function y = perform_wavelet_transform(x, Jmin, dir, options)
% perform_wavelet_transform - wrapper to several wavelet transform.
%
% y = perform_wavelet_transform(x, Jmin, dir, options);
%
% For the orthogonal transform, this function makes use of wavelab.
% For the translation invariant, it tries to uses a lifted transform (for
% 5-3 and 7-9 transform), otherwise it tries to use the Rice Wavelet
% Toolbox (periodic boundary conditions).
%
% 'x' is either a 1D or a 2D array.
% 'Jmin' is the minimum scale (i.e. the coarse channel is of size 2^Jmin
% in 1D).
% 'dir' is +1 for fwd transform and -1 for bwd.
% 'options.wavelet_vm' is the number of Vanishing moment (both for primal and dual).
% 'options.wavelet_type' can be
% 'daubechies', 'symmlet', 'battle', 'biorthogonal'.
% Set options.ti=1 for translation invariant transform (better for denoising).
%
% Typical use :
% M = <load your image here>;
% Jmin = 4;
% options.wavelet_type = 'biorthogonal_swapped';
% options.wavelet_vm = 4;
% MW = perform_wavelet_transform(M, Jmin, +1, options);
% Mt = <perform some modification on MW>
% M = perform_wavelet_transform(Mt, Jmin, -1, options);
%
% 'y' is an array of the same size as 'x'. This means that for the 2D
% we are stuck to the wavelab coding style, i.e. the result
% of each transform is an array organized using Mallat's ordering
% (whereas Matlab official toolbox use a 1D ordering for the 2D transform).
%
% Here the transform automaticaly select symmetric boundary condition
% if you use a symmetric filter. If your filter is not symmetric
% (e.g. Dauechies filters) then as the output must have same length
% as the input, the boundary condition are automatically set to periodic.
%
% For options.ti=0, y has the same size as x.
% For options.ti=1, y is a cell array with y{i} having same size as x.
%
% Copyright (c) 2008 Gabriel Peyre
%
% You do not need Wavelab to use this function (the Wavelab .m file are
% included in this script). However, for faster execution time, you
% should install the mex file within the Wavelab distribution.
% http://www-stat.stanford.edu/~wavelab/
if nargin<3
dir = 1;
end
if nargin<2
Jmin = 3;
end
options.null = 0;
wavelet_type = getoptions(options, 'wavelet_type', 'biorthogonal');
VM = getoptions(options, 'wavelet_vm', 4);
ti = getoptions(options, 'ti', 0);
use_mex = getoptions(options, 'use_mex', 1);
if iscell(x)
ndim = nb_dims(x{1});
else
ndim = nb_dims(x);
end
% for color images
if ndim==3 && size(x,3)<=4
y = x;
for i=1:size(x,3)
y(:,:,i) = perform_wavelet_transform(x(:,:,i), Jmin, dir, options);
end
return;
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% WAVELAB
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% generate filters
dqmf = [];
switch lower(wavelet_type)
case 'daubechies'
qmf = MakeONFilter('Daubechies',VM*2); % in Wavelab, 2nd argument is VM*2 for Daubechies... no comment ...
case 'haar'
qmf = MakeONFilter('Haar'); % in Wavelab, 2nd argument is VM*2 for Daubechies... no comment ...
case 'symmlet'
qmf = MakeONFilter('Symmlet',VM);
case 'battle'
qmf = MakeONFilter('Battle',VM-1);
dqmf = qmf; % we need dual filter
case 'biorthogonal'
[qmf,dqmf] = MakeBSFilter( 'CDF', [VM,VM] );
case 'biorthogonal_swapped'
[dqmf,qmf] = MakeBSFilter( 'CDF', [VM,VM] );
otherwise
error('Unknown transform.');
end
%% translation invariant transform
if ti==1
%%%% Mex LIW implementation %%%%
if use_mex && exist('cwpt2_interface') && ndim==2 && ...
