001: /*
002: * $RCSfile: CBlkWTDataSrcDec.java,v $
003: * $Revision: 1.1 $
004: * $Date: 2005/02/11 05:02:31 $
005: * $State: Exp $
006: *
007: * Class: CBlkWTDataSrcDec
008: *
009: * Description: Interface that define methods for trasnfer of WT
010: * data in a code-block basis (decoder side).
011: *
012: *
013: *
014: * COPYRIGHT:
015: *
016: * This software module was originally developed by Raphaël Grosbois and
017: * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
018: * Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
019: * Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
020: * Centre France S.A) in the course of development of the JPEG2000
021: * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
022: * software module is an implementation of a part of the JPEG 2000
023: * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
024: * Systems AB and Canon Research Centre France S.A (collectively JJ2000
025: * Partners) agree not to assert against ISO/IEC and users of the JPEG
026: * 2000 Standard (Users) any of their rights under the copyright, not
027: * including other intellectual property rights, for this software module
028: * with respect to the usage by ISO/IEC and Users of this software module
029: * or modifications thereof for use in hardware or software products
030: * claiming conformance to the JPEG 2000 Standard. Those intending to use
031: * this software module in hardware or software products are advised that
032: * their use may infringe existing patents. The original developers of
033: * this software module, JJ2000 Partners and ISO/IEC assume no liability
034: * for use of this software module or modifications thereof. No license
035: * or right to this software module is granted for non JPEG 2000 Standard
036: * conforming products. JJ2000 Partners have full right to use this
037: * software module for his/her own purpose, assign or donate this
038: * software module to any third party and to inhibit third parties from
039: * using this software module for non JPEG 2000 Standard conforming
040: * products. This copyright notice must be included in all copies or
041: * derivative works of this software module.
042: *
043: * Copyright (c) 1999/2000 JJ2000 Partners.
044: * */
045: package jj2000.j2k.wavelet.synthesis;
046:
047: import jj2000.j2k.image.*;
048: import jj2000.j2k.wavelet.*;
049:
050: /**
051: * This abstract class defines methods to transfer wavelet data in a
052: * code-block by code-block basis, for the decoder side. In each call to
053: * 'getCodeBlock()' or 'getInternCodeBlock()' a new code-block is
054: * returned. The code-blocks are returned in no specific order.
055: *
056: * <P>This class is the source of data, in general, for the inverse wavelet
057: * transforms. See the 'InverseWT' class.
058: *
059: * @see InvWTData
060: *
061: * @see WaveletTransform
062: *
063: * @see jj2000.j2k.quantization.dequantizer.CBlkQuantDataSrcDec
064: *
065: * @see InverseWT
066: * */
067: public interface CBlkWTDataSrcDec extends InvWTData {
068:
069: /**
070: * Returns the number of bits, referred to as the "range bits",
071: * corresponding to the nominal range of the data in the specified
072: * component.
073: *
074: * <P>The returned value corresponds to the nominal dynamic range of the
075: * reconstructed image data, not of the wavelet coefficients
076: * themselves. This is because different subbands have different gains and
077: * thus different nominal ranges. To have an idea of the nominal range in
078: * each subband the subband analysis gain value from the subband tree
079: * structure, returned by the 'getSubbandTree()' method, can be used. See
080: * the 'Subband' class for more details.
081: *
082: * <P>If this number is <i>b</b> then for unsigned data the nominal range
083: * is between 0 and 2^b-1, and for signed data it is between -2^(b-1) and
084: * 2^(b-1)-1.
085: *
086: * @param c The index of the component
087: *
088: * @return The number of bits corresponding to the nominal range of the
089: * data.
090: *
091: * @see Subband
092: * */
093: public int getNomRangeBits(int c);
094:
095: /**
096: * Returns the position of the fixed point in the specified component, or
097: * equivalently the number of fractional bits. This is the position of the
098: * least significant integral (i.e. non-fractional) bit, which is
099: * equivalent to the number of fractional bits. For instance, for
100: * fixed-point values with 2 fractional bits, 2 is returned. For
101: * floating-point data this value does not apply and 0 should be
102: * returned. Position 0 is the position of the least significant bit in
103: * the data.
104: *
105: * @param c The index of the component.
106: *
107: * @return The position of the fixed-point, which is the same as the
108: * number of fractional bits. For floating-point data 0 is returned.
109: * */
110: public int getFixedPoint(int c);
111:
112: /**
113: * Returns the specified code-block in the current tile for the specified
114: * component, as a copy (see below).
115: *
116: * <P>The returned code-block may be progressive, which is indicated by
117: * the 'progressive' variable of the returned 'DataBlk' object. If a
118: * code-block is progressive it means that in a later request to this
119: * method for the same code-block it is possible to retrieve data which is
120: * a better approximation, since meanwhile more data to decode for the
121: * code-block could have been received. If the code-block is not
122: * progressive then later calls to this method for the same code-block
123: * will return the exact same data values.
124: *
125: * <P>The data returned by this method is always a copy of the internal
126: * data of this object, if any, and it can be modified "in place" without
127: * any problems after being returned. The 'offset' of the returned data is
128: * 0, and the 'scanw' is the same as the code-block width. See the
129: * 'DataBlk' class.
130: *
131: * @param c The component for which to return the next code-block.
132: *
133: * @param m The vertical index of the code-block to return,
134: * in the specified subband.
135: *
136: * @param n The horizontal index of the code-block to return,
137: * in the specified subband.
138: *
139: * @param sb The subband in which the code-block to return is.
140: *
141: * @param cblk If non-null this object will be used to return the new
142: * code-block. If null a new one will be allocated and returned. If the
143: * "data" array of the object is non-null it will be reused, if possible,
144: * to return the data.
145: *
146: * @return The next code-block in the current tile for component 'n', or
147: * null if all code-blocks for the current tile have been returned.
148: *
149: * @see DataBlk
150: * */
151: public DataBlk getCodeBlock(int c, int m, int n, SubbandSyn sb,
152: DataBlk cblk);
153:
154: /**
155: * Returns the specified code-block in the current tile for the specified
156: * component (as a reference or copy).
157: *
158: * <P>The returned code-block may be progressive, which is indicated by
159: * the 'progressive' variable of the returned 'DataBlk'
160: * object. If a code-block is progressive it means that in a later request
161: * to this method for the same code-block it is possible to retrieve data
162: * which is a better approximation, since meanwhile more data to decode
163: * for the code-block could have been received. If the code-block is not
164: * progressive then later calls to this method for the same code-block
165: * will return the exact same data values.
166: *
167: * <P>The data returned by this method can be the data in the internal
168: * buffer of this object, if any, and thus can not be modified by the
169: * caller. The 'offset' and 'scanw' of the returned data can be
170: * arbitrary. See the 'DataBlk' class.
171: *
172: * @param c The component for which to return the next code-block.
173: *
174: * @param m The vertical index of the code-block to return, in the
175: * specified subband.
176: *
177: * @param n The horizontal index of the code-block to return, in the
178: * specified subband.
179: *
180: * @param sb The subband in which the code-block to return is.
181: *
182: * @param cblk If non-null this object will be used to return the new
183: * code-block. If null a new one will be allocated and returned. If the
184: * "data" array of the object is non-null it will be reused, if possible,
185: * to return the data.
186: *
187: * @return The next code-block in the current tile for component 'n', or
188: * null if all code-blocks for the current tile have been returned.
189: *
190: * @see DataBlk
191: * */
192: public DataBlk getInternCodeBlock(int c, int m, int n,
193: SubbandSyn sb, DataBlk cblk);
194: }
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