ebcotlayer.java

jpeg2000算法实现

/* 
 * CVS identifier:
 * 
 * $Id: EBCOTLayer.java,v 1.8 2000/09/05 09:23:35 grosbois Exp $
 * 
 * Class:                   EBCOTLayer
 * 
 * Description:             Storage for layer information,
 *                          used by EBCOTRateAllocator
 * 
 *                          class that was in EBCOTRateAllocator.
 * 
 * 
 * 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;

/**
 * This class holds information about each layer that is to be, or has already
 * been, allocated . It is used in the rate-allocation process to keep the
 * necessary layer information. It is used by EBCOTRateAllocator.
 *
 * @see EBCOTRateAllocator
 **/
class EBCOTLayer {
    /**
     * This is the maximum number of bytes that should be allocated for
     * this and previous layers. This is actually the target length for
     * the layer.
     **/
    int maxBytes;
    
    /**
     * The actual number of bytes which are consumed by the the current and
     * any previous layers. This is the result from a simulation when the
     * threshold for the layer has been set.
     **/
    int actualBytes;
    
    /**
     * If true the `maxBytes' value is the hard maximum and the threshold is
     * determined iteratively. If false the `maxBytes' value is a target 
     * bitrate and the threshold is estimated from summary information
     * accumulated during block coding.
     **/
    boolean optimize;
    
    /** 
     * The rate-distortion threshold associated with the bit-stream
     * layer. When set the layer includes data up to the truncation points 
     * that have a slope no smaller than 'rdThreshold'.
     **/        
    float rdThreshold;
}