/* * CVS identifier: * * $Id: AnWTFilterFloatLift9x7.java,v 1.1.1.1 2002/07/22 09:26:54 grosbois Exp $ * * Class:                   AnWTFilterFloatLift9x7 * * Description:             An analyzing wavelet filter implementing the *                          lifting 9x7 transform. * * * * 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.*;import jj2000.j2k.image.*;import jj2000.j2k.*;import jj2000.j2k.codestream.writer.*;/** * This class inherits from the analysis wavelet filter definition * for int data. It implements the forward wavelet transform * specifically for the 9x7 filter. The implementation is based on * the lifting scheme. * * <P>See the AnWTFilter class for details such as * normalization, how to split odd-length signals, etc. In particular, * this method assumes that the low-pass coefficient is computed first. * * @see AnWTFilter * @see AnWTFilterFloat * */public class AnWTFilterFloatLift9x7 extends AnWTFilterFloat {    /** The low-pass synthesis filter of the 9x7 wavelet transform */    private final static float LPSynthesisFilter[] =     { -0.091272f, -0.057544f, 0.591272f, 1.115087f,      0.591272f, -0.057544f, -0.091272f};    /** The high-pass synthesis filter of the 9x7 wavelet transform */    private final static float HPSynthesisFilter[] =        { 0.026749f, 0.016864f, -0.078223f, -0.266864f,          0.602949f,           -0.266864f, -0.078223f, 0.016864f, 0.026749f };        /** The value of the first lifting step coefficient */    public final static float ALPHA = -1.586134342f;    /** The value of the second lifting step coefficient */    public final static float BETA = -0.05298011854f;    /** The value of the third lifting step coefficient */    public final static float GAMMA = 0.8829110762f;    /** The value of the fourth lifting step coefficient */    public final static float DELTA = 0.4435068522f;    /** The value of the low-pass subband normalization factor */    public final static float KL = 0.8128930655f;    /** The value of the high-pass subband normalization factor */    public final static float KH = 1.230174106f;        /**     * An implementation of the analyze_lpf() method that works on int     * data, for the forward 9x7 wavelet transform using the     * lifting scheme. See the general description of the analyze_lpf()      * method in the AnWTFilter class for more details.     *     * <P>The coefficients of the first lifting step are [ALPHA 1 ALPHA].      *     * <P>The coefficients of the second lifting step are [BETA 1 BETA].     *      * <P>The coefficients of the third lifting step are [GAMMA 1 GAMMA].      *     * <P>The coefficients of the fourth lifting step are [DELTA 1 DELTA].     *     * <P>The low-pass and high-pass subbands are normalized by respectively     * a factor of KL and a factor of KH        *      * @param inSig This is the array that contains the input     * signal.     *     * @param inOff This is the index in inSig of the first sample to     * filter.     *     * @param inLen This is the number of samples in the input signal     * to filter.     *     * @param inStep This is the step, or interleave factor, of the     * input signal samples in the inSig array.     *     * @param lowSig This is the array where the low-pass output     * signal is placed.     *     * @param lowOff This is the index in lowSig of the element where     * to put the first low-pass output sample.     *     * @param lowStep This is the step, or interleave factor, of the     * low-pass output samples in the lowSig array.     *     * @param highSig This is the array where the high-pass output     * signal is placed.     *     * @param highOff This is the index in highSig of the element where     * to put the first high-pass output sample.     *     * @param highStep This is the step, or interleave factor, of the     * high-pass output samples in the highSig array.     * */    public         void analyze_lpf(float inSig[], int inOff, int inLen, int inStep,                      float lowSig[], int lowOff, int lowStep,                     float highSig[], int highOff, int highStep) {        int i,maxi;        int iStep = 2 * inStep; //Subsampling in inSig        int ik;    //Indexing inSig        int lk;    //Indexing lowSig        int hk;    //Indexing highSig                // Generate intermediate high frequency subband                //Initialize counters        ik = inOff + inStep;        lk = lowOff;        hk = highOff;                //Apply first lifting step to each "inner" sample        for( i = 1, maxi = inLen-1; i < maxi; i += 2 ) {                       highSig[hk] = inSig[ik] +                 ALPHA*(inSig[ik-inStep] + inSig[ik+inStep]);                        ik += iStep;               hk += highStep;        }        //Handle head boundary effect if input signal has even length        if(inLen % 2 == 0) {           highSig[hk] = inSig[ik] + 2*ALPHA*inSig[ik-inStep];        }                // Generate intermediate low frequency subband                //Initialize counters        ik = inOff;        lk = lowOff;        hk = highOff;         if(inLen>1) {            lowSig[lk] = inSig[ik] + 