| /* |
| * Copyright (c) 2005, 2016, 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 javax.imageio.plugins.tiff.BaselineTIFFTagSet; |
| import java.io.IOException; |
| import javax.imageio.IIOException; |
| |
| /** |
| * |
| */ |
| public class TIFFRLECompressor extends TIFFFaxCompressor { |
| |
| public TIFFRLECompressor() { |
| super("CCITT RLE", BaselineTIFFTagSet.COMPRESSION_CCITT_RLE, true); |
| } |
| |
| /** |
| * Encode a row of data using Modified Huffman Compression also known as |
| * CCITT RLE (Run Lenth Encoding). |
| * |
| * @param data The row of data to compress. |
| * @param rowOffset Starting index in {@code data}. |
| * @param colOffset Bit offset within first {@code data[rowOffset]}. |
| * @param rowLength Number of bits in the row. |
| * @param compData The compressed data. |
| * |
| * @return The number of bytes saved in the compressed data array. |
| */ |
| public int encodeRLE(byte[] data, |
| int rowOffset, |
| int colOffset, |
| int rowLength, |
| byte[] compData) { |
| // |
| // Initialize bit buffer machinery. |
| // |
| initBitBuf(); |
| |
| // |
| // Run-length encode line. |
| // |
| int outIndex = |
| encode1D(data, rowOffset, colOffset, rowLength, compData, 0); |
| |
| // |
| // Flush pending bits |
| // |
| while (ndex > 0) { |
| compData[outIndex++] = (byte)(bits >>> 24); |
| bits <<= 8; |
| ndex -= 8; |
| } |
| |
| // |
| // Flip the bytes if inverse fill was requested. |
| // |
| if (inverseFill) { |
| byte[] flipTable = TIFFFaxDecompressor.flipTable; |
| for(int i = 0; i < outIndex; i++) { |
| compData[i] = flipTable[compData[i] & 0xff]; |
| } |
| } |
| |
| return outIndex; |
| } |
| |
| public int encode(byte[] b, int off, |
| int width, int height, |
| int[] bitsPerSample, |
| int scanlineStride) throws IOException { |
| if (bitsPerSample.length != 1 || bitsPerSample[0] != 1) { |
| throw new IIOException( |
| "Bits per sample must be 1 for RLE compression!"); |
| } |
| |
| // In the worst case, 2 bits of input will result in 9 bits of output, |
| // plus 2 extra bits if the row starts with black. |
| int maxBits = 9*((width + 1)/2) + 2; |
| byte[] compData = new byte[(maxBits + 7)/8]; |
| |
| int bytes = 0; |
| int rowOffset = off; |
| |
| for (int i = 0; i < height; i++) { |
| int rowBytes = encodeRLE(b, rowOffset, 0, width, compData); |
| stream.write(compData, 0, rowBytes); |
| |
| rowOffset += scanlineStride; |
| bytes += rowBytes; |
| } |
| |
| return bytes; |
| } |
| } |