001/* 002 * $RCSfile: SubbandAn.java,v $ 003 * $Revision: 1.1 $ 004 * $Date: 2005/02/11 05:02:31 $ 005 * $State: Exp $ 006 * 007 * Class: SubbandAn 008 * 009 * Description: Element for a tree structure for a descripotion 010 * of subbands on the anslysis 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.analysis; 051 052import jj2000.j2k.wavelet.Subband; 053import jj2000.j2k.wavelet.WaveletFilter; 054 055/** 056 * This class represents a subband in a bidirectional tree structure 057 * that describes the subband decomposition for a wavelet transform, 058 * specifically for the analysis 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 SubbandAn 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 SubbandAn parent = null; 075 076 /** 077 * The reference to the LL subband resulting from the 078 * decomposition of this subband. It is null by default. */ 079 public SubbandAn 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 SubbandAn 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 SubbandAn 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 SubbandAn subb_HH; 098 099 /** The horizontal analysis filter used to decompose this 100 subband. This is applicable to "node" elements only. The 101 default value is null. */ 102 public AnWTFilter hFilter; 103 104 /** The vertical analysis filter used to decompose this 105 subband. This is applicable to "node" elements only. The 106 default value is null. */ 107 public AnWTFilter vFilter; 108 109 /** 110 * The L2-norm of the synthesis basis waveform of this subband, 111 * applicable to "leafs" only. By default it is -1 (i.e. not 112 * calculated yet). 113 * */ 114 public float l2Norm = -1.0f; 115 116 /** 117 * The contribution to the MSE or WMSE error that would result in the 118 * image if there was an error of exactly one quantization step size in 119 * the sample of the subband. This value is expressed relative to a 120 * nominal dynamic range in the image domain of exactly 1.0. This field 121 * contains valid data only after quantization 9See Quantizer). 122 * 123 * @see jj2000.j2k.quantization.quantizer.Quantizer 124 * */ 125 public float stepWMSE; 126 127 /** 128 * Creates a SubbandAn element with all the default values. The 129 * dimensions are (0,0) and the upper left corner is (0,0). 130 * 131 * 132 * */ 133 public SubbandAn() { 134 } 135 136 /** 137 * Creates the top-level node and the entire subband tree, with 138 * the top-level dimensions, the number of decompositions, and the 139 * decomposition tree as specified. 140 * 141 * <P>This constructor just calls the same constructor of the 142 * super class, and then calculates the L2-norm (or energy weight) 143 * of each leaf. 144 * 145 * <P>This constructor does not initialize the value of the magBits or 146 * stepWMSE member variables. This variables are normally initialized by 147 * the quantizer (see Quantizer). 148 * 149 * @param w The top-level width 150 * 151 * @param h The top-level height 152 * 153 * @param ulcx The horizontal coordinate of the upper-left corner with 154 * respect to the canvas origin, in the component grid. 155 * 156 * @param ulcy The vertical coordinate of the upper-left corner with 157 * respect to the canvas origin, in the component grid. 158 * 159 * @param lvls The number of levels (or LL decompositions) in the 160 * tree. 161 * 162 * @param hfilters The horizontal wavelet analysis filters for each 163 * resolution level, starting at resolution level 0. 164 * 165 * @param vfilters The vertical wavelet analysis filters for each 166 * resolution level, starting at resolution level 0. 167 * 168 * @see Subband#Subband(int,int,int,int,int, 169 * WaveletFilter[],WaveletFilter[]) 170 * 171 * @see jj2000.j2k.quantization.quantizer.Quantizer 172 * 173 * 174 * */ 175 public SubbandAn(int w, int h, int ulcx, int ulcy, int lvls, 176 WaveletFilter hfilters[], WaveletFilter vfilters[]) { 177 super(w,h,ulcx,ulcy,lvls,hfilters,vfilters); 178 // Caculate the L2-norms 179 calcL2Norms(); 180 } 181 182 /** 183 * Returns the parent of this subband. The parent of a subband is 184 * the subband from which this one was obtained by 185 * decomposition. The root element has no parent subband (null). 