2*BETA*highSig[hk];        }        else {            lowSig[lk] = inSig[ik];        }                ik += iStep;        lk += lowStep;        hk += highStep;         //Apply lifting step to each "inner" sample        for( i = 2, maxi = inLen-1; i < maxi; i += 2 ) {            lowSig[lk] = inSig[ik] +                 BETA*(highSig[hk-highStep] + highSig[hk]);                        ik += iStep;            lk += lowStep;              hk += highStep;        }                //Handle head boundary effect if input signal has odd length        if((inLen % 2 == 1)&&(inLen>2)) {            lowSig[lk] =  inSig[ik] + 2*BETA*highSig[hk-highStep];        }                // Generate high frequency subband                 //Initialize counters        lk = lowOff;        hk = highOff;        //Apply first lifting step to each "inner" sample        for(i = 1, maxi = inLen-1; i < maxi; i += 2)  {                       highSig[hk] += GAMMA*(lowSig[lk] + lowSig[lk+lowStep]);                        lk += lowStep;               hk += highStep;        }        //Handle head boundary effect if input signal has even length        if(inLen % 2 == 0) {            highSig[hk] += 2*GAMMA*lowSig[lk];        }            // Generate low frequency subband                //Initialize counters        lk = lowOff;        hk = highOff;         //Handle tail boundary effect        //If access the overlap then perform the lifting step        if(inLen>1){            lowSig[lk] += 2*DELTA*highSig[hk];        }        lk += lowStep;        hk += highStep;         //Apply lifting step to each "inner" sample        for(i = 2, maxi = inLen-1; i < maxi; i += 2) {            lowSig[lk] +=                  DELTA*(highSig[hk - highStep] + highSig[hk]);                        lk += lowStep;              hk += highStep;        }                //Handle head boundary effect if input signal has odd length        if((inLen % 2 == 1)&&(inLen>2)) {            lowSig[lk] +=  2*DELTA*highSig[hk-highStep];        }        // Normalize low and high frequency subbands                 //Re-initialize counters        lk = lowOff;        hk = highOff;                 //Normalize each sample        for( i=0 ; i<(inLen>>1); i++ ) {            lowSig[lk] *= KL;            highSig[hk] *= KH;            lk += lowStep;              hk += highStep;        }               //If the input signal has odd length then normalize the last low-pass        //coefficient (if input signal is length one filter is identity)        if( inLen%2==1 && inLen != 1) {            lowSig[lk] *= KL;        }    }        /**     * An implementation of the analyze_hpf() method that works on int     * data, for the forward 9x7 wavelet transform using the     * lifting scheme. See the general description of the analyze_hpf() method      * in the AnWTFilter class for more details.     *     * <P>The coefficients of the first lifting step are [ALPHA 1 ALPHA].      *     * <P>The coefficients of the second lifting step are [BETA 1 BETA].     *      * <P>The coefficients of the third lifting step are [GAMMA 1 GAMMA].      *     * <P>The coefficients of the fourth lifting step are [DELTA 1 DELTA].     *     * <P>The low-pass and high-pass subbands are normalized by respectively     * a factor of KL and a factor of KH        *      * @param inSig This is the array that contains the input     * signal.     *     * @param inOff This is the index in inSig of the first sample to     * filter.     *     * @param inLen This is the number of samples in the input signal     * to filter.     *     * @param inStep This is the step, or interleave factor, of the     * input signal samples in the inSig array.     *     * @param lowSig This is the array where the low-pass output     * signal is placed.     *     * @param lowOff This is the index in lowSig of the element where     * to put the first low-pass output sample.     *     * @param lowStep This is the step, or interleave factor, of the     * low-pass output samples in the lowSig array.     *     * @param highSig This is the array where the high-pass output     * signal is placed.     *     * @param highOff This is the index in highSig of the element where     * to put the first high-pass output sample.     *     * @param highStep This is the step, or interleave factor, of the     * high-pass output samples in the highSig array.     *     * @see AnWTFilter#analyze_hpf     * */    public void analyze_hpf(float inSig[], int inOff, int inLen, int inStep,                     float lowSig[], int lowOff, int lowStep,                    float highSig[], int highOff, int highStep) {                            int i,maxi;        int iStep = 2 * inStep; //Subsampling in inSig        int ik;    //Indexing inSig        int lk;    //Indexing lowSig        int hk;    //Indexing highSig                // Generate intermediate high frequency subband                 //Initialize counters        ik = inOff;        lk = lowOff;        hk = highOff;                if ( inLen>1 ) {            // apply symmetric extension.            highSig[hk] = inSig[ik] + 2*ALPHA*inSig[ik+inStep];        }        else {	    // Normalize for Nyquist gain