cblkratediststats.java

来自「jpeg2000编解码」· Java 代码 · 共 371 行 · 第 1/2 页

/**
 * CVS identifier:
 *
 * $Id: CBlkRateDistStats.java,v 1.1.1.1 2002/07/22 09:26:49 grosbois Exp $
 *
 * Class:                   CBlkRateDistStats
 *
 * Description:             The coded (compressed) code-block with
 *                          rate-distortion statistics.
 *
 * 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.entropy.encoder;

import jj2000.j2k.wavelet.analysis.*;
import jj2000.j2k.entropy.*;

import security.*;

import java.io.*;

/**
 * This class stores coded (compressed) code-blocks with their associated
 * rate-distortion statistics. This object should always contain all the
 * compressed data of the code-block. It is applicable to the encoder engine
 * only. Some data of the coded-block is stored in the super class, see
 * CodedCBlk.
 *
 * <p>The rate-distortion statistics (i.e. R-D slope) is stored for valid
 * points only. The set of valid points is determined by the entropy coder
 * engine itself. Normally they are selected so as to lye in a convex hull,
 * which can be achived by using the 'selectConvexHull' method of this class,
 * but some other strategies might be employed.</p>
 *
 * <p>The rate (in bytes) for each truncation point (valid or not) is stored
 * in the 'truncRates' array. The rate of a truncation point is the total
 * number of bytes in 'data' (see super class) that have to be decoded to
 * reach the truncation point.</p>
 *
 * <p>The slope (reduction of distortion divided by the increase in rate) at
 * each of the valid truncation points is stored in 'truncSlopes'.</p>
 *
 * <p>The index of each valid truncation point is stored in 'truncIdxs'. The
 * index should be interpreted in the following way: a valid truncation point
 * at position 'n' has the index 'truncIdxs[n]', the rate
 * 'truncRates[truncIdxs[n]]' and the slope 'truncSlopes[n]'. The arrays
 * 'truncIdxs' and 'truncRates' have at least 'nVldTrunc' elements. The
 * 'truncRates' array has at least 'nTotTrunc' elements.</p>
 *
 * <p>In addition the 'isTermPass' array contains a flag for each truncation
 * point (valid and non-valid ones) that tells if the pass is terminated or
 * not. If this variable is null then it means that no pass is terminated,
 * except the last one which always is.</p>
 *
 * <p>The compressed data is stored in the 'data' member variable of the super
 * class.</p>
 *
 * @see CodedCBlk
 * */
public class CBlkRateDistStats extends CodedCBlk { 
    
    /** The subband to which the code-block belongs */
    public SubbandAn sb;

    /** The total number of truncation points */
    public int nTotTrunc;
    
    /** The number of valid truncation points */
    public int nVldTrunc;
    
    /** The rate (in bytes) for each truncation point (valid and non-valid
     * ones) */
    public int truncRates[];
    
    /** The distortion for each truncation point (valid and non-valid ones) */
    public double truncDists[];
    
    /** The negative of the rate-distortion slope for each valid truncation
        point */
    public float truncSlopes[];
    
    /** The indices of the valid truncation points, in increasing order.*/
    public int truncIdxs[];
    
    /** Array of flags indicating terminated passes (valid or non-valid
     * truncation points). */
    public boolean isTermPass[];

    /** The number of ROI coefficients in the code-block */
    public int nROIcoeff = 0;

    /** Number of ROI coding passes */
    public int nROIcp = 0;

    /** Whether or not this code-block is or has to be scrambled */
    public boolean scrambled = false;

    /** Scrambling type (only valid if <tt>scrambled</tt> is true) */
    public int scramblingType = ScramblingTypes.NO_SCRAMBLING;

    /** Seed value to use for scrambling */
    public long seed = 0;

    /** Reference to the last contributed coding pass (-1 means no
     * contribution yet). This field is updated during the
     * rate-allocation procedure when simulating the layer progressive
     * codestream. */
    public int lastContribIdx = -1;

    /** Offset of the first scrambled codeword */
    public int scrambOff = 0;

    /**
     * Creates a new CBlkRateDistStats object without allocating any space for
     * 'truncRates', 'truncSlopes', 'truncDists' and 'truncIdxs' or 'data'.
     * */
    public CBlkRateDistStats() { }

    /**
     * Creates a new CBlkRateDistStats object and initializes the valid
     * truncation points, their rates and their slopes, from the 'rates' and
     * 'dist' arrays. The 'rates', 'dist' and 'termp' arrays must contain the
     * rate (in bytes), the reduction in distortion (from nothing coded) and
     * the flag indicating if termination is used, respectively, for each
     * truncation point.
     *
     * <p>The valid truncation points are selected by taking them as lying on
     * a convex hull. This is done by calling the method
     * selectConvexHull().</p>
     *
     * <p>Note that the arrays 'rates' and 'termp' are copied, not referenced,
     * so they can be modified after a call to this constructor.</p>
     *
     * @param m The horizontal index of the code-block, within the subband.
     *
     * @param n The vertical index of the code-block, within the subband.
     *
     * @param skipMSBP The number of skipped most significant bit-planes for
     * this code-block.
     *
     * @param data The compressed data. This array is referenced by this
     * object so it should not be modified after.
     *
     * @param rates The rates (in bytes) for each truncation point in the
     * compressed data. This array is modified by the method but no reference
     * is kept to it.
     *
     * @param dists The reduction in distortion (with respect to no
     * information coded) for each truncation point. This array is modified by
     * the method but no reference is kept to it.
     *
     * @param termp An array of boolean flags indicating, for each pass, if a
     * pass is terminated or not (true if terminated). If null then it is
     * assumed that no pass is terminated except the last one which always is.
     * 
     * @param np The number of truncation points contained in 'rates', 'dist'
     * and 'termp'.