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📄 qccwavliftinganalysisint.3

📁 spiht for linux this is used to decod and encode vedio i wich all enjoy
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.TH QCCWAVLIFTINGANALYSISINT 3 "QCCPACK" "".SH NAMEQccWAVLiftingAnalysisInt, QccWAVLiftingSynthesisInt \- perform integer-valued lifting analysis/synthesis of a signal.SH SYNOPSISINT.B #include "libQccPack.h".sp.BI "int QccWAVLiftingAnalysisInt(QccVectorInt " signal ", int " signal_length ", int " phase ", const QccWAVLiftingScheme *" lifting_scheme ", int " boundary );.br.BI "int QccWAVLiftingSynthesisInt(QccVectorInt " signal ", int " signal_length ", int " phase ", const QccWAVLiftingScheme *" lifting_scheme ", int " boundary );.SH DESCRIPTION.B QccWAVLiftingAnalysisInt()performs one level of aninteger-valued wavelet decomposition,which maps integer signal values into integer-valued wavelet coefficients(see "INTEGER-TO-INTEGER WAVELET TRANSFORMS" below).Specifically,lifting analysis is employed to produce a lowpass subbandand a highpass subband of.IR signal .The lowpass subband is returned as thefirst half of.IR signal ;the highpass subband is returned as the last half of.IR signal ..I signal_lengthgives the length of.I signaland may be even or odd..LPIf.I phaseis.BR QCCWAVWAVELET_PHASE_EVEN ,then.I signalis assumed to start with a even-indexed sample.Otherwise, if.I phaseis.BR QCCWAVWAVELET_PHASE_ODD ,it indicates that.I signalstarts with an odd-indexed sample..I phaseis passed to.BR QccWAVWaveletLWTInt (3),the lazy wavelet transform,the first step of lifting analysis, to indicate thesignal origin..LPIn the case that.I signal_lengthis even, both the odd and even subbands of produced by lifting analysisare the same length.  On the other hand, if.I signal_lengthis odd, one of the two subbands will be one sample longerthan the other. Which subband will be longer will depend onthe value of.IR phase .Specifically, if.IR phaseis.BR QCCWAVWAVELET_PHASE_EVEN ,then the lowpass subband is one sample longer than the highpasssubband. If.IR phaseis.BR QCCWAVWAVELET_PHASE_ODD ,the the highpass subband is one sample longer than the lowpasssubband..LP.I lifting_schemegives the particular lifting scheme to employ,which must be an integer-valued lifting scheme.Lifting implementations ofwavelet analysis and synthesis are "hard-coded" into the QccPack libraryfor purposes of execution speed and ease of implementation.As a consequence, only a limited number of waveletsare current supported, and this list cannot be extended by the user(without modifying the QccPack source code, or course).The currently supported integer-valued lifting schemes and their corresponding.B LFTfiles (see.BR QccWAVLiftingScheme (3))are.RSLWT.int.lft - integer-valued Lazy Wavelet transform.brCohenDaubechiesFeauveau.9-7.int.lft - integer-valued 9/7 biorthogonal wavelet.brCohenDaubechiesFeauveau.5-3.int.lft - integer-valued 5/3 biorthogonal wavelet.RE.LP.B QccWAVLiftingSynthesisInt()performs one level of wavelet synthesis.  The first half of.I signalis assumed to contain the lowpass subband while the second half containsthe highpass subband.Lifting synthesis is performedto produce the output signal which is returned in.IR signal ,including a call to.BR QccWAVWaveletInverseLWTInt (3)to perform an inverse lazy wavelet transform.As with.BR QccWAVLiftingAnalysisInt() ,.I signal_lengthmay be even or odd..I phaseindicates whether the output.I signalis to start with an even- or odd-indexed sample..LP.IR boundaryindicates how lifting should be handled at the ends of the signal andcan be one of the following:.B QCCWAVWAVELET_BOUNDARY_SYMMETRIC_EXTENSION(symmetric extension, valid only for biorthogonal wavelets), or.B QCCWAVWAVELET_BOUNDARY_PERIODIC_EXTENSION(periodic extension, valid for orthogonal and biorthogonal wavelets).Check the comments at the start of each.B LFTfile for permitted values for.I boundaryfor particular lifting schemes.Note that, if