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: */
045: package com.sun.media.imageioimpl.plugins.tiff;
046:
047: import com.sun.media.imageio.plugins.tiff.BaselineTIFFTagSet;
048: import com.sun.media.imageio.plugins.tiff.TIFFCompressor;
049: import java.io.IOException;
050: import java.util.zip.Deflater;
051: import javax.imageio.ImageWriteParam;
052:
053: /**
054: * Compressor superclass for Deflate and ZLib compression.
055: */
056: public class TIFFDeflater extends TIFFCompressor {
057:
058: Deflater deflater;
059: int predictor;
060:
061: public TIFFDeflater(String compressionType,
062: int compressionTagValue, ImageWriteParam param,
063: int predictorValue) {
064: super (compressionType, compressionTagValue, true);
065:
066: this .predictor = predictorValue;
067:
068: // Set the deflate level.
069: int deflateLevel;
070: if (param != null
071: && param.getCompressionMode() == ImageWriteParam.MODE_EXPLICIT) {
072: float quality = param.getCompressionQuality();
073: deflateLevel = (int) (1 + 8 * quality);
074: } else {
075: deflateLevel = Deflater.DEFAULT_COMPRESSION;
076: }
077:
078: this .deflater = new Deflater(deflateLevel);
079: }
080:
081: public int encode(byte[] b, int off, int width, int height,
082: int[] bitsPerSample, int scanlineStride) throws IOException {
083:
084: int inputSize = height * scanlineStride;
085: int blocks = (inputSize + 32767) / 32768;
086:
087: // Worst case for Zlib deflate is input size + 5 bytes per 32k
088: // block, plus 6 header bytes
089: byte[] compData = new byte[inputSize + 5 * blocks + 6];
090:
091: int numCompressedBytes = 0;
092: if (predictor == BaselineTIFFTagSet.PREDICTOR_HORIZONTAL_DIFFERENCING) {
093: int samplesPerPixel = bitsPerSample.length;
094: int bitsPerPixel = 0;
095: for (int i = 0; i < samplesPerPixel; i++) {
096: bitsPerPixel += bitsPerSample[i];
097: }
098: int bytesPerRow = (bitsPerPixel * width + 7) / 8;
099: byte[] rowBuf = new byte[bytesPerRow];
100:
101: int maxRow = height - 1;
102: for (int i = 0; i < height; i++) {
103: // Cannot modify b[] in place as it might be a data
104: // array from the image being written so make a copy.
105: System.arraycopy(b, off, rowBuf, 0, bytesPerRow);
106: for (int j = bytesPerRow - 1; j >= samplesPerPixel; j--) {
107: rowBuf[j] -= rowBuf[j - samplesPerPixel];
108: }
109:
110: deflater.setInput(rowBuf);
111: if (i == maxRow) {
112: deflater.finish();
113: }
114:
115: int numBytes = 0;
116: while ((numBytes = deflater.deflate(compData,
117: numCompressedBytes, compData.length
118: - numCompressedBytes)) != 0) {
119: numCompressedBytes += numBytes;
120: }
121:
122: off += scanlineStride;
123: }
124: } else {
125: deflater.setInput(b, off, height * scanlineStride);
126: deflater.finish();
127:
128: numCompressedBytes = deflater.deflate(compData);
129: }
130:
131: deflater.reset();
132:
133: stream.write(compData, 0, numCompressedBytes);
134:
135: return numCompressedBytes;
136: }
137: }
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