001/*
002 * $RCSfile: ROIMaskGenerator.java,v $
003 * $Revision: 1.1 $
004 * $Date: 2005/02/11 05:02:22 $
005 * $State: Exp $
006 *
007 * Class:                   ROIMaskGenerator
008 *
009 * Description:             This class describes generators of ROI masks
010 *
011 *
012 *
013 * COPYRIGHT:
014 *
015 * This software module was originally developed by Raphaël Grosbois and
016 * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
017 * Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
018 * Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
019 * Centre France S.A) in the course of development of the JPEG2000
020 * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
021 * software module is an implementation of a part of the JPEG 2000
022 * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
023 * Systems AB and Canon Research Centre France S.A (collectively JJ2000
024 * Partners) agree not to assert against ISO/IEC and users of the JPEG
025 * 2000 Standard (Users) any of their rights under the copyright, not
026 * including other intellectual property rights, for this software module
027 * with respect to the usage by ISO/IEC and Users of this software module
028 * or modifications thereof for use in hardware or software products
029 * claiming conformance to the JPEG 2000 Standard. Those intending to use
030 * this software module in hardware or software products are advised that
031 * their use may infringe existing patents. The original developers of
032 * this software module, JJ2000 Partners and ISO/IEC assume no liability
033 * for use of this software module or modifications thereof. No license
034 * or right to this software module is granted for non JPEG 2000 Standard
035 * conforming products. JJ2000 Partners have full right to use this
036 * software module for his/her own purpose, assign or donate this
037 * software module to any third party and to inhibit third parties from
038 * using this software module for non JPEG 2000 Standard conforming
039 * products. This copyright notice must be included in all copies or
040 * derivative works of this software module.
041 *
042 * Copyright (c) 1999/2000 JJ2000 Partners.
043 */
044package jj2000.j2k.roi.encoder;
045
046import jj2000.j2k.image.DataBlkInt;
047import jj2000.j2k.wavelet.Subband;
048
049/**
050 * This class generates the ROI masks for the ROIScaler.It gives the scaler
051 * the ROI mask for the current code-block.
052 *
053 * <P>The values are calculated from the scaling factors of the ROIs. The
054 * values with which to scale are equal to u-umin where umin is the lowest
055 * scaling factor within the block. The umin value is sent to the entropy
056 * coder to be used for scaling the distortion values.
057 *
058 * @see RectROIMaskGenerator
059 *
060 * @see ArbROIMaskGenerator
061 *  */
062public abstract class ROIMaskGenerator{
063
064    /** Array containing the ROIs */
065    protected ROI[] rois;
066
067    /** Number of components */
068    protected int nrc;
069
070    /** Flag indicating whether a mask has been made for the current tile */
071    protected boolean tileMaskMade[];
072
073    /* Flag indicating whether there are any ROIs in this tile */
074    protected boolean roiInTile;
075
076    /**
077     * The constructor of the mask generator
078     *
079     * @param rois The ROIs in the image
080     *
081     * @param nrc The number of components
082     */
083    public ROIMaskGenerator(ROI[] rois, int nrc){
084        this.rois=rois;
085        this.nrc=nrc;
086        tileMaskMade=new boolean[nrc];
087    }
088
089    /**
090     * This function returns the ROIs in the image
091     *
092     * @return The ROIs in the image
093     */
094    public ROI[] getROIs(){
095        return rois;
096    }
097
098    /**
099     * This functions gets a DataBlk with the size of the current code-block
100     * and fills it with the ROI mask. The lowest scaling value in the mask
101     * for this code-block is returned by the function to be used for
102     * modifying the rate distortion estimations.
103     *
104     * @param db The data block that is to be filled with the mask
105     *
106     * @param sb The root of the current subband tree
107     *
108     * @param magbits The number of magnitude bits in this code-block
109     *
110     * @param c Component number
111     *
112     * @return Whether or not a mask was needed for this tile */
113    public abstract boolean getROIMask(DataBlkInt db, Subband sb,
114                                       int magbits, int c);
115
116    /**
117     * This function generates the ROI mask for the entire tile. The mask is
118     * generated for one component. This method is called once for each tile
119     * and component.
120     *
121     * @param sb The root of the subband tree used in the decomposition
122     *
123     * @param magbits The max number of magnitude bits in any code-block
124     *
125     * @param n component number
126     */
127    public abstract void makeMask(Subband sb, int magbits, int n);
128
129    /**
130     * This function is called every time the tile is changed to indicate
131     * that there is need to make a new mask
132     */
133    public void tileChanged(){
134        for(int i=0;i<nrc;i++)
135            tileMaskMade[i]=false;
136    }
137
138}