( strcmp(wavelet_type, 'biorthogonal') || strcmp(wavelet_type, 'biorthogonal_swapped') )
y = interface_liw(x, Jmin, options);
return;
end
%%%% Mex RWT implementation %%%%
if use_mex && exist('mirdwt') && exist('mrdwt')
y = interface_rwt(x, Jmin, qmf, dqmf);
return;
end
%%%% Lifting implementation %%%%
if strcmp(wavelet_type, 'biorthogonal') || strcmp(wavelet_type, 'biorthogonal_swapped')
y = interface_lifting(x, Jmin, VM);
return;
end
%%%% Wavelab implementation %%%%%
if isempty(dqmf)
y = interface_wavelab_ti(x, Jmin, qmf);
return;
end
error('This TI transform is not implemented.');
return;
end
% perform transform
if ~exist('dqmf') || isempty(dqmf)
%%% ORTHOGONAL %%%
if ndim==1
if dir==1
y = FWT_PO(x,Jmin,qmf);
else
y = IWT_PO(x,Jmin,qmf);
end
elseif ndim==2
if dir==1
y = FWT2_PO(x,Jmin,qmf);
else
y = IWT2_PO(x,Jmin,qmf);
end
end
else
%%% BI-ORTHOGONAL %%%
if ndim==1
if dir==1
y = FWT_SBS(x,Jmin,qmf,dqmf);
else
y = IWT_SBS(x,Jmin,qmf,dqmf);
end
elseif ndim==2
if dir==1
y = FWT2_SBS(x,Jmin,qmf,dqmf);
else
y = IWT2_SBS(x,Jmin,qmf,dqmf);
end
end
end
%% Transform matrix into cell array
function y = transfert_ti(x)
if iscell(x)
dir = -1; ndim = nb_dims(x{1});
else
dir = 1; ndim = nb_dims(x);
end
if dir==-1
% turn into cell matrix
if ndim==1
% 1D
y = cell2mat(x);
else
% 2D
y = zeros(size(x{1},1),size(x{1},2),length(x));
for i=1:size(y,3)
y(:,:,i) = x{i};
end
end
else
% turn into cell array
if size(x,3)==1
% 1D
y = mat2cell(x, size(x,1), ones(size(x,2),1));
else
% 2D
y = {};
for i=1:size(x,3)
y{end+1} = x(:,:,i);
end
end
end
%% wavelab TI interface
function y = interface_wavelab_ti(x, Jmin, qmf)
if iscell(x)
dir = -1; ndim = nb_dims(x{1});
else
dir = 1; ndim = nb_dims(x);
end
if ndim==1
if dir==1
y = TI2Stat( FWT_TI(x,Jmin,qmf) );
% transform into cell array
y = transfert_ti(y);
else
x = transfert_ti(x);
y = IWT_TI( Stat2TI(x),qmf);
y = y(:);
end
elseif ndim==2
if dir==1
y = FWT2_TI(x,Jmin,qmf);
n = size(x,1);
y = reshape( y, [n size(y,1)/n n] );
y = permute(y, [1 3 2]);
% transform into cell array
y = transfert_ti(y);
else
x = transfert_ti(x);
x = permute(x, [1 3 2]);
x = reshape( x, [size(x,1)*size(x,2) size(x,3)] );
y = IWT2_TI(x,Jmin,qmf);
end
end
%% lifting interface
function y = interface_lifting(x, Jmin, wavelet_vm)
if wavelet_vm==2
options.filter = 'linear';
else
options.filter = '9-7';
end
options.ti = 1;
dir = 1;
if iscell(x)
dir = -1;
end
if dir<0
x = { x{end} x{end-1:-1:1} };
x = transfert_ti(x);
if size(x,3)==1
% 1D
x = reshape(x, [size(x,1) 1 size(x,2)]);
end
end
y = perform_lifting_transform(x, Jmin, dir, options);
if dir>0
y = transfert_ti(squeeze(y));
% reverse frequencies
y = { y{end:-1:2} y{1} };
end
%% RWT interface
function y = interface_rwt(x, Jmin, qmf, dqmf)
if isempty(dqmf)
dqmf = qmf;
end
if iscell(x)
