88 lines
2.6 KiB
Java
88 lines
2.6 KiB
Java
//******************************************************************************
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//
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// File: IHDRChunk.java
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// Package: edu.rit.image.png
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// Unit: Class edu.rit.image.png.IHDRChunk
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//
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// This Java source file is copyright (C) 2013 by Alan Kaminsky. All rights
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// reserved. For further information, contact the author, Alan Kaminsky, at
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// ark@cs.rit.edu.
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//
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// This Java source file is part of the Parallel Java 2 Library ("PJ2"). PJ2 is
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// free software; you can redistribute it and/or modify it under the terms of
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// the GNU General Public License as published by the Free Software Foundation;
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// either version 3 of the License, or (at your option) any later version.
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//
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// PJ2 is distributed in the hope that it will be useful, but WITHOUT ANY
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// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
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// A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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//
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// A copy of the GNU General Public License is provided in the file gpl.txt. You
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// may also obtain a copy of the GNU General Public License on the World Wide
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// Web at http://www.gnu.org/licenses/gpl.html.
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//
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//******************************************************************************
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package edu.rit.image.png;
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import edu.rit.util.Packing;
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/**
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* Class IHDRChunk provides an image header chunk stored in a PNG file.
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*
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* @author Alan Kaminsky
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* @version 22-May-2013
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*/
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public class IHDRChunk
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extends Chunk
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{
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// Exported constructors.
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/**
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* Construct a new uninitialized IHDR chunk. This constructor is for use
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* only by object deserialization.
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*/
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public IHDRChunk()
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{
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super();
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}
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/**
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* Construct a new IHDR chunk. The following fields are fixed: compression
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* method = 0 (deflate), filter method = 0 (adaptive filtering), interlace
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* method = 0 (no interlacing).
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*
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* @param width Image width in pixels.
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* @param height Image height in pixels.
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* @param bitDepth Sample bit depth.
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* @param colorType Color type.
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*/
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public IHDRChunk
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(int width,
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int height,
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int bitDepth,
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int colorType)
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{
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super (0x49484452, getData (width, height, bitDepth, colorType));
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}
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private static byte[] getData
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(int width,
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int height,
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int bitDepth,
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int colorType)
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{
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byte[] data = new byte [13];
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Packing.unpackIntBigEndian (width, data, 0); // Width
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Packing.unpackIntBigEndian (height, data, 4); // Height
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data[8] = (byte) bitDepth; // Bit depth
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data[9] = (byte) colorType; // Color type
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data[10] = (byte) 0; // Compression method
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data[11] = (byte) 0; // Filter method
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data[12] = (byte) 0; // Interlace method
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return data;
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}
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}
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