Mercurial > hg > smallbox
view util/Rice Wavelet Toolbox/mdwt.mhelp @ 197:d00e97b2f1cb luisf_dev
Fixed path reference to the current folder in SMALLBoxSetup.
author | luisf <luis.figueira@eecs.qmul.ac.uk> |
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date | Tue, 20 Mar 2012 10:40:59 +0000 |
parents | f69ae88b8be5 |
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function [y,L] = mdwt(x,h,L); % [y,L] = mdwt(x,h,L); % % Function computes the discrete wavelet transform y for a 1D or 2D input % signal x using the scaling filter h. % % Input: % x : finite length 1D or 2D signal (implicitly periodized) % h : scaling filter % L : number of levels. In the case of a 1D signal, length(x) must be % divisible by 2^L; in the case of a 2D signal, the row and the % column dimension must be divisible by 2^L. If no argument is % specified, a full DWT is returned for maximal possible L. % % Output: % y : the wavelet transform of the signal % (see example to understand the coefficients) % L : number of decomposition levels % % 1D Example: % x = makesig('LinChirp',8); % h = daubcqf(4,'min'); % L = 2; % [y,L] = mdwt(x,h,L) % % 1D Example's output and explanation: % % y = [1.1097 0.8767 0.8204 -0.5201 -0.0339 0.1001 0.2201 -0.1401] % L = 2 % % The coefficients in output y are arranged as follows % % y(1) and y(2) : Scaling coefficients (lowest frequency) % y(3) and y(4) : Band pass wavelet coefficients % y(5) to y(8) : Finest scale wavelet coefficients (highest frequency) % % 2D Example: % % load test_image % h = daubcqf(4,'min'); % L = 1; % [y,L] = mdwt(test_image,h,L); % % 2D Example's output and explanation: % % The coefficients in y are arranged as follows. % % .------------------. % | | | % | 4 | 2 | % | | | % | L,L | H,L | % | | | % -------------------- % | | | % | 3 | 1 | % | | | % | L,H | H,H | % | | | % `------------------' % % where % 1 : High pass vertically and high pass horizontally % 2 : Low pass vertically and high pass horizontally % 3 : High pass vertically and low pass horizontally % 4 : Low pass vertically and Low pass horizontally % (scaling coefficients) % % % % % See also: midwt, mrdwt, mirdwt % %File Name: mdwt.m %Last Modification Date: 08/07/95 15:13:25 %Current Version: mdwt.m 2.4 %File Creation Date: Wed Oct 19 10:51:58 1994 %Author: Markus Lang <lang@jazz.rice.edu> % %Copyright (c) 2000 RICE UNIVERSITY. All rights reserved. %Created by Markus Lang, Department of ECE, Rice University. % %This software is distributed and licensed to you on a non-exclusive %basis, free-of-charge. Redistribution and use in source and binary forms, %with or without modification, are permitted provided that the following %conditions are met: % %1. Redistribution of source code must retain the above copyright notice, % this list of conditions and the following disclaimer. %2. Redistribution in binary form must reproduce the above copyright notice, % this list of conditions and the following disclaimer in the % documentation and/or other materials provided with the distribution. %3. All advertising materials mentioning features or use of this software % must display the following acknowledgment: This product includes % software developed by Rice University, Houston, Texas and its contributors. %4. Neither the name of the University nor the names of its contributors % may be used to endorse or promote products derived from this software % without specific prior written permission. % %THIS SOFTWARE IS PROVIDED BY WILLIAM MARSH RICE UNIVERSITY, HOUSTON, TEXAS, %AND CONTRIBUTORS AS IS AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, %BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS %FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RICE UNIVERSITY %OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, %EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, %PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; %OR BUSINESS INTERRUPTIONS) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, %WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR %OTHERWISE), PRODUCT LIABILITY, OR OTHERWISE ARISING IN ANY WAY OUT OF THE %USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. % %For information on commercial licenses, contact Rice University's Office of %Technology Transfer at techtran@rice.edu or (713) 348-6173 % %Change History: % %Modification #1 %Mon Aug 7 11:42:11 CDT 1995 %Rebecca Hindman <hindman@ece.rice.edu> %Added L to function line so that it can be displayed as an output % %Change History: % %Modification #1 %Thu Mar 2 13:07:11 CDT 2000 %Ramesh Neelamani<neelsh@ece.rice.edu> %Revamped the help file %