ndim = nb_dims(x{1});
else
ndim = nb_dims(x);
end
%%% USING RWT %%%
if ~iscell(x)
n = length(x);
Jmax = log2(n)-1;
%%% FORWARD TRANSFORM %%%
L = Jmax-Jmin+1;
[yl,yh,L] = mrdwt(x, qmf, L);
% turn into cell array
if ndim==1
y = cat(2,yl,yh);
y = transfert_ti(y);
else
%% 2D %%
for j=Jmax:-1:Jmin
for q=1:3
s = 3*(Jmax-j)+q-1;
M = yh(:,s*n+1:(s+1)*n);
y{ 3*(j-Jmin)+q } = M;
end
end
y{ 3*(Jmax-Jmin)+4 } = yl;
end
% reverse the order of the frequencies
y = { y{end-1:-1:1} y{end} };
else
n = length(x{1});
Jmax = log2(n)-1;
L = Jmax-Jmin+1;
% reverse the order of the frequencies
x = { x{end-1:-1:1} x{end} };
% turn into array
if ndim==1
%% 1D %%
x = transfert_ti(x);
yl = x(:,1);
yh = x(:,2:end);
else
%% 2D %%
if L ~= (length(x)-1)/3
warning('Jmin is not correct.');
L = (length(x)-1)/3;
end
yl = x{ 3*(Jmax-Jmin)+4 };
yh = zeros( n,3*L*n );
for j=Jmax:-1:Jmin
for q=1:3
s = 3*(Jmax-j)+q-1;
yh(:,s*n+1:(s+1)*n) = x{ 3*(j-Jmin)+q };
end
end
end
%%% BACKWARD TRANSFORM %%%
[y,L] = mirdwt(yl,yh,dqmf,L);
end
%% LetIt wave interface
function y = interface_liw(x, Jmin, options)
% either 'quad' or 'tri'
decomp_type = getoptions(options, 'decomp_type', 'quad');
wavelet_types = '7-9';
% wavelet_types = 'spline';
if ~iscell(x)
dirs = 'forward';
J = log2(size(x,1)) - Jmin;
M = x;
else
dirs = 'inverse';
if strcmp(decomp_type, 'tri')
x = { x{1:end-3}, x{end}, x{end-2:end-1} };
else
x = { x{1:end-4}, x{end}, x{end-3:end-1} };
end
J = 0;
M = zeros(size(x{1},1), size(x{1},2), J);
for i=1:length(x)
M(:,:,i) = x{i};
end
end
y = cwpt2_interface(M, dirs, wavelet_types, decomp_type, J);
if ~iscell(x)
M = y; y = {};
for i=1:size(M,3)
y{i} = M(:,:,i);
end
% put low frequency at the end
if strcmp(decomp_type, 'tri')
y = { y{1:end-3}, y{end-1:end}, y{end-2} };
else
y = { y{1:end-4}, y{end-2:end}, y{end-3} };
end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% WAVELAB DISTRIBUTION -- http://www-stat.stanford.edu/~wavelab/
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% WAVELAB DISTRIBUTION -- http://www-stat.stanford.edu/~wavelab/
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function f = MakeONFilter(Type,Par)
% MakeONFilter -- Generate Orthonormal QMF Filter for Wavelet Transform
% Usage
% qmf = MakeONFilter(Type,Par)
% Inputs
% Type string, 'Haar', 'Beylkin', 'Coiflet', 'Daubechies',
% 'Symmlet', 'Vaidyanathan','Battle'
% Par integer, it is a parameter related to the support and vanishing
% moments of the wavelets, explained below for each wavelet.
%
% Outputs
% qmf quadrature mirror filter
%
% Description
% The Haar filter (which could be considered a Daubechies-2) was the
% first wavelet, though not called as such, and is discontinuous.
%
% The Beylkin filter places roots for the frequency response function
% close to the Nyquist frequency on the real axis.
