001/*
002 * $RCSfile: CBlkWTDataSrc.java,v $
003 * $Revision: 1.1 $
004 * $Date: 2005/02/11 05:02:30 $
005 * $State: Exp $
006 *
007 * Class:                   CBlkWTDataSrc
008 *
009 * Description:             Interface that define methods for transfer of WT
010 *                          data in a code-block basis.
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 *
046 *
047 */
048
049
050package jj2000.j2k.wavelet.analysis;
051
052import jj2000.j2k.wavelet.WaveletTransform;
053
054/**
055 * This abstract class defines methods to transfer wavelet data in a
056 * code-block by code-block basis. In each call to 'getNextCodeBlock()' or
057 * 'getNextInternCodeBlock()' a new code-block is returned. The code-blocks
058 * are returned in no specific order.
059 *
060 * <P>This class is the source of data for the quantizer. See the 'Quantizer'
061 * class.
062 *
063 * <P>Note that no more of one object may request data, otherwise one object
064 * would get some of the data and another one another part, in no defined
065 * manner.
066 *
067 * @see ForwWTDataProps
068 *
069 * @see WaveletTransform
070 *
071 * @see jj2000.j2k.quantization.quantizer.CBlkQuantDataSrcEnc
072 *
073 * @see jj2000.j2k.quantization.quantizer.Quantizer
074 * */
075public interface CBlkWTDataSrc extends ForwWTDataProps {
076
077    /**
078     * Returns the position of the fixed point in the specified component, or
079     * equivalently the number of fractional bits. This is the position of the
080     * least significant integral (i.e. non-fractional) bit, which is
081     * equivalent to the number of fractional bits. For instance, for
082     * fixed-point values with 2 fractional bits, 2 is returned. For
083     * floating-point data this value does not apply and 0 should be
084     * returned. Position 0 is the position of the least significant bit in
085     * the data.
086     *
087     * @param n The index of the component.
088     *
089     * @return The position of the fixed-point, which is the same as
090     * the number of fractional bits. For floating-point data 0 is
091     * returned.
092     *
093     *
094     * */
095     public int getFixedPoint(int n);
096
097    /** Return the data type of this CBlkWTDataSrc for the given
098     *  component in the current tile. Its value should be either
099     *  DataBlk.TYPE_INT or DataBlk.TYPE_FLOAT but can change
100     *  according to the current tile-component.
101     *
102     * @param t Tile index
103     *
104     * @param c Component index
105     *
106     * @return Current data type
107     *
108     */
109    public int getDataType(int t,int c);
110
111    /**
112     * Returns the next code-block in the current tile for the specified
113     * component, as a copy (see below). The order in which code-blocks are
114     * returned is not specified. However each code-block is returned only
115     * once and all code-blocks will be returned if the method is called 'N'
116     * times, where 'N' is the number of code-blocks in the tile. After all
117     * the code-blocks have been returned for the current tile calls to this
118     * method will return 'null'.
119     *
120     * <P>When changing the current tile (through 'setTile()' or 'nextTile()')
121     * this method will always return the first code-block, as if this method
122     * was never called before for the new current tile.
123     *
124     * <P>The data returned by this method is always a copy of the internal
125     * data of this object, if any, and it can be modified "in place" without
126     * any problems after being returned. The 'offset' of the returned data is
127     * 0, and the 'scanw' is the same as the code-block width.  The 'magbits'
128     * of the returned data is not set by this method and should be
129     * ignored. See the 'CBlkWTData' class.
130     *
131     * <P>The 'ulx' and 'uly' members of the returned 'CBlkWTData' object
132     * contain the coordinates of the top-left corner of the block, with
133     * respect to the tile, not the subband.
134     *
135     * @param n The component for which to return the next code-block.
136     *
137     * @param cblk If non-null this object will be used to return the new
138     * code-block. If null a new one will be allocated and returned. If the
139     * "data" array of the object is non-null it will be reused, if possible,
140     * to return the data.
141     *
142     * @return The next code-block in the current tile for component 'n', or
143     * null if all code-blocks for the current tile have been returned.
144     *
145     * @see CBlkWTData
146     *
147     *
148     * */
149    public abstract CBlkWTData getNextCodeBlock(int n, CBlkWTData cblk);
150
151    /**
152     * Returns the next code-block in the current tile for the specified
153     * component. The order in which code-blocks are returned is not
154     * specified. However each code-block is returned only once and all
155     * code-blocks will be returned if the method is called 'N' times, where
156     * 'N' is the number of code-blocks in the tile. After all the code-blocks
157     * have been returned for the current tile calls to this method will
158     * return 'null'.
159     *
160     * <P>When changing the current tile (through 'setTile()' or 'nextTile()')
161     * this method will always return the first code-block, as if this method
162     * was never called before for the new current tile.
163     *
164     * <P>The data returned by this method can be the data in the internal
165     * buffer of this object, if any, and thus can not be modified by the
166     * caller. The 'offset' and 'scanw' of the returned data can be
167     * arbitrary. The 'magbits' of the returned data is not set by this method
168     * and should be ignored. See the 'CBlkWTData' class.
169     *
170     * <P>The 'ulx' and 'uly' members of the returned 'CBlkWTData' object
171     * contain the coordinates of the top-left corner of the block, with
172     * respect to the tile, not the subband.
173     *
174     * @param n The component for which to return the next code-block.
175     *
176     * @param cblk If non-null this object will be used to return the new
177     * code-block. If null a new one will be allocated and returned. If the
178     * "data" array of the object is non-null it will be reused, if possible,
179     * to return the data.
180     *
181     * @return The next code-block in the current tile for component 'n', or
182     * null if all code-blocks for the current tile have been returned.
183     *
184     * @see CBlkWTData
185     *
186     *
187     * */
188    public abstract CBlkWTData getNextInternCodeBlock(int n, CBlkWTData cblk);
189
190}