/* * CVS identifier: * * $Id: Subband.java,v 1.1.1.1 2002/07/22 09:26:54 grosbois Exp $ * * Class:                   Subband * * Description:             Asbtract element for a tree strcuture for *                          a description of subbands. * * * * 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.wavelet;import jj2000.j2k.image.*;/** * This abstract class represents a subband in a bidirectional tree structure * that describes the subband decomposition for a wavelet transform. This * class is implemented by the SubbandAn and SubbandSyn classes, which are for * the analysis and synthesis sides respectively. * * <p>The element can be either a node or a leaf of the tree. If it is a node, * it has 4 descendants (LL, HL, LH and HH). If it is a leaf, it has no * descendant.</p> * * <p>The tree is bidirectional. Each element in the tree structure has a * "parent", which is the subband from which the element was obtained by * decomposition. The only exception is the root element which, for obvious * reasons, has no parent (i.e. it is null).</p> * * @see jj2000.j2k.wavelet.analysis.SubbandAn * @see jj2000.j2k.wavelet.synthesis.SubbandSyn * */public abstract class Subband {    /** The ID for the LL orientation */    public final static int WT_ORIENT_LL = 0;    /** The ID for the HL (horizontal high-pass) orientation */    public final static int WT_ORIENT_HL = 1;    /** The ID for the LH (vertical high-pass) orientation */    public final static int WT_ORIENT_LH = 2;    /** The ID for the HH orientation */    public final static int WT_ORIENT_HH = 3;    /** True if it is a node in the tree, false if it is a leaf. */    public boolean isNode;    /** The orientation of this subband (WT_ORIENT_LL, WT_ORIENT_HL,     * WT_ORIENT_LH, WT_ORIENT_HH). */    public int orientation;    /** The level in the tree to which this subband belongs, which is the     * number of performed wavelet decompositions to get this subband. It is 0     * for the top-level (i.e. root) node. */    public int level;    /** The resolution level to which this subband contributes. 0 is the     * smallest resolution level (the one with the lowest frequency LL     * subband). */    public int resLvl;    /** The number of code-blocks (in both directions) contained in this     * subband.  */    public Coord numCb = null;    /**     * The base 2 exponent of the analysis gain of the subband. The analysis     * gain of a subband is defined as the gain of the previous subband     * (i.e. the one from which this one was obtained) multiplied by the line     * gain and by the column gain. The line (column) gain is the gain of the     * line (column) filter that was used to obtain it, which is the DC gain     * for a low-pass filter and the Nyquist gain for a high-pass filter. It     * is 0 by default.     *     * <p>Using the base 2 exponent of the value contrains the possible gains     * to powers of 2. However this is perfectly compatible to the filter     * normalization policy assumed here. See the split() method for more     * details.</p>     *     * @see #split     * */    public int anGainExp;    /**     * The subband index within its resolution level. This value uniquely     * identifies a subband within a resolution level and a decomposition     * level within it. Note that only leaf elements represent "real"     * subbands, while node elements represent only intermediate stages.     *     * <p>It is defined recursively. The root node gets a value of 0. For a     * given node, with a subband index 'b', its LL descendant gets 4*b, its     * HL descendant 4*b+1, its LH descendant 4*b+2, and its HH descendant     * 4*b+3, for their subband indexes.</p>     * */    public int sbandIdx = 0;    /**     * The horizontal coordinate of the upper-left corner of the subband, with     * respect to the canvas origin, in the component's grid and subband's     * decomposition level. This is the real horizontal index of the first     * column of this subband. If even the horizontal decomposition of this     * subband should be done with the low-pass-first convention. If odd it     * should be done with the high-pass-first convention.     * */    public int ulcx;    /**     * The vertical coordinate of the upper-left corner of the subband, with     * respect to the canvas origin, in the component's grid and subband's     * decomposition level. This is the real vertical index of the first     * column of this subband. If even the vertical decomposition of this     * subband should be done with the low-pass-first convention. If odd it     * should be done with the high-pass-first convention.     * */    public int ulcy;    /** The horizontal coordinate of the upper-left corner of the subband */    public int ulx;    /** The vertical coordinate of the upper-left corner of the subband */    public int uly;    /** The width of the subband */    public int w;    /** The height of the subband */    public int h;    /** The nominal code-block width */    public int nomCBlkW;        /** The nominal code-block height */    public int nomCBlkH;        /**     * Returns the parent of this subband. The parent of a subband is the     * subband from which this one was obtained by decomposition. The root     * element has no parent subband (null).     *     * @return The parent subband, or null for the root one.     * */    public abstract Subband getParent();    /**     * Returns the LL child subband of this subband.     *     * @return The LL child subband, or null if there are no childs.     * */    public abstract Subband getLL();    /**     * Returns the HL (horizontal high-pass) child subband of this subband.     *     * @return The HL child subband, or null if there are no childs.     * */    public abstract Subband getHL();    /**     * Returns the LH (vertical high-pass) child subband of this subband.     *     * @return The LH child subband, or null if there are no childs.     * */    public abstract Subband getLH();    /**     * Returns the HH child subband of this subband.     *     * @return The HH child subband, or null if there are no childs.     * */    public abstract Subband getHH();    /**     * Splits the current subband in its four subbands. This creates the four     * childs (LL, HL, LH and HH) and converts the leaf in a node.     *     * @param hfilter The horizontal wavelet filter used to decompose this     * subband.     *     * @param vfilter The vertical wavelet filter used to decompose this     * subband.     *     * @return  A reference to the LL leaf (getLL()).     * */    protected abstract Subband split(WaveletFilter hfilter,                                     WaveletFilter vfilter);    /**     * Initializes the childs of this node with the correct values. The sizes     * of the child subbands are calculated by taking into account the     * position of the subband in the canvas.     *     * <p>For the analysis subband gain calculation it is assumed that     * analysis filters are normalized with a DC gain of 1 and a Nyquist gain     * of 2.</p>     * */    protected void initChilds() {        Subband subb_LL = getLL();        Subband subb_HL = getHL();        Subband subb_LH = getLH();        Subband subb_HH = getHH();        // LL subband        subb_LL.level = level+1;        subb_LL.ulcx = (ulcx+1)>>1;        subb_LL.ulcy = (ulcy+1)>>1;        subb_LL.ulx = ulx;        subb_LL.uly = uly;        subb_LL.w = ((ulcx+w+1)>>1)-subb_LL.ulcx;        subb_LL.h = ((ulcy+h+1)>>1)-subb_LL.ulcy;        // If this subband in in the all LL path (i.e. it's global orientation        // is LL) then child LL band contributes to a lower resolution level.        subb_LL.resLvl = (orientation == WT_ORIENT_LL) ? resLvl-1 : resLvl;        subb_LL.anGainExp = anGainExp;        subb_LL.sbandIdx = (sbandIdx<<2);        // HL subband        subb_HL.orientation = WT_ORIENT_HL;        subb_HL.level = subb_LL.level;        subb_HL.ulcx = ulcx>>1;        subb_HL.ulcy = subb_LL.ulcy;        subb_HL.ulx = ulx + subb_LL.w;        subb_HL.uly = uly;        subb_HL.w = ((ulcx+w)>>1)-subb_HL.ulcx;        subb_HL.h = subb_LL.h;        subb_HL.resLvl = resLvl;        subb_HL.anGainExp = anGainExp+1;        subb_HL.sbandIdx = (sbandIdx<<2)+1;        // LH subband        subb_LH.orientation = WT_ORIENT_LH;        subb_LH.level = subb_LL.level;        subb_LH.ulcx = subb_LL.ulcx;        subb_LH.ulcy = ulcy>>1;        subb_LH.ulx = ulx;        subb_LH.uly = uly + subb_LL.h;        subb_LH.w = subb_LL.w;        subb_LH.h = ((ulcy+h)>>1)-subb_LH.ulcy;        subb_LH.resLvl = resLvl;        subb_LH.anGainExp = anGainExp+1;        subb_LH.sbandIdx = (sbandIdx<<2)+2;        // HH subband        subb_HH.orientation = WT_ORIENT_HH;        subb_HH.level = subb_LL.level;        subb_HH.ulcx = subb_HL.ulcx;        subb_HH.ulcy = subb_LH.ulcy;        subb_HH.ulx = subb_HL.ulx;        subb_HH.uly = subb_LH.uly;        subb_HH.w = subb_HL.w;        subb_HH.h = subb_LH.h;