001/*
002 * $RCSfile: TIFFDeflater.java,v $
003 *
004 * 
005 * Copyright (c) 2005 Sun Microsystems, Inc. All  Rights Reserved.
006 * 
007 * Redistribution and use in source and binary forms, with or without
008 * modification, are permitted provided that the following conditions
009 * are met: 
010 * 
011 * - Redistribution of source code must retain the above copyright 
012 *   notice, this  list of conditions and the following disclaimer.
013 * 
014 * - Redistribution in binary form must reproduce the above copyright
015 *   notice, this list of conditions and the following disclaimer in 
016 *   the documentation and/or other materials provided with the
017 *   distribution.
018 * 
019 * Neither the name of Sun Microsystems, Inc. or the names of 
020 * contributors may be used to endorse or promote products derived 
021 * from this software without specific prior written permission.
022 * 
023 * This software is provided "AS IS," without a warranty of any 
024 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
025 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, 
026 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
027 * EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL 
028 * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF 
029 * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
030 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR 
031 * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
032 * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
033 * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
034 * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
035 * POSSIBILITY OF SUCH DAMAGES. 
036 * 
037 * You acknowledge that this software is not designed or intended for 
038 * use in the design, construction, operation or maintenance of any 
039 * nuclear facility. 
040 *
041 * $Revision: 1.1 $
042 * $Date: 2005/02/11 05:01:45 $
043 * $State: Exp $
044 */
045package com.github.jaiimageio.impl.plugins.tiff;
046
047import java.io.IOException;
048import java.util.zip.Deflater;
049
050import javax.imageio.ImageWriteParam;
051
052import com.github.jaiimageio.plugins.tiff.BaselineTIFFTagSet;
053import com.github.jaiimageio.plugins.tiff.TIFFCompressor;
054
055/**
056 * Compressor superclass for Deflate and ZLib compression.
057 */
058public class TIFFDeflater extends TIFFCompressor {
059
060    Deflater deflater;
061    int predictor;
062
063    public TIFFDeflater(String compressionType,
064                        int compressionTagValue,
065                        ImageWriteParam param, 
066                        int predictorValue) {
067        super(compressionType, compressionTagValue, true);
068
069        this.predictor = predictorValue;
070
071        // Set the deflate level.
072        int deflateLevel;
073        if(param != null &&
074           param.getCompressionMode() == ImageWriteParam.MODE_EXPLICIT) {
075            float quality = param.getCompressionQuality();
076            deflateLevel = (int)(1 + 8*quality);
077        } else {
078            deflateLevel = Deflater.DEFAULT_COMPRESSION;
079        }
080
081        this.deflater = new Deflater(deflateLevel);
082    }
083
084    public int encode(byte[] b, int off,
085                      int width, int height,
086                      int[] bitsPerSample,
087                      int scanlineStride) throws IOException {
088
089        int inputSize = height*scanlineStride;
090        int blocks = (inputSize + 32767)/32768;
091
092        // Worst case for Zlib deflate is input size + 5 bytes per 32k
093        // block, plus 6 header bytes
094        byte[] compData = new byte[inputSize + 5*blocks + 6];
095
096        int numCompressedBytes = 0;
097        if(predictor == BaselineTIFFTagSet.PREDICTOR_HORIZONTAL_DIFFERENCING) {
098            int samplesPerPixel = bitsPerSample.length;
099            int bitsPerPixel = 0;
100            for (int i = 0; i < samplesPerPixel; i++) {
101                bitsPerPixel += bitsPerSample[i];
102            }
103            int bytesPerRow = (bitsPerPixel*width + 7)/8;
104            byte[] rowBuf = new byte[bytesPerRow];
105
106            int maxRow = height - 1;
107            for(int i = 0; i < height; i++) {
108                // Cannot modify b[] in place as it might be a data
109                // array from the image being written so make a copy.
110                System.arraycopy(b, off, rowBuf, 0, bytesPerRow);
111                for(int j = bytesPerRow - 1; j >= samplesPerPixel; j--) {
112                    rowBuf[j] -= rowBuf[j - samplesPerPixel];
113                }
114
115                deflater.setInput(rowBuf);
116                if(i == maxRow) {
117                    deflater.finish();
118                }
119
120                int numBytes = 0;
121                while((numBytes = deflater.deflate(compData,
122                                                   numCompressedBytes,
123                                                   compData.length -
124                                                   numCompressedBytes)) != 0) {
125                    numCompressedBytes += numBytes;
126                }
127
128                off += scanlineStride;
129            }
130        } else {
131            deflater.setInput(b, off, height*scanlineStride);
132            deflater.finish();
133
134            numCompressedBytes = deflater.deflate(compData);
135        }
136
137        deflater.reset();
138
139        stream.write(compData, 0, numCompressedBytes);
140
141        return numCompressedBytes;
142    }
143    
144    public void dispose() {
145      if (deflater != null) {
146        deflater.end();
147        deflater = null;
148      }
149      super.dispose();
150    }
151}