186 * 187 * @return The parent subband, or null for the root one. 188 * 189 * 190 * */ 191 public Subband getParent() { 192 return parent; 193 } 194 195 /** 196 * Returns the LL child subband of this subband. 197 * 198 * @return The LL child subband, or null if there are no childs. 199 * 200 * 201 * */ 202 public Subband getLL() { 203 return subb_LL; 204 } 205 206 /** 207 * Returns the HL (horizontal high-pass) child subband of this 208 * subband. 209 * 210 * @return The HL child subband, or null if there are no childs. 211 * 212 * 213 * */ 214 public Subband getHL() { 215 return subb_HL; 216 } 217 218 /** 219 * Returns the LH (vertical high-pass) child subband of this 220 * subband. 221 * 222 * @return The LH child subband, or null if there are no childs. 223 * 224 * 225 * */ 226 public Subband getLH() { 227 return subb_LH; 228 } 229 230 /** 231 * Returns the HH child subband of this subband. 232 * 233 * @return The HH child subband, or null if there are no childs. 234 * 235 * 236 * */ 237 public Subband getHH() { 238 return subb_HH; 239 } 240 241 /** 242 * Splits the current subband in its four subbands. It changes the 243 * status of this element (from a leaf to a node, and sets the 244 * filters), creates the childs and initializes them. An 245 * IllegalArgumentException is thrown if this subband is not a 246 * leaf. 247 * 248 * <P>It uses the initChilds() method to initialize the childs. 249 * 250 * @param hfilter The horizontal wavelet filter used to decompose 251 * this subband. It has to be a AnWTFilter object. 252 * 253 * @param vfilter The vertical wavelet filter used to decompose this 254 * subband. It has to be a AnWTFilter object. 255 * 256 * @return A reference to the LL leaf (subb_LL). 257 * 258 * @see Subband#initChilds 259 * 260 * 261 * */ 262 protected Subband split(WaveletFilter hfilter, WaveletFilter vfilter) { 263 // Test that this is a node 264 if (isNode) { 265 throw new IllegalArgumentException(); 266 } 267 268 // Modify this element into a node and set the filters 269 isNode = true; 270 this.hFilter = (AnWTFilter) hfilter; 271 this.vFilter = (AnWTFilter) vfilter; 272 273 // Create childs 274 subb_LL = new SubbandAn(); 275 subb_LH = new SubbandAn(); 276 subb_HL = new SubbandAn(); 277 subb_HH = new SubbandAn(); 278 279 // Assign parent 280 subb_LL.parent = this; 281 subb_HL.parent = this; 282 subb_LH.parent = this; 283 subb_HH.parent = this; 284 285 // Initialize childs 286 initChilds(); 287 288 // Return reference to LL subband 289 return subb_LL; 290 } 291 292 /** 293 * Calculates the basis waveform of the first leaf for which the 294 * L2-norm has not been calculated yet. This method searches 295 * recursively for the first leaf for which the value has not been 296 * calculated yet, and then calculates the L2-norm on the return 297 * path. 298 * 299 * <P>The wfs argument should be a size 2 array of float arrays 300 * (i.e. 2D array) and it must be of length 2 (or more). When 301 * returning, wfs[0] will contain the line waveform, and wfs[1] 302 * will contain the column waveform. 303 * 304 * <P>This method can not be called on an element that ahs a 305 * non-negative value in l2Norm, since that means that we are 306 * done. 307 * 308 * @param wfs An size 2 array where the line and column waveforms 309 * will be returned. 