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.*;
047import jj2000.j2k.quantization.*;
048import jj2000.j2k.wavelet.*;
049import jj2000.j2k.wavelet.analysis.*;
050import jj2000.j2k.codestream.writer.*;
051import jj2000.j2k.util.*;
052import jj2000.j2k.roi.*;
053
054/**
055 * This class generates the ROI masks for the ROIScaler.It gives the scaler
056 * the ROI mask for the current code-block.
057 *
058 * <P>The values are calculated from the scaling factors of the ROIs. The
059 * values with which to scale are equal to u-umin where umin is the lowest
060 * scaling factor within the block. The umin value is sent to the entropy
061 * coder to be used for scaling the distortion values.
062 *
063 * @see RectROIMaskGenerator
064 *
065 * @see ArbROIMaskGenerator
066 *  */
067public abstract class ROIMaskGenerator{
068
069    /** Array containing the ROIs */
070    protected ROI[] rois;
071
072    /** Number of components */
073    protected int nrc;
074
075    /** Flag indicating whether a mask has been made for the current tile */
076    protected boolean tileMaskMade[];
077
078    /* Flag indicating whether there are any ROIs in this tile */
079    protected boolean roiInTile;
080
081    /**
082     * The constructor of the mask generator
083     *
084     * @param rois The ROIs in the image
085     *
086     * @param nrc The number of components
087     */
088    public ROIMaskGenerator(ROI[] rois, int nrc){
089        this.rois=rois;
090        this.nrc=nrc;
091        tileMaskMade=new boolean[nrc];
092    }
093
094    /**
095     * This function returns the ROIs in the image
096     *
097     * @return The ROIs in the image
098     */
099    public ROI[] getROIs(){
100        return rois;
101    }
102
103    /**
104     * This functions gets a DataBlk with the size of the current code-block
105     * and fills it with the ROI mask. The lowest scaling value in the mask
106     * for this code-block is returned by the function to be used for
107     * modifying the rate distortion estimations.
108     *
109     * @param db The data block that is to be filled with the mask
110     *
111     * @param sb The root of the current subband tree
112     *
113     * @param magbits The number of magnitude bits in this code-block
114     *
115     * @param c Component number
116     *
117     * @return Whether or not a mask was needed for this tile */
118    public abstract boolean getROIMask(DataBlkInt db, Subband sb,
119                                       int magbits, int c);
120
121    /**
122     * This function generates the ROI mask for the entire tile. The mask is
123     * generated for one component. This method is called once for each tile
124     * and component.
125     *
126     * @param sb The root of the subband tree used in the decomposition
127     *
128     * @param magbits The max number of magnitude bits in any code-block
129     *
130     * @param n component number
131     */
132    public abstract void makeMask(Subband sb, int magbits, int n);
133
134    /**
135     * This function is called every time the tile is changed to indicate
136     * that there is need to make a new mask
137     */
138    public void tileChanged(){
139        for(int i=0;i<nrc;i++)
140            tileMaskMade[i]=false;
141    }
142
143}