%
% The Coiflet filters are designed to give both the mother and father
% wavelets 2*Par vanishing moments; here Par may be one of 1,2,3,4 or 5.
%
% The Daubechies filters are minimal phase filters that generate wavelets
% which have a minimal support for a given number of vanishing moments.
% They are indexed by their length, Par, which may be one of
% 4,6,8,10,12,14,16,18 or 20. The number of vanishing moments is par/2.
%
% Symmlets are also wavelets within a minimum size support for a given
% number of vanishing moments, but they are as symmetrical as possible,
% as opposed to the Daubechies filters which are highly asymmetrical.
% They are indexed by Par, which specifies the number of vanishing
% moments and is equal to half the size of the support. It ranges
% from 4 to 10.
%
% The Vaidyanathan filter gives an exact reconstruction, but does not
% satisfy any moment condition. The filter has been optimized for
% speech coding.
%
% The Battle-Lemarie filter generate spline orthogonal wavelet basis.
% The parameter Par gives the degree of the spline. The number of
% vanishing moments is Par+1.
%
% See Also
% FWT_PO, IWT_PO, FWT2_PO, IWT2_PO, WPAnalysis
%
% References
% The books by Daubechies and Wickerhauser.
%
if strcmp(Type,'Haar'),
f = [1 1] ./ sqrt(2);
end
if strcmp(Type,'Beylkin'),
f = [ .099305765374 .424215360813 .699825214057 ...
.449718251149 -.110927598348 -.264497231446 ...
.026900308804 .155538731877 -.017520746267 ...
-.088543630623 .019679866044 .042916387274 ...
-.017460408696 -.014365807969 .010040411845 ...
.001484234782 -.002736031626 .000640485329 ];
end
if strcmp(Type,'Coiflet'),
if Par==1,
f = [ .038580777748 -.126969125396 -.077161555496 ...
.607491641386 .745687558934 .226584265197 ];
end
if Par==2,
f = [ .016387336463 -.041464936782 -.067372554722 ...
.386110066823 .812723635450 .417005184424 ...
-.076488599078 -.059434418646 .023680171947 ...
.005611434819 -.001823208871 -.000720549445 ];
end
if Par==3,
f = [ -.003793512864 .007782596426 .023452696142 ...
-.065771911281 -.061123390003 .405176902410 ...
.793777222626 .428483476378 -.071799821619 ...
-.082301927106 .034555027573 .015880544864 ...
-.009007976137 -.002574517688 .001117518771 ...
.000466216960 -.000070983303 -.000034599773 ];
end
if Par==4,
f = [ .000892313668 -.001629492013 -.007346166328 ...
.016068943964 .026682300156 -.081266699680 ...
-.056077313316 .415308407030 .782238930920 ...
.434386056491 -.066627474263 -.096220442034 ...
.039334427123 .025082261845 -.015211731527 ...
-.005658286686 .003751436157 .001266561929 ...
-.000589020757 -.000259974552 .000062339034 ...
.000031229876 -.000003259680 -.000001784985 ];
end
if Par==5,
f = [ -.000212080863 .000358589677 .002178236305 ...
-.004159358782 -.010131117538 .023408156762 ...
.028168029062 -.091920010549 -.052043163216 ...
.421566206729 .774289603740 .437991626228 ...
-.062035963906 -.105574208706 .041289208741 ...
.032683574283 -.019761779012 -.009164231153 ...
.006764185419 .002433373209 -.001662863769 ...
-.000638131296 .000302259520 .000140541149 ...
-.000041340484 -.000021315014 .000003734597 ...
.000002063806 -.000000167408 -.000000095158 ];
end
end
if strcmp(Type,'Daubechies'),
if Par==4,
f = [ .482962913145 .836516303738 ...
.224143868042 -.129409522551 ];
end
if Par==6,
f = [ .332670552950 .806891509311 ...
.459877502118 -.135011020010 ...
-.085441273882 .035226291882 ];
end
if Par==8,
f = [ .230377813309 .714846570553 ...
