?? imgdatajoiner.java
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/* * CVS identifier: * * $Id: ImgDataJoiner.java,v 1.1.1.1 2002/07/22 09:26:50 grosbois Exp $ * * Class: ImgDataJoiner * * Description: Get ImgData from different sources * * * * COPYRIGHT: * * This software module was originally developed by Rapha雔 Grosbois and * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel * Askel鰂 (Ericsson Radio Systems AB); and Bertrand Berthelot, David * Bouchard, F閘ix Henry, Gerard Mozelle and Patrice Onno (Canon Research * Centre France S.A) in the course of development of the JPEG2000 * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This * software module is an implementation of a part of the JPEG 2000 * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio * Systems AB and Canon Research Centre France S.A (collectively JJ2000 * Partners) agree not to assert against ISO/IEC and users of the JPEG * 2000 Standard (Users) any of their rights under the copyright, not * including other intellectual property rights, for this software module * with respect to the usage by ISO/IEC and Users of this software module * or modifications thereof for use in hardware or software products * claiming conformance to the JPEG 2000 Standard. Those intending to use * this software module in hardware or software products are advised that * their use may infringe existing patents. The original developers of * this software module, JJ2000 Partners and ISO/IEC assume no liability * for use of this software module or modifications thereof. No license * or right to this software module is granted for non JPEG 2000 Standard * conforming products. JJ2000 Partners have full right to use this * software module for his/her own purpose, assign or donate this * software module to any third party and to inhibit third parties from * using this software module for non JPEG 2000 Standard conforming * products. This copyright notice must be included in all copies or * derivative works of this software module. * * Copyright (c) 1999/2000 JJ2000 Partners. * */package jj2000.j2k.image;import jj2000.j2k.*;/** * This class implements the ImgData interface and allows to obtain data from * different sources. Here, one source is represented by an ImgData and a * component index. The typical use of this class is when the encoder needs * different components (Red, Green, Blue, alpha, ...) from different input * files (i.e. from different ImgReader objects). * * <p>All input ImgData must not be tiled (i.e. must have only 1 tile) and the * image origin must be the canvas origin. The different inputs can have * different dimensions though (this will lead to different subsampling * factors for each component).</p> * * <p>The input ImgData and component index list must be defined when * constructing this class and can not be modified later.</p> * * @see ImgData * @see jj2000.j2k.image.input.ImgReader * */public class ImgDataJoiner implements BlkImgDataSrc { /** The width of the image */ private int w; /** The height of the image */ private int h; /** The number of components in the image */ private int nc; /** The list of input ImgData */ private BlkImgDataSrc[] imageData; /** The component index associated with each ImgData */ private int[] compIdx; /** The subsampling factor along the horizontal direction, for every * component */ private int[] subsX; /** The subsampling factor along the vertical direction, for every * component */ private int[] subsY; /** * Class constructor. Each input BlkImgDataSrc and its component index * must appear in the order wanted for the output components.<br> * * <u>Example:</u> Reading R,G,B components from 3 PGM files.<br> * <tt> * BlkImgDataSrc[] idList = <br> * {<br> * new ImgReaderPGM(new BEBufferedRandomAccessFile("R.pgm", "r")),<br> * new ImgReaderPGM(new BEBufferedRandomAccessFile("G.pgm", "r")),<br> * new ImgReaderPGM(new BEBufferedRandomAccessFile("B.pgm", "r"))<br> * };<br> * int[] compIdx = {0,0,0};<br> * ImgDataJoiner idj = new ImgDataJoiner(idList, compIdx); * </tt> * * <p>Of course, the 2 arrays must have the same length (This length is * the number of output components). The image width and height are * definded to be the maximum values of all the input ImgData. * * @param imD The list of input BlkImgDataSrc in an array. * * @param cIdx The component index associated with each ImgData. * */ public ImgDataJoiner(BlkImgDataSrc[] imD, int[] cIdx){ int i; int maxW, maxH; // Initializes imageData = imD; compIdx = cIdx; if(imageData.length != compIdx.length) throw new IllegalArgumentException("imD and cIdx must have the"+ " same length"); nc = imD.length; subsX = new int[nc]; subsY = new int[nc]; // Check that no source is tiled and that the image origin is at the // canvas origin. for(i=0; i<nc; i++) { if (imD[i].getNumTiles() != 1 || imD[i].getCompULX(cIdx[i])!