.TH QCCWAVWAVELETSHAPEADAPTIVEDWT2D 3 "QCCPACK" "".SH NAMEQccWAVWaveletShapeAdaptiveDWT2D, QccWAVWaveletInverseShapeAdaptiveDWT2D \- separable 2D shape-adaptive discretewavelet transform and inverse transform for a 2D signal.SH SYNOPSIS.B #include "libQccPack.h".sp.BI "int QccWAVWaveletShapeAdaptiveDWT2D(const QccMatrix " input_data ", QccMatrix " input_mask ", QccMatrix " output_data ", QccMatrix " output_mask ", int " num_rows ", int " num_cols ", int " num_scales ", const QccWAVWavelet *" wavelet );.sp.BI "int QccWAVWaveletInverseShapeAdaptiveDWT2D(const QccMatrix " input_data ", QccMatrix " input_mask ", QccMatrix " output_data ", QccMatrix " output_mask ", int " num_rows ", int " num_cols ", int " num_scales ", const QccWAVWavelet *" wavelet );.SH DESCRIPTION.B QccWAVWaveletShapeAdaptiveDWT2D()performs a separable 2Dshape-adaptive discrete wavelet transform (SA-DWT) of a two-dimensional signal,.IR input_data ,which is represented as a matrix of.I num_rowsrows and.I num_colscolumns..I num_scalesgives the number of scales, or levels, of the decomposition..BR QccWAVWaveletShapeAdaptiveDWT2D()implements a dyadic decomposition of.IR input_data ;that is, the low-low subband (baseband)is recursively decomposed into a lowpass andthree highpass bands for each level of decomposition..I output_datacontains the output of the DWT;the subbands reside in .I output_datawith the baseband in the upper-left corner, with highpass subbandssuccessively "nested" from the upper-left corner to lower-right corner..LP.I input_maskindicates where.I input_dataexists. That is, .I input_maskindicates the regions of support of.IR input_data .Where.I input_maskis less than or equal to.BR QCCALPHA_TRANSPARENT ,there is no data, and where.I input_maskis greater than.BR QCCALPHA_TRANSPARENT ,data exists and is transformed(see.BR QccAlpha (3))..LPEssentially, the 2D SA-DWT is implemented by doing one scale of a1D SA-DWT for each row, and then for each column.See .BR QccWAVWaveletShapeAdaptiveDWT1D (3)for specific details on how this 1D SA-DWT is calculated..LPThe transparency mask is transformed (with a 2D Lazy wavelet transform)alongside the data so that.IR output_maskindicates where valid coefficients, i.e., coefficients resulting fromnon-transparent regions in.IR input_data ,reside in.IR output_data ..LPCurrently, .BR QccWAVWaveletShapeAdaptiveDWT1D()supports only biorthogonal wavelets. These may beused with symmetric extension (lifting or filter-bankimplementations) or boundary-wavelet extension(lifting implementations only)..LP.B QccWAVWaveletInverseShapeAdaptiveDWT2D()performs the corresponding separable 2D inverse SA-DWT of.IR input_datawhich is assumed to have been producedby.BR QccWAVWaveletShapeAdaptiveDWT2D() ..IR input_maskshould be the corresponding Lazy-wavelet transformed maskalso produced by.BR QccWAVWaveletShapeAdaptiveDWT2D() ..I num_scalesgives the number of levels of decomposition that exist in.IR input_data ..LPFor both.BR QccWAVWaveletShapeAdaptiveDWT2D()and.BR QccWAVWaveletInverseShapeAdaptiveDWT2D() ,sufficient space for.I output_dataand.I output_maskmust be allocated prior to callingthe routines..LPUse.BR QccWAVSubbandPyramidShapeAdaptiveDWT (3)and.BR QccWAVSubbandPyramidInverseShapeAdaptiveDWT (3)to perform a 2D separable SA-DWT or inverse SA-DWT on a.B QccWAVSubbandPyramiddata structure (which is the recommended way to do it, since the.B QccWAVSubbandPyramidstructure stores the number of levels of decomposition along withthe transform coefficients)..SH "RETURN VALUES"These routinesreturn 0 on success and 1 on error..SH "NOTES"SA-DWTs have been recently included in Version 2 of the MPEG-4standard, wherein they are used for texture coding of arbitrarily shaped still objects.Li and Li (see below) elaborate at length on the shape-adaptive DWTused in MPEG-4, and also consider some variants not includedin the MPEG-4 standard.See .BR QccWAVWaveletShapeAdaptiveDWT1D (3)for details on the differences between the QccPack SA-DWT implementation,the MPEG-4 specification, and Li and Li's descriptions..SH "SEE ALSO".BR QccWAVWaveletShapeAdaptiveDWT1D (3),.BR QccWAVWaveletInverseShapeAdaptiveDWT1D (3),.BR QccWAVSubbandPyramidShapeAdaptiveDWT (3),.BR QccWAVSubbandPyramidInverseShapeAdaptiveDWT (3),.BR QccWAVWavelet (3),.BR QccPackWAV (3),.BR QccPack (3).LPS. Li and W. Li, "Shape-Adaptive Discrete Wavelet Transforms forArbitrarily Shaped Visual Object Coding,".IR "IEEE Transactions on Circuits and Systems for Video Coding" ,vol. 10, pp. 725-743, August 2000..LPISO/IEC 14496-2, "Information Technology -- Coding of audio-visual objects --Part 2: Visual," .IR "MPEG-4 Standard" ,Amendment 1, July 2000..SH AUTHORCopyright (C) 1997-2005  James E. Fowler.\"  The programs herein are free software; you can redistribute them an.or.\"  modify them under the terms of the GNU General Public License.\"  as published by the Free Software Foundation; either version 2.\"  of the License, or (at your option) any later version..\"  .\"  These programs are distributed in the hope that they will be useful,.\"  but WITHOUT ANY WARRANTY; without even the implied warranty of.\"  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the.\"  GNU General Public License for more details..\"  .\"  You should have received a copy of the GNU General Public License.\"  along with these programs; if not, write to the Free Software.\"  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.