/* * CVS identifier: * * $Id: SynWTFilterFloatLift9x7.java,v 1.12 2000/12/12 16:54:24 grosbois Exp $ * * Class:                   SynWTFilterFloatLift9x7 * * Description:             A synthetizing 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.synthesis;import jj2000.j2k.wavelet.*;import jj2000.j2k.image.*;import jj2000.j2k.*;/** * This class inherits from the synthesis wavelet filter definition for int * data. It implements the inverse wavelet transform specifically for the 9x7 * filter. The implementation is based on the lifting scheme. * * <P>See the SynWTFilter 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 SynWTFilter * @see SynWTFilterFloat * */public class SynWTFilterFloatLift9x7 extends SynWTFilterFloat {        /** 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 = 0.443568522f;    /** The value of the low-pass subband normalization factor */    public final static float KL = 0.8128930655f;//1.149604398f;    /** The value of the high-pass subband normalization factor */    public final static float KH = 1.230174106f;//0.8698644523f;        /**     * An implementation of the synthetize_lpf() method that works on int     * data, for the inverse 9x7 wavelet transform using the lifting     * scheme. See the general description of the synthetize_lpf() method in     * the SynWTFilter class for more details.     *     * <P>The low-pass and high-pass subbands are normalized by respectively a     * factor of 1/KL and a factor of 1/KH     *     * <P>The coefficients of the first lifting step are [-DELTA 1 -DELTA].      *     * <P>The coefficients of the second lifting step are [-GAMMA 1 -GAMMA].     *      * <P>The coefficients of the third lifting step are [-BETA 1 -BETA].      *     * <P>The coefficients of the fourth lifting step are [-ALPHA 1 -ALPHA].     *     * @param lowSig This is the array that contains the low-pass input     * signal.     *     * @param lowOff This is the index in lowSig of the first sample to     * filter.     *     * @param lowLen This is the number of samples in the low-pass input     * signal to filter.     *     * @param lowStep This is the step, or interleave factor, of the low-pass     * input signal samples in the lowSig array.     *     * @param highSig This is the array that contains the high-pass input     * signal.     *     * @param highOff This is the index in highSig of the first sample to     * filter.     *     * @param highLen This is the number of samples in the high-pass input     * signal to filter.     *     * @param highStep This is the step, or interleave factor, of the     * high-pass input signal samples in the highSig array.     *     * @param outSig This is the array where the output signal is placed. It     * should be long enough to contain the output signal.     *     * @param outOff This is the index in outSig of the element where to put     * the first output sample.     *     * @param outStep This is the step, or interleave factor, of the output     * samples in the outSig array.     *     * @see SynWTFilter#synthetize_lpf     * */    public        void synthetize_lpf(float[] lowSig, int lowOff, int lowLen, int lowStep,                        float[] highSig, int highOff, int highLen, int highStep,                        float[] outSig, int outOff, int outStep) {                                int i;        int outLen = lowLen + highLen; //Length of the output signal        int iStep = 2*outStep; //Upsampling in outSig        int ik; //Indexing outSig        int lk; //Indexing lowSig        int hk; //Indexing highSig                // Generate intermediate low frequency subband	float sample = 0;        //Initialize counters        lk = lowOff;        hk = highOff;        ik = outOff;                //Handle tail boundary effect. Use symmetric extension        if(outLen>1) {            outSig[ik] = lowSig[lk]/KL - 2*DELTA*highSig[hk]/KH;        }	else {	    outSig[ik] = lowSig[lk];	}                lk += lowStep;        hk += highStep;    	ik += iStep;    	        //Apply lifting step to each "inner" sample        for(i = 2; i<outLen-1; i+=2, ik+=iStep, lk+=lowStep, hk+=highStep) {            outSig[ik] = lowSig[lk]/KL -             	DELTA*(highSig[hk-highStep] + highSig[hk])/KH;        }                //Handle head boundary