=0 || imD[i].getCompULY(cIdx[i])!=0) { throw new IllegalArgumentException("All input components must, "+ "not use tiles and must "+ "have "+ "the origin at the canvas "+ "origin"); } } // Guess component subsampling factors based on the fact that the // ceil() operation relates the reference grid size to the component's // size, through the subsampling factor. // Mhhh, difficult problem. For now just assume that one of the // subsampling factors is always 1 and that the component width is // always larger than its subsampling factor, which covers most of the // cases. We check the correctness of the solution once found to chek // out hypothesis. // Look for max width and height. maxW = 0; maxH = 0; for(i=0; i<nc; i++) { if(imD[i].getCompImgWidth(cIdx[i]) > maxW) maxW = imD[i].getCompImgWidth(cIdx[i]); if(imD[i].getCompImgHeight(cIdx[i]) > maxH) maxH = imD[i].getCompImgHeight(cIdx[i]); } // Set the image width and height as the maximum ones w = maxW; h = maxH; // Now get the sumsampling factors and check the subsampling factors, // just to see if above hypothesis were correct. for (i=0; i<nc; i++) { // This calculation only holds if the subsampling factor is less // than the component width subsX[i] = (maxW + imD[i].getCompImgWidth(cIdx[i])-1) / imD[i].getCompImgWidth(cIdx[i]); subsY[i] = (maxH + imD[i].getCompImgHeight(cIdx[i])-1) / imD[i].getCompImgHeight(cIdx[i]); if ((maxW+subsX[i]-1)/subsX[i] != imD[i].getCompImgWidth(cIdx[i]) || (maxH+subsY[i]-1)/subsY[i] != imD[i].getCompImgHeight(cIdx[i])) { throw new Error("Can not compute component subsampling "+ "factors: strange subsampling."); } } } /** * Returns the overall width of the current tile in pixels. This is the * tile's width without accounting for any component subsampling. * * @return The total current tile's width in pixels. * */ public int getTileWidth(){ return w; } /** * Returns the overall height of the current tile in pixels. This is the * tile's height without accounting for any component subsampling. * * @return The total current tile's height in pixels. * */ public int getTileHeight(){ return h; } /** Returns the nominal tiles width */ public int getNomTileWidth() { return w; } /** Returns the nominal tiles height */ public int getNomTileHeight() { return h; } /** * Returns the overall width of the image in pixels. This is the image's * width without accounting for any component subsampling or tiling. * * @return The total image's width in pixels. * */ public int getImgWidth(){ return w; } /** * Returns the overall height of the image in pixels. This is the image's * height without accounting for any component subsampling or tiling. * * @return The total image's height in pixels. * */ public int getImgHeight(){ return h; } /** * Returns the number of components in the image. * * @return The number of components in the image. * */ public int getNumComps(){ return nc; } /** * Returns the component subsampling factor in the horizontal direction, * for the specified component. This is, approximately, the ratio of * dimensions between the reference grid and the component itself, see the * 'ImgData' interface desription for details. * * @param c The index of the component (between 0 and N-1) * * @return The horizontal subsampling factor of component 'c' * * @see ImgData * */ public int getCompSubsX(int c) { return subsX[c]; } /** * Returns the component subsampling factor in the vertical direction, for * the specified component. This is, approximately, the ratio of * dimensions between the reference grid and the component itself, see the * 'ImgData' interface desription for details. * * @param c The index of the component (between 0 and N-1) * * @return The vertical subsampling factor of component 'c' * * @see ImgData * */ public int getCompSubsY(int c) { return subsY[c]; } /** * Returns the width in pixels of the specified tile-component * * @param t Tile index * * @param c The index of the component, from 0 to N-1. * * @return The width in pixels of component <tt>c</tt> in tile<tt>t</tt>. * */ public int getTileCompWidth(int t,int c){ return imageData[c].getTileCompWidth(t,compIdx[c]); } /** * Returns the height in pixels of the specified tile-component. * * @param t The tile index. * * @param c The index of the component, from 0 to N-1. * * @return The height in pixels of component <tt>c</tt> in the current * tile. * */ public int getTileCompHeight(int t,int c){ return imageData[c].getTileCompHeight(t,compIdx[c]); }
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