel + nRows];
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if (filter == FILTER_SUB)
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{
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leftBytes = new byte[16];
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}
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if (filter == FILTER_UP)
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{
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priorRow = new byte[width*bytesPerPixel];
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}
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scanPos = 0;
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startPos = 1;
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int[] pixel;
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//matrix.getColorMode(true);
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for (int i=0; i<width*nRows; i++)
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{
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if (i % width == 0)
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{
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scanLines[scanPos++] = (byte) filter;
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startPos = scanPos;
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}
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pixel = matrix.getColor(i % width, i / width);
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scanLines[scanPos++] = (byte) pixel[0]; // red
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scanLines[scanPos++] = (byte) pixel[1]; // green
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scanLines[scanPos++] = (byte) pixel[2]; // blue
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if (encodeAlpha)
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{
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//scanLines[scanPos++] = (byte) ((pixels[i] >> 24) & 0xff );
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}
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if ((i % width == width-1) && (filter != FILTER_NONE))
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{
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if (filter == FILTER_SUB)
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{
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filterSub( scanLines, startPos, width );
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}
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if (filter == FILTER_UP)
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{
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filterUp( scanLines, startPos, width );
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}
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}
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}
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/*
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* Write these lines to the output area
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*/
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compBytes.write( scanLines, 0, scanPos );
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startRow += nRows;
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rowsLeft -= nRows;
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}
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compBytes.close();
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/*
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* Write the compressed bytes
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*/
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compressedLines = outBytes.toByteArray();
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nCompressed = compressedLines.length;
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crc.reset();
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bytePos = writeInt4( nCompressed, bytePos );
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bytePos = writeString("IDAT", bytePos );
|
||||
crc.update("IDAT".getBytes());
|
||||
bytePos = writeBytes( compressedLines, nCompressed, bytePos );
|
||||
crc.update( compressedLines, 0, nCompressed );
|
||||
|
||||
crcValue = crc.getValue();
|
||||
bytePos = writeInt4( (int) crcValue, bytePos );
|
||||
scrunch.finish();
|
||||
return true;
|
||||
}
|
||||
catch (IOException e)
|
||||
{
|
||||
System.err.println( e.toString());
|
||||
return false;
|
||||
} finally {
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Write a PNG "IEND" chunk into the pngBytes array.
|
||||
*/
|
||||
protected void writeEnd()
|
||||
{
|
||||
bytePos = writeInt4( 0, bytePos );
|
||||
bytePos = writeString( "IEND", bytePos );
|
||||
crc.reset();
|
||||
crc.update("IEND".getBytes());
|
||||
crcValue = crc.getValue();
|
||||
bytePos = writeInt4( (int) crcValue, bytePos );
|
||||
}
|
||||
}
|
||||
Loading…
Reference in new issue