.630880767930 -.027983769417 ...
-.187034811719 .030841381836 ...
.032883011667 -.010597401785 ];
end
if Par==10,
f = [ .160102397974 .603829269797 .724308528438 ...
.138428145901 -.242294887066 -.032244869585 ...
.077571493840 -.006241490213 -.012580751999 ...
.003335725285 ];
end
if Par==12,
f = [ .111540743350 .494623890398 .751133908021 ...
.315250351709 -.226264693965 -.129766867567 ...
.097501605587 .027522865530 -.031582039317 ...
.000553842201 .004777257511 -.001077301085 ];
end
if Par==14,
f = [ .077852054085 .396539319482 .729132090846 ...
.469782287405 -.143906003929 -.224036184994 ...
.071309219267 .080612609151 -.038029936935 ...
-.016574541631 .012550998556 .000429577973 ...
-.001801640704 .000353713800 ];
end
if Par==16,
f = [ .054415842243 .312871590914 .675630736297 ...
.585354683654 -.015829105256 -.284015542962 ...
.000472484574 .128747426620 -.017369301002 ...
-.044088253931 .013981027917 .008746094047 ...
-.004870352993 -.000391740373 .000675449406 ...
-.000117476784 ];
end
if Par==18,
f = [ .038077947364 .243834674613 .604823123690 ...
.657288078051 .133197385825 -.293273783279 ...
-.096840783223 .148540749338 .030725681479 ...
-.067632829061 .000250947115 .022361662124 ...
-.004723204758 -.004281503682 .001847646883 ...
.000230385764 -.000251963189 .000039347320 ];
end
if Par==20,
f = [ .026670057901 .188176800078 .527201188932 ...
.688459039454 .281172343661 -.249846424327 ...
-.195946274377 .127369340336 .093057364604 ...
-.071394147166 -.029457536822 .033212674059 ...
.003606553567 -.010733175483 .001395351747 ...
.001992405295 -.000685856695 -.000116466855 ...
.000093588670 -.000013264203 ];
end
end
if strcmp(Type,'Symmlet'),
if Par==4,
f = [ -.107148901418 -.041910965125 .703739068656 ...
1.136658243408 .421234534204 -.140317624179 ...
-.017824701442 .045570345896 ];
end
if Par==5,
f = [ .038654795955 .041746864422 -.055344186117 ...
.281990696854 1.023052966894 .896581648380 ...
.023478923136 -.247951362613 -.029842499869 ...
.027632152958 ];
end
if Par==6,
f = [ .021784700327 .004936612372 -.166863215412 ...
-.068323121587 .694457972958 1.113892783926 ...
.477904371333 -.102724969862 -.029783751299 ...
.063250562660 .002499922093 -.011031867509 ];
end
if Par==7,
f = [ .003792658534 -.001481225915 -.017870431651 ...
.043155452582 .096014767936 -.070078291222 ...
.024665659489 .758162601964 1.085782709814 ...
.408183939725 -.198056706807 -.152463871896 ...
.005671342686 .014521394762 ];
end
if Par==8,
f = [ .002672793393 -.000428394300 -.021145686528 ...
.005386388754 .069490465911 -.038493521263 ...
-.073462508761 .515398670374 1.099106630537 ...
.680745347190 -.086653615406 -.202648655286 ...
.010758611751 .044823623042 -.000766690896 ...
-.004783458512 ];
end
if Par==9,
f = [ .001512487309 -.000669141509 -.014515578553 ...
.012528896242 .087791251554 -.025786445930 ...
-.270893783503 .049882830959 .873048407349 ...
1.015259790832 .337658923602 -.077172161097 ...
.000825140929 .042744433602 -.016303351226 ...
-.018769396836 .000876502539 .001981193736 ];
end
if Par==10,
f = [ .001089170447 .000135245020 -.012220642630 ...
-.002072363923 .064950924579 .016418869426 ...
-.225558972234 -.100240215031 .667071338154 ...
1.088251530500 .542813011213 -.050256540092 ...
