annotate util/Rice Wavelet Toolbox/mdwt.mhelp @ 81:a30e8bd6d948

matlab_midi scripts
author Ivan <ivan.damnjanovic@eecs.qmul.ac.uk>
date Mon, 28 Mar 2011 17:35:01 +0100
parents f69ae88b8be5
children
rev   line source
ivan@78 1 function [y,L] = mdwt(x,h,L);
ivan@78 2 % [y,L] = mdwt(x,h,L);
ivan@78 3 %
ivan@78 4 % Function computes the discrete wavelet transform y for a 1D or 2D input
ivan@78 5 % signal x using the scaling filter h.
ivan@78 6 %
ivan@78 7 % Input:
ivan@78 8 % x : finite length 1D or 2D signal (implicitly periodized)
ivan@78 9 % h : scaling filter
ivan@78 10 % L : number of levels. In the case of a 1D signal, length(x) must be
ivan@78 11 % divisible by 2^L; in the case of a 2D signal, the row and the
ivan@78 12 % column dimension must be divisible by 2^L. If no argument is
ivan@78 13 % specified, a full DWT is returned for maximal possible L.
ivan@78 14 %
ivan@78 15 % Output:
ivan@78 16 % y : the wavelet transform of the signal
ivan@78 17 % (see example to understand the coefficients)
ivan@78 18 % L : number of decomposition levels
ivan@78 19 %
ivan@78 20 % 1D Example:
ivan@78 21 % x = makesig('LinChirp',8);
ivan@78 22 % h = daubcqf(4,'min');
ivan@78 23 % L = 2;
ivan@78 24 % [y,L] = mdwt(x,h,L)
ivan@78 25 %
ivan@78 26 % 1D Example's output and explanation:
ivan@78 27 %
ivan@78 28 % y = [1.1097 0.8767 0.8204 -0.5201 -0.0339 0.1001 0.2201 -0.1401]
ivan@78 29 % L = 2
ivan@78 30 %
ivan@78 31 % The coefficients in output y are arranged as follows
ivan@78 32 %
ivan@78 33 % y(1) and y(2) : Scaling coefficients (lowest frequency)
ivan@78 34 % y(3) and y(4) : Band pass wavelet coefficients
ivan@78 35 % y(5) to y(8) : Finest scale wavelet coefficients (highest frequency)
ivan@78 36 %
ivan@78 37 % 2D Example:
ivan@78 38 %
ivan@78 39 % load test_image
ivan@78 40 % h = daubcqf(4,'min');
ivan@78 41 % L = 1;
ivan@78 42 % [y,L] = mdwt(test_image,h,L);
ivan@78 43 %
ivan@78 44 % 2D Example's output and explanation:
ivan@78 45 %
ivan@78 46 % The coefficients in y are arranged as follows.
ivan@78 47 %
ivan@78 48 % .------------------.
ivan@78 49 % | | |
ivan@78 50 % | 4 | 2 |
ivan@78 51 % | | |
ivan@78 52 % | L,L | H,L |
ivan@78 53 % | | |
ivan@78 54 % --------------------
ivan@78 55 % | | |
ivan@78 56 % | 3 | 1 |
ivan@78 57 % | | |
ivan@78 58 % | L,H | H,H |
ivan@78 59 % | | |
ivan@78 60 % `------------------'
ivan@78 61 %
ivan@78 62 % where
ivan@78 63 % 1 : High pass vertically and high pass horizontally
ivan@78 64 % 2 : Low pass vertically and high pass horizontally
ivan@78 65 % 3 : High pass vertically and low pass horizontally
ivan@78 66 % 4 : Low pass vertically and Low pass horizontally
ivan@78 67 % (scaling coefficients)
ivan@78 68 %
ivan@78 69 %
ivan@78 70 %
ivan@78 71 %
ivan@78 72 % See also: midwt, mrdwt, mirdwt
ivan@78 73 %
ivan@78 74
ivan@78 75 %File Name: mdwt.m
ivan@78 76 %Last Modification Date: 08/07/95 15:13:25
ivan@78 77 %Current Version: mdwt.m 2.4
ivan@78 78 %File Creation Date: Wed Oct 19 10:51:58 1994
ivan@78 79 %Author: Markus Lang <lang@jazz.rice.edu>
ivan@78 80 %
ivan@78 81 %Copyright (c) 2000 RICE UNIVERSITY. All rights reserved.
ivan@78 82 %Created by Markus Lang, Department of ECE, Rice University.
ivan@78 83 %
ivan@78 84 %This software is distributed and licensed to you on a non-exclusive
ivan@78 85 %basis, free-of-charge. Redistribution and use in source and binary forms,
ivan@78 86 %with or without modification, are permitted provided that the following
ivan@78 87 %conditions are met:
ivan@78 88 %
ivan@78 89 %1. Redistribution of source code must retain the above copyright notice,
ivan@78 90 % this list of conditions and the following disclaimer.
ivan@78 91 %2. Redistribution in binary form must reproduce the above copyright notice,
ivan@78 92 % this list of conditions and the following disclaimer in the
ivan@78 93 % documentation and/or other materials provided with the distribution.
ivan@78 94 %3. All advertising materials mentioning features or use of this software
ivan@78 95 % must display the following acknowledgment: This product includes
ivan@78 96 % software developed by Rice University, Houston, Texas and its contributors.
ivan@78 97 %4. Neither the name of the University nor the names of its contributors
ivan@78 98 % may be used to endorse or promote products derived from this software
ivan@78 99 % without specific prior written permission.
ivan@78 100 %
ivan@78 101 %THIS SOFTWARE IS PROVIDED BY WILLIAM MARSH RICE UNIVERSITY, HOUSTON, TEXAS,
ivan@78 102 %AND CONTRIBUTORS AS IS AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
ivan@78 103 %BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
ivan@78 104 %FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RICE UNIVERSITY
ivan@78 105 %OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
ivan@78 106 %EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
ivan@78 107 %PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
ivan@78 108 %OR BUSINESS INTERRUPTIONS) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
ivan@78 109 %WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
ivan@78 110 %OTHERWISE), PRODUCT LIABILITY, OR OTHERWISE ARISING IN ANY WAY OUT OF THE
ivan@78 111 %USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
ivan@78 112 %
ivan@78 113 %For information on commercial licenses, contact Rice University's Office of
ivan@78 114 %Technology Transfer at techtran@rice.edu or (713) 348-6173
ivan@78 115 %
ivan@78 116 %Change History:
ivan@78 117 %
ivan@78 118 %Modification #1
ivan@78 119 %Mon Aug 7 11:42:11 CDT 1995
ivan@78 120 %Rebecca Hindman <hindman@ece.rice.edu>
ivan@78 121 %Added L to function line so that it can be displayed as an output
ivan@78 122 %
ivan@78 123 %Change History:
ivan@78 124 %
ivan@78 125 %Modification #1
ivan@78 126 %Thu Mar 2 13:07:11 CDT 2000
ivan@78 127 %Ramesh Neelamani<neelsh@ece.rice.edu>
ivan@78 128 %Revamped the help file
ivan@78 129 %
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