310 * 311 * 312 * */ 313 private void calcBasisWaveForms(float wfs[][]) { 314 if (l2Norm < 0) { 315 // We are not finished with this element yet 316 if (isNode) { 317 // We are on a node => search on childs 318 if (subb_LL.l2Norm < 0f) { 319 subb_LL.calcBasisWaveForms(wfs); 320 wfs[0] = 321 hFilter.getLPSynWaveForm(wfs[0],null); 322 wfs[1] = 323 vFilter.getLPSynWaveForm(wfs[1],null); 324 } 325 else if (subb_HL.l2Norm < 0f) { 326 subb_HL.calcBasisWaveForms(wfs); 327 wfs[0] = 328 hFilter.getHPSynWaveForm(wfs[0],null); 329 wfs[1] = 330 vFilter.getLPSynWaveForm(wfs[1],null); 331 } 332 else if (subb_LH.l2Norm < 0f) { 333 subb_LH.calcBasisWaveForms(wfs); 334 wfs[0] = 335 hFilter.getLPSynWaveForm(wfs[0],null); 336 wfs[1] = 337 vFilter.getHPSynWaveForm(wfs[1],null); 338 } 339 else if (subb_HH.l2Norm < 0f) { 340 subb_HH.calcBasisWaveForms(wfs); 341 wfs[0] = 342 hFilter.getHPSynWaveForm(wfs[0],null); 343 wfs[1] = 344 vFilter.getHPSynWaveForm(wfs[1],null); 345 } 346 else { 347 // There is an error! If all childs have 348 // non-negative l2norm, then this node should have 349 // non-negative l2norm 350 throw new Error("You have found a bug in JJ2000!"); 351 } 352 } 353 else { 354 // This is a leaf, just use diracs (null is 355 // equivalent to dirac) 356 wfs[0] = new float[1]; 357 wfs[0][0] = 1.0f; 358 wfs[1] = new float[1]; 359 wfs[1][0] = 1.0f; 360 } 361 362 } 363 else { 364 // This is an error! The calcBasisWaveForms() method is 365 // never called on an element with non-negative l2norm 366 throw new Error("You have found a bug in JJ2000!"); 367 } 368 } 369 370 /** 371 * Assigns the given L2-norm to the first leaf that does not have 372 * an L2-norm value yet (i.e. l2norm is negative). The search is 373 * done recursively and in the same order as that of the 374 * calcBasisWaveForms() method, so that this method is used to 375 * assigne the l2norm of the previously computed waveforms. 376 * 377 * <P>This method can not be called on an element that ahs a 378 * non-negative value in l2Norm, since that means that we are 379 * done. 380 * 381 * @param l2n The L2-norm to assign. 382 * 383 * 384 * */ 385 private void assignL2Norm(float l2n) { 386 if (l2Norm < 0) { 387 // We are not finished with this element yet 388 if (isNode) { 389 // We are on a node => search on childs 390 if (subb_LL.l2Norm < 0f) { 391 subb_LL.assignL2Norm(l2n); 392 } 393 else if (subb_HL.l2Norm < 0f) { 394 subb_HL.assignL2Norm(l2n); 395 } 396 else if (subb_LH.l2Norm < 0f) { 397 subb_LH.assignL2Norm(l2n); 398 } 399 else if (subb_HH.l2Norm < 0f) { 400 subb_HH.assignL2Norm(l2n); 401 // If child now is done, we are done 402 if (subb_HH.l2Norm >= 0f) { 403 l2Norm = 0f; // We are on a node, any non-neg value OK 404 } 405 } 406 else { 407 // There is an error! If all childs have 408 // non-negative l2norm, then this node should have 409 // non-negative l2norm 410 throw new Error("You have found a bug in JJ2000!"); 411 } 412 } 413 else { 414 // This is a leaf, assign the L2-norm 415 l2Norm = l2n; 416 } 417 418 } 419 else { 420 // This is an error! The assignL2Norm() method is 421 // never called on an element with non-negative l2norm 422 throw new Error("You have found a bug in JJ2000!"); 423 } 424 } 425 426 427 /** 428 * Calculates the L2-norm of the sythesis waveforms of every leaf 429 * in the tree. This method should only be called on the root 430 * element. 431 * 432 * 433 * */ 434 private void calcL2Norms() { 435 int i; 436 float wfs[][] = new float[2][]; 437 double acc; 438 float l2n; 439 440 // While we are not done on the root element, compute basis 441 // functions and assign L2-norm 442 while (l2Norm < 0f) { 443 calcBasisWaveForms(wfs); 444 // Compute line L2-norm, which is the product of the line 445 // and column L2-norms 446 acc = 0.0; 447 for (i=wfs[0].length-1; i>=0; i--) { 448 acc += wfs[0][i]*wfs[0][i]; 449 } 450 l2n = (float) Math.sqrt(acc); 451 // Compute column L2-norm 452 acc = 0.0; 453 for (i=wfs[1].length-1; i>=0; i--) { 454 acc += wfs[1][i]*wfs[1][i]; 455 } 456 l2n *= (float) Math.sqrt(acc); 457 // Release waveforms 458 wfs[0] = null; 459 wfs[1] = null; 460 // Assign the value 461 assignL2Norm(l2n); 462 } 463 } 464 465 /** 466 * This function returns the horizontal wavelet filter relevant to this 467 * subband 468 * 469 * @return The horizontal wavelet filter 470 * 471 * 472 */ 473 public WaveletFilter getHorWFilter(){ 474 return hFilter; 475 } 476 477 /** 478 * This function returns the vertical wavelet filter relevant to this 479 * subband 480 * 481 * @return The vertical wavelet filter 482 * 483 * 484 */ 485 public WaveletFilter getVerWFilter(){ 486 return hFilter; 487 } 488}