001/*
002 * $RCSfile: SubbandSyn.java,v $
003 * $Revision: 1.1 $
004 * $Date: 2005/02/11 05:02:33 $
005 * $State: Exp $
006 *
007 * Class:                   SubbandSyn
008 *
009 * Description:             Element for a tree structure for a description
010 *                          of subband for the synthesis 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 *
046 *
047 */
048
049
050package jj2000.j2k.wavelet.synthesis;
051
052import jj2000.j2k.wavelet.Subband;
053import jj2000.j2k.wavelet.WaveletFilter;
054
055/**
056 * This class represents a subband in a tree structure that describes
057 * the subband decomposition for a wavelet transform, specifically for
058 * the syhthesis side.
059 *
060 * <P>The element can be either a node or a leaf of the tree. If it is
061 * a node then ther are 4 descendants (LL, HL, LH and HH). If it is a
062 * leaf there are no descendants.
063 *
064 * <P>The tree is bidirectional. Each element in the tree structure
065 * has a "parent", which is the subband from which the element was
066 * obtained by decomposition. The only exception is the root element
067 * which has no parent (i.e.it's null), for obvious reasons.
068 * */
069public class SubbandSyn extends Subband {
070
071    /**
072     * The reference to the parent of this subband. It is null for the
073     * root element. It is null by default.  */
074    public SubbandSyn parent;
075
076    /**
077     * The reference to the LL subband resulting from the
078     * decomposition of this subband. It is null by default.  */
079    public SubbandSyn subb_LL;
080
081    /**
082     * The reference to the HL subband (horizontal high-pass)
083     * resulting from the decomposition of this subband. It is null by
084     * default.  */
085    public SubbandSyn subb_HL;
086
087    /**
088     * The reference to the LH subband (vertical high-pass) resulting
089     * from the decomposition of this subband. It is null by default.
090     * */
091    public SubbandSyn subb_LH;
092
093    /**
094     * The reference to the HH subband resulting from the
095     * decomposition of this subband. It is null by default.
096     */
097    public SubbandSyn subb_HH;
098
099    /** The horizontal analysis filter used to recompose this subband,
100        from its childs. This is applicable to "node" elements
101        only. The default value is null. */
102    public SynWTFilter hFilter;
103
104    /** The vertical analysis filter used to decompose this subband,
105        from its childs. This is applicable to "node" elements
106        only. The default value is null. */
107    public SynWTFilter vFilter;
108
109    /** The number of magnitude bits */
110    public int magbits = 0;
111
112    /**
113     * Creates a SubbandSyn element with all the default values. The
114     * dimensions are (0,0) and the upper left corner is (0,0).
115     *
116     *
117     * */
118    public SubbandSyn() {
119    }
120
121    /**
122     * Creates the top-level node and the entire subband tree, with
123     * the top-level dimensions, the number of decompositions, and the
124     * decomposition tree as specified.
125     *
126     * <P>This constructor just calls the same constructor of the
127     * super class.
128     *
129     * @param w The top-level width
130     *
131     * @param h The top-level height
132     *
133     * @param ulcx The horizontal coordinate of the upper-left corner with
134     * respect to the canvas origin, in the component grid.
135     *
136     * @param ulcy The vertical  coordinate of the upper-left corner with
137     * respect to the canvas origin, in the component grid.
138     *
139     * @param lvls The number of levels (or LL decompositions) in the
140     * tree.
141     *
142     * @param hfilters The horizontal wavelet synthesis filters for each
143     * resolution level, starting at resolution level 0.
144     *
145     * @param vfilters The vertical wavelet synthesis filters for each
146     * resolution level, starting at resolution level 0.
147     *
148     * @see Subband#Subband(int,int,int,int,int,
149     * WaveletFilter[],WaveletFilter[])
150     *
151     *
152     * */
153    public SubbandSyn(int w, int h, int ulcx, int ulcy, int lvls,
154                     WaveletFilter hfilters[], WaveletFilter vfilters[]) {
155        super(w,h,ulcx,ulcy,lvls,hfilters,vfilters);
156    }
157
158    /**
159     * Returns the parent of this subband. The parent of a subband is
160     * the subband from which this one was obtained by
161     * decomposition. The root element has no parent subband (null).
162     *
163     * @return The parent subband, or null for the root one.
164     *
165     *
166     * */
167    public Subband getParent() {
168        return parent;
169    }
170
171    /**
172     * Returns the LL child subband of this subband.
173     *
174     * @return The LL child subband, or null if there are no childs.
175     *
176     *
177     * */
178    public Subband getLL() {
179        return subb_LL;
180    }
181
182    /**
183     * Returns the HL (horizontal high-pass) child subband of this
184     * subband.
185     *
186     * @return The HL child subband, or null if there are no childs.
187     *
188     *
189     * */
190    public Subband getHL() {
191        return subb_HL;
192    }
193
194    /**
195     * Returns the LH (vertical high-pass) child subband of this
196     * subband.
197     *
198     * @return The LH child subband, or null if there are no childs.
199     *
200     *
201     * */
202    public Subband getLH() {
203        return subb_LH;
204    }
205
206    /**
207     * Returns the HH child subband of this subband.
208     *
209     * @return The HH child subband, or null if there are no childs.
210     *
211     *
212     * */
213    public Subband getHH() {
214        return subb_HH;
215    }
216
217    /**
218     * Splits the current subband in its four subbands. It changes the
219     * status of this element (from a leaf to a node, and sets the
220     * filters), creates the childs and initializes them. An
221     * IllegalArgumentException is thrown if this subband is not a
222     * leaf.
223     *
224     * <P>It uses the initChilds() method to initialize the childs.
225     *
226     * @param hfilter The horizontal wavelet filter used to decompose
227     * this subband. It has to be a SynWTFilter object.
228     *
229     * @param vfilter The vertical wavelet filter used to decompose this
230     * subband. It has to be a SynWTFilter object.
231     *
232     * @return  A reference to the LL leaf (subb_LL).
233     *
234     * @see Subband#initChilds
235     *
236     *
237     * */
238    protected Subband split(WaveletFilter hfilter, WaveletFilter vfilter) {
239        // Test that this is a node
240        if (isNode) {
241            throw new IllegalArgumentException();
242        }
243
244        // Modify this element into a node and set the filters
245        isNode = true;
246        this.hFilter = (SynWTFilter) hfilter;
247        this.vFilter = (SynWTFilter) vfilter;
248
249        // Create childs
250        subb_LL = new SubbandSyn();
251        subb_LH = new SubbandSyn();
252        subb_HL = new SubbandSyn();
253        subb_HH = new SubbandSyn();
254
255        // Assign parent
256        subb_LL.parent = this;
257        subb_HL.parent = this;
258        subb_LH.parent = this;
259        subb_HH.parent = this;
260
261        // Initialize childs
262        initChilds();
263
264        // Return reference to LL subband
265        return subb_LL;
266    }
267    /**
268     * This function returns the horizontal wavelet filter relevant to this
269     * subband
270     *
271     * @return The horizontal wavelet filter
272     *
273     *
274     */
275    public WaveletFilter getHorWFilter(){
276        return hFilter;
277    }
278
279    /**
280     * This function returns the vertical wavelet filter relevant to this
281     * subband
282     *
283     * @return The vertical wavelet filter
284     *
285     *
286     */
287    public WaveletFilter getVerWFilter(){
288        return hFilter;
289    }
290
291}