001/*
002 * $RCSfile: SubbandROIMask.java,v $
003 * $Revision: 1.1 $
004 * $Date: 2005/02/11 05:02:24 $
005 * $State: Exp $
006 *
007 * Class:                   ROI
008 *
009 * Description:             This class describes the ROI mask for a subband
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
046
047/**
048 * This abstract class describes the ROI mask for a single subband. Each
049 * object of the class contains the mask for a particular subband and also has
050 * references to the masks of the children subbands of the subband
051 * corresponding to this mask.  */
052public abstract class SubbandROIMask{
053
054    /** The subband masks of the child LL */
055    protected SubbandROIMask ll;
056
057    /** The subband masks of the child LH */
058    protected SubbandROIMask lh;
059
060    /** The subband masks of the child HL */
061    protected SubbandROIMask hl;
062
063    /** The subband masks of the child HH */
064    protected SubbandROIMask hh;
065
066    /** Flag indicating whether this subband mask is a node or not */
067    protected boolean isNode;
068
069    /** Horizontal uper-left coordinate of the subband mask */
070    public int ulx;
071
072    /** Vertical uper-left coordinate of the subband mask */
073    public int uly;
074
075    /** Width of the subband mask */
076    public int w;
077
078    /** Height of the subband mask */
079    public int h;
080
081    /**
082     * The constructor of the SubbandROIMask takes the dimensions of the
083     * subband as parameters
084     *
085     * @param ulx The upper left x coordinate of corresponding subband
086     *
087     * @param uly The upper left y coordinate of corresponding subband
088     *
089     * @param w The width of corresponding subband
090     *
091     * @param h The height of corresponding subband
092     * */
093    public SubbandROIMask(int ulx, int uly, int w, int h){
094        this.ulx=ulx;
095        this.uly=uly;
096        this.w=w;
097        this.h=h;
098    }
099
100    /**
101     * Returns a reference to the Subband mask element to which the specified
102     * point belongs. The specified point must be inside this (i.e. the one
103     * defined by this object) subband mask. This method searches through the
104     * tree.
105     *
106     * @param x horizontal coordinate of the specified point.
107     *
108     * @param y horizontal coordinate of the specified point.
109     * */
110    public SubbandROIMask getSubbandRectROIMask(int x, int y) {
111        SubbandROIMask cur,hhs;
112
113        // Check that we are inside this subband
114        if (x < ulx || y < uly || x >= ulx+w || y >= uly+h) {
115            throw new IllegalArgumentException();
116        }
117
118        cur = this;
119        while (cur.isNode) {
120            hhs = cur.hh;
121            // While we are still at a node -> continue
122            if (x < hhs.ulx) {
123                // Is the result of horizontal low-pass
124                if (y < hhs.uly) {
125                    // Vertical low-pass
126                    cur = cur.ll;
127                }
128                else {
129                    // Vertical high-pass
130                    cur = cur.lh;
131                }
132            }
133            else {
134                // Is the result of horizontal high-pass
135                if (y < hhs.uly) {
136                    // Vertical low-pass
137                    cur = cur.hl;
138                }
139                else {
140                    // Vertical high-pass
141                    cur = cur.hh;
142                }
143            }
144        }
145        return cur;
146    }
147}
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