META-INF.modules.java.desktop.classes.com.sun.imageio.plugins.tiff.TIFFLZWCompressor Maven / Gradle / Ivy
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/*
* Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.sun.imageio.plugins.tiff;
import com.sun.imageio.plugins.common.LZWCompressor;
import java.io.IOException;
import javax.imageio.stream.ImageOutputStream;
import javax.imageio.plugins.tiff.BaselineTIFFTagSet;
/**
* LZW Compressor.
*/
public class TIFFLZWCompressor extends TIFFCompressor {
private final int predictor;
public TIFFLZWCompressor(int predictorValue) {
super("LZW", BaselineTIFFTagSet.COMPRESSION_LZW, true);
this.predictor = predictorValue;
}
public void setStream(ImageOutputStream stream) {
super.setStream(stream);
}
public int encode(byte[] b, int off,
int width, int height,
int[] bitsPerSample,
int scanlineStride) throws IOException {
LZWCompressor lzwCompressor = new LZWCompressor(stream, 8, true);
int samplesPerPixel = bitsPerSample.length;
int bitsPerPixel = 0;
for (int i = 0; i < samplesPerPixel; i++) {
bitsPerPixel += bitsPerSample[i];
}
int bytesPerRow = (bitsPerPixel*width + 7)/8;
long initialStreamPosition = stream.getStreamPosition();
boolean usePredictor =
predictor == BaselineTIFFTagSet.PREDICTOR_HORIZONTAL_DIFFERENCING;
if(bytesPerRow == scanlineStride && !usePredictor) {
lzwCompressor.compress(b, off, bytesPerRow*height);
} else {
byte[] rowBuf = usePredictor ? new byte[bytesPerRow] : null;
for(int i = 0; i < height; i++) {
if(usePredictor) {
// Cannot modify b[] in place as it might be a data
// array from the image being written so make a copy.
System.arraycopy(b, off, rowBuf, 0, bytesPerRow);
for(int j = bytesPerRow - 1; j >= samplesPerPixel; j--) {
rowBuf[j] -= rowBuf[j - samplesPerPixel];
}
lzwCompressor.compress(rowBuf, 0, bytesPerRow);
} else {
lzwCompressor.compress(b, off, bytesPerRow);
}
off += scanlineStride;
}
}
lzwCompressor.flush();
int bytesWritten =
(int)(stream.getStreamPosition() - initialStreamPosition);
return bytesWritten;
}
}