effect if input signal has odd length        if(outLen%2 == 1) {            if(outLen>2){                outSig[ik] = lowSig[lk]/KL -                 2*DELTA*highSig[hk-highStep]/KH;            }        }                // Generate intermediate high frequency subband                 //Initialize counters        lk = lowOff;        hk = highOff;    	ik = outOff + outStep;        //Apply lifting step to each "inner" sample        for(i = 1; i<outLen-1; i+=2, ik+=iStep, hk+=highStep, lk+=lowStep) {            outSig[ik] = highSig[hk]/KH -                 GAMMA*(outSig[ik-outStep] + outSig[ik+outStep]);    	}        //Handle head boundary effect if output signal has even length        if(outLen % 2 == 0) {            outSig[ik] = highSig[hk]/KH - 2*GAMMA*outSig[ik-outStep];        }               // Generate even samples (inverse low-pass filter)                //Initialize counters        ik = outOff;         //Handle tail boundary effect        //If access the overlap then perform the lifting step.    	if(outLen>1) {            outSig[ik] -= 2*BETA*outSig[ik+outStep];        }        ik += iStep;         //Apply lifting step to each "inner" sample        for(i=2; i<outLen-1; i+=2, ik+=iStep) {            outSig[ik] -= BETA*(outSig[ik-outStep] + outSig[ik+outStep]);        }                //Handle head boundary effect if input signal has odd length        if(outLen%2 == 1 && outLen>2) {            outSig[ik] -= 2*BETA*outSig[ik-outStep];        }        // Generate odd samples (inverse high pass-filter)                 //Initialize counters        ik = outOff + outStep;        //Apply first lifting step to each "inner" sample        for(i=1; i<outLen-1; i+=2, ik+=iStep) {                       outSig[ik] -= ALPHA*(outSig[ik-outStep] + outSig[ik+outStep]);        }        //Handle head boundary effect if input signal has even length        if(outLen%2 == 0) {            outSig[ik] -= 2*ALPHA*outSig[ik-outStep];        }    }        /**     * An implementation of the synthetize_hpf() method that works on int     * data, for the inverse 9x7 wavelet transform using the lifting     * scheme. See the general description of the synthetize_hpf() method in     * the SynWTFilter class for more details.     *     * <P>The low-pass and high-pass subbands are normalized by respectively     * a factor of 1/KL and a factor of 1/KH        *     * <P>The coefficients of the first lifting step are [-DELTA 1 -DELTA].      *     * <P>The coefficients of the second lifting step are [-GAMMA 1 -GAMMA].     *      * <P>The coefficients of the third lifting step are [-BETA 1 -BETA].      *     * <P>The coefficients of the fourth lifting step are [-ALPHA 1 -ALPHA].     *     * @param lowSig This is the array that contains the low-pass     * input signal.     *     * @param lowOff This is the index in lowSig of the first sample to     * filter.     *     * @param lowLen This is the number of samples in the low-pass input     * signal to filter.     *     * @param lowStep This is the step, or interleave factor, of the low-pass     * input signal samples in the lowSig array.     *     * @param highSig This is the array that contains the high-pass input     * signal.     *     * @param highOff This is the index in highSig of the first sample to     * filter.     *     * @param highLen This is the number of samples in the high-pass input     * signal to filter.     *     * @param highStep This is the step, or interleave factor, of the     * high-pass input signal samples in the highSig array.     *     * @param outSig This is the array where the output signal is placed. It     * should be long enough to contain the output signal.     *     * @param outOff This is the index in outSig of the element where to put     * the first output sample.     *     * @param outStep This is the step, or interleave factor, of the output     * samples in the outSig array.     *     * @see SynWTFilter#synthetize_hpf     * */    public        void synthetize_hpf(float[] lowSig, int lowOff, int lowLen, int lowStep,                        float[] highSig, int highOff, int highLen, int highStep,                        float[] outSig, int outOff, int outStep) {                                int i;        int outLen = lowLen + highLen; //Length of the output signal