-.045240772218 .070703567550 .008152816799 ...
-.028786231926 -.001137535314 .006495728375 ...
.000080661204 -.000649589896 ];
end
end
if strcmp(Type,'Vaidyanathan'),
f = [ -.000062906118 .000343631905 -.000453956620 ...
-.000944897136 .002843834547 .000708137504 ...
-.008839103409 .003153847056 .019687215010 ...
-.014853448005 -.035470398607 .038742619293 ...
.055892523691 -.077709750902 -.083928884366 ...
.131971661417 .135084227129 -.194450471766 ...
-.263494802488 .201612161775 .635601059872 ...
.572797793211 .250184129505 .045799334111 ];
end
if strcmp(Type,'Battle'),
if Par == 1,
g = [0.578163 0.280931 -0.0488618 -0.0367309 ...
0.012003 0.00706442 -0.00274588 -0.00155701 ...
0.000652922 0.000361781 -0.000158601 -0.0000867523
];
end
if Par == 3,
g = [0.541736 0.30683 -0.035498 -0.0778079 ...
0.0226846 0.0297468 -0.0121455 -0.0127154 ...
0.00614143 0.00579932 -0.00307863 -0.00274529 ...
0.00154624 0.00133086 -0.000780468 -0.00065562 ...
0.000395946 0.000326749 -0.000201818 -0.000164264 ...
0.000103307
];
end
if Par == 5,
g = [0.528374 0.312869 -0.0261771 -0.0914068 ...
0.0208414 0.0433544 -0.0148537 -0.0229951 ...
0.00990635 0.0128754 -0.00639886 -0.00746848 ...
0.00407882 0.00444002 -0.00258816 -0.00268646 ...
0.00164132 0.00164659 -0.00104207 -0.00101912 ...
0.000662836 0.000635563 -0.000422485 -0.000398759 ...
0.000269842 0.000251419 -0.000172685 -0.000159168 ...
0.000110709 0.000101113
];
end
l = length(g);
f = zeros(1,2*l-1);
f(l:2*l-1) = g;
f(1:l-1) = reverse(g(2:l));
end
f = f ./ norm(f);
%
% Copyright (c) 1993-5. Jonathan Buckheit and David Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function wcoef = FWT_PO(x,L,qmf)
% FWT_PO -- Forward Wavelet Transform (periodized, orthogonal)
% Usage
% wc = FWT_PO(x,L,qmf)
% Inputs
% x 1-d signal; length(x) = 2^J
% L Coarsest Level of V_0; L << J
% qmf quadrature mirror filter (orthonormal)
% Outputs
% wc 1-d wavelet transform of x.
%
% Description
% 1. qmf filter may be obtained from MakeONFilter
% 2. usually, length(qmf) < 2^(L+1)
% 3. To reconstruct use IWT_PO
%
% See Also
% IWT_PO, MakeONFilter
%
[n,J] = dyadlength(x) ;
wcoef = zeros(1,n) ;
beta = ShapeAsRow(x); %take samples at finest scale as beta-coeffts
for j=J-1:-1:L
alfa = DownDyadHi(beta,qmf);
wcoef(dyad(j)) = alfa;
beta = DownDyadLo(beta,qmf) ;
end
wcoef(1:(2^L)) = beta;
wcoef = ShapeLike(wcoef,x);
%
% Copyright (c) 1993. Iain M. Johnstone
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function [n,J] = dyadlength(x)
% dyadlength -- Find length and dyadic length of array
% Usage
% [n,J] = dyadlength(x)
% Inputs
% x array of length n = 2^J (hopefully)
% Outputs
% n length(x)
% J least power of two greater than n
%
% Side Effects
% A warning is issued if n is not a power of 2.
%
% See Also
% quadlength, dyad, dyad2ix
%
n = length(x) ;
J = ceil(log(n)/log(2));
if 2^J ~= n ,
disp('Warning in dyadlength: n != 2^J')
end
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function row = ShapeAsRow(sig)
% ShapeAsRow -- Make signal a row vector
% