subbandan.java

jpeg2000编解码

/*
 * CVS identifier:
 *
 * $Id: SubbandAn.java,v 1.1.1.1 2002/07/22 09:26:55 grosbois Exp $
 *
 * Class:                   SubbandAn
 *
 * Description:             Element for a tree structure for a descripotion
 *                          of subbands on the anslysis side.
 *
 *
 *
 * 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.analysis;

import jj2000.j2k.wavelet.*;

/**
 * This class represents a subband in a bidirectional tree structure that
 * describes the subband decomposition for a wavelet transform, specifically
 * for the analysis side.
 *
 * <p>The element can be either a node or a leaf of the tree. If it is a node
 * then ther are 4 descendants (LL, HL, LH and HH). If it is a leaf there are
 * no descendants.</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 has no parent
 * (i.e.it's null), for obvious reasons.</p>
 * */
public class SubbandAn extends Subband {

    /** The reference to the parent of this subband. It is null for the root
     * element. It is null by default.  */
    public SubbandAn parent = null;

    /** The reference to the LL subband resulting from the decomposition of
     * this subband. It is null by default.  */
    public SubbandAn subb_LL;

    /** The reference to the HL subband (horizontal high-pass) resulting from
     * the decomposition of this subband. It is null by default.  */
    public SubbandAn subb_HL;

    /** The reference to the LH subband (vertical high-pass) resulting from
     * the decomposition of this subband. It is null by default.
     * */
    public SubbandAn subb_LH;

    /** The reference to the HH subband resulting from the decomposition of
     * this subband. It is null by default.  */
    public SubbandAn subb_HH;

    /** The horizontal analysis filter used to decompose this subband. This is
     * applicable to "node" elements only. The default value is null. */
    public AnWTFilter hFilter;
       
    /** The vertical analysis filter used to decompose this subband. This is
     * applicable to "node" elements only. The default value is null. */
    public AnWTFilter vFilter;

    /** The L2-norm of the synthesis basis waveform of this subband,
     * applicable to "leafs" only. By default it is -1 (i.e. not calculated
     * yet).
     * */
    public float l2Norm = -1.0f;

    /**
     * The contribution to the MSE or WMSE error that would result in the
     * image if there was an error of exactly one quantization step size in
     * the sample of the subband. This value is expressed relative to a
     * nominal dynamic range in the image domain of exactly 1.0. This field
     * contains valid data only after quantization 9See Quantizer).
     *
     * @see jj2000.j2k.quantization.quantizer.Quantizer
     * */
    public float stepWMSE;
       
    /**
     * Creates a SubbandAn element with all the default values. The dimensions
     * are (0,0) and the upper left corner is (0,0).
     * */
    public SubbandAn() { }

    /**
     * Creates the top-level node and the entire subband tree, with the
     * top-level dimensions, the number of decompositions, and the
     * decomposition tree as specified.
     *
     * <p>This constructor just calls the same constructor of the super class,
     * and then calculates the L2-norm (or energy weight) of each leaf.</p>
     *
     * <p>This constructor does not initialize the value of the magBits or
     * stepWMSE member variables. This variables are normally initialized by
     * the quantizer (see Quantizer).</p>
     *
     * @param w The top-level width
     *
     * @param h The top-level height
     *
     * @param ulcx The horizontal coordinate of the upper-left corner with
     * respect to the canvas origin, in the component grid.
     *
     * @param ulcy The vertical coordinate of the upper-left corner with
     * respect to the canvas origin, in the component grid.
     *
     * @param lvls The number of levels (or LL decompositions) in the tree.
     *
     * @param hfilters The horizontal wavelet analysis filters for each
     * resolution level, starting at resolution level 0.
     *
     * @param vfilters The vertical wavelet analysis filters for each
     * resolution level, starting at resolution level 0.
     *
     * @see Subband#Subband(int,int,int,int,int,
     * WaveletFilter[],WaveletFilter[])
     *
     * @see jj2000.j2k.quantization.quantizer.Quantizer
     * */
    public SubbandAn(int w, int h, int ulcx, int ulcy, int lvls,
                     WaveletFilter hfilters[], WaveletFilter vfilters[]) {
        super(w,h,ulcx,ulcy,lvls,hfilters,vfilters);
        // Caculate the L2-norms
        calcL2Norms();
    }

    /**
     * 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 Subband getParent() {
        return parent;
    }

    /**
     * Returns the LL child subband of this subband.
     *
     * @return The LL child subband, or null if there are no childs.
     * */
    public Subband getLL() {
        return subb_LL;
    }

    /**
     * Returns the HL (horizontal high-pass) child subband of this subband.
     *
     * @return The HL child subband, or null if there are no childs.
     * */
    public Subband getHL() {
        return subb_HL;
    }

    /**
     * Returns the LH (vertical high-pass) child subband of this subband.
     *
     * @return The LH child subband, or null if there are no childs.
     * */
    public Subband getLH() {
        return subb_LH;
    }

    /**
     * Returns the HH child subband of this subband.
     *
     * @return The HH child subband, or null if there are no childs.
     * */
    public Subband getHH() {
        return subb_HH;
    }

    /**
     * Splits the current subband in its four subbands. It changes the status
     * of this element (from a leaf to a node, and sets the filters), creates
     * the childs and initializes them. An IllegalArgumentException is thrown
     * if this subband is not a leaf.
     *
     * <p>It uses the initChilds() method to initialize the childs.</p>