/* * CVS identifier: * * $Id: StdDequantizerParams.java,v 1.9 2000/09/19 14:12:09 grosbois Exp $ * * Class: StdDequantizerParams * * Description: Parameters for the scalar deadzone dequantizers * * * * COPYRIGHT: * * This software module was originally developed by Raphaël Grosbois and * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel * Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David * Bouchard, Félix 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. */ using System; using CSJ2K.j2k.io; using CSJ2K.j2k.wavelet; using CSJ2K.j2k.quantization; using CSJ2K.j2k.entropy.decoder; using CSJ2K.j2k.image; using CSJ2K.j2k.util; using CSJ2K.j2k.codestream; using CSJ2K.j2k.codestream.reader; namespace CSJ2K.j2k.quantization.dequantizer { /// This class holds the parameters for the scalar deadzone dequantizer /// (StdDequantizer class) for the current tile. Its constructor decodes the /// parameters from the main header and tile headers. /// /// /// /// /// public class StdDequantizerParams:DequantizerParams { /// Returns the type of the dequantizer for which the parameters are. The /// types are defined in the Dequantizer class. /// /// /// The type of the dequantizer for which the parameters /// are. Always Q_TYPE_SCALAR_DZ. /// /// /// /// /// override public int DequantizerType { get { return CSJ2K.j2k.quantization.QuantizationType_Fields.Q_TYPE_SCALAR_DZ; } } /// The quantization step "exponent" value, for each resolution level and /// subband, as it appears in the codestream. The first index is the /// resolution level, and the second the subband index (within the /// resolution level), as specified in the Subband class. When in derived /// quantization mode only the first resolution level (level 0) appears. /// ///

For non-reversible systems this value corresponds to ceil(log2(D')), /// where D' is the quantization step size normalized to data of a dynamic /// range of 1. The true quantization step size is (2^R)*D', where R is /// ceil(log2(dr)), where 'dr' is the dynamic range of the subband samples, /// in the corresponding subband. /// ///

For reversible systems the exponent value in 'exp' is used to /// determine the number of magnitude bits in the quantized /// coefficients. It is, in fact, the dynamic range of the subband data. /// ///

In general the index of the first subband in a resolution level is /// not 0. The exponents appear, within each resolution level, at their /// subband index, and not in the subband order starting from 0. For /// instance, resolution level 3, the first subband has the index 16, then /// the exponent of the subband is exp[3][16], not exp[3][0]. /// ///

/// /// /// public int[][] exp; /// The quantization step for non-reversible systems, normalized to a /// dynamic range of 1, for each resolution level and subband, as derived /// from the exponent-mantissa representation in the codestream. The first /// index is the resolution level, and the second the subband index (within /// the resolution level), as specified in the Subband class. When in /// derived quantization mode only the first resolution level (level 0) /// appears. /// ///

The true step size D is obtained as follows: D=(2^R)*D', where /// 'R=ceil(log2(dr))' and 'dr' is the dynamic range of the subband /// samples, in the corresponding subband. /// ///

This value is 'null' for reversible systems (i.e. there is no true /// quantization, 'D' is always 1). /// ///

In general the index of the first subband in a resolution level is /// not 0. The steps appear, within each resolution level, at their subband /// index, and not in the subband order starting from 0. For instance, if /// resolution level 3, the first subband has the index 16, then the step /// of the subband is nStep[3][16], not nStep[3][0]. /// ///

/// /// /// public float[][] nStep; } }