periodic extension is used,.IR signal_lengthmust be even (this is due to mathematical constraints)..LPThe case in which.IR signal_lengthis equal to 1 is degenerate. A wavelet transform is technically not welldefined for this situation because it is not clear how to subsamplethe signal. For integer-valued lifting in QccPack, the length-one signal ismerely placed in the lowpass subband unchanged (in whichcase the highpass subband has zero length) for .IR phaseequal to.BR QCCWAVWAVELET_PHASE_EVEN ,or placed in the highpass subband unchanged(in which case the lowpass subband has zero length) for.IR phaseequal to.BR QCCWAVWAVELET_PHASE_ODD ..LPNote:In general, you will probably want to use.BR QccWAVWaveletDWT1DInt (3)and.BR QccWAVWaveletInverseDWT1DInt (3)instead of these routinesfor implementing a discrete wavelet transform and its inverse since.BR QccWAVWaveletDWT1DInt (3)and.BR QccWAVWaveletInverseDWT1DInt (3)allow any number of scales, or levels, of decomposition to beperformed..SH "INTEGER-TO-INTEGER WAVELET TRANSFORMS"Transforms generally provide perfect reconstruction in that theinverse transform will perfectly invert transform coefficientsinto an exact representation of the original signal.However, when implemented in floating-point arithmetic, the potentialfor loss arises due to the limits of finite precision in both theforward and inverse transforms.On the other hand,transforms that map integer-valued signals into integer-valuedtransforms coefficients can guarantee perfect reconstruction, providedan inverse transform can be found.For this reason, lifting schemes, in which inverse transforms aretrivial, are favored for theimplementation of integer-valued wavelet transforms. Typically,the general approach proposed by Calderbank.IR "et al" .is followed wherein rounding of floating-point values to integers is performedat each prediction and update step in a lifting scheme.Integer versions of several popular biorthogonal wavelets werecreated in this manner by Calderbank.IR "et al" .,as well as by Xiong.IR "et al" ..LPIn traditional floating-point lifting, the prediction and update stepsare generally followed by a single application of scaling by a constantin order to produce the usual unitary normalization.This scaling step is somewhat problematic for integer-valued liftingsince the scaling constant is usually not an integer.In applications wherein unitary scaling is not required(e.g., in some applications that process each subband completelyindependently), the scaling step is simply dropped in orderto implement an integer-valued version of the transform.Alternatively, one can append three additional lifting steps to implement the scaling; these additional lifting steps can then be renderedinteger-valued via appropriate rounding (e.g., Xiong.IR "et al" .)making the transforms approximately normalized.This latter approach of scaling via additional lifting stepsis employed in the integer-valuedlifting schemes implemented in QccPack..SH "RETURN VALUES"These routinesreturn 0 on success and 1 on error..SH "SEE ALSO".BR QccWAVLiftingScheme (3),.BR QccWAVWavelet (3),.BR QccWAVWaveletDWT1DInt (3),.BR QccWAVWaveletInverseDWT1DInt (3),.BR QccPackWAV (3),.BR QccPack (3).LPA. R. Calderbank, I. Daubechies, W. Sweldens, B.-L. Yeo, "LosslessImage Compression Using Integer to Integer Wavelet Transforms", in.IR "Proceedings of the International Conference on Image Processing" ,Lausanne, Switzerland, pp. 596-599, September 1997.Z. Xiong, X. Wu, S. Cheng, J. Hua, "Lossy-to-Lossless Compression ofMedical Volumetric Data Using Three-Dimensional Integer Wavelet Transforms,".IR "IEEE Transactions on Medical Imaging" ,vol. 22, pp. 459-470, March 2003.I. Daubechies and W. Sweldens,"Factoring Wavelet Transforms Into Lifting Steps,".IR "J. Fourier Anal. Appl." ,vol. 4, no. 3, pp. 245-267, 1998..SH AUTHORCopyright (C) 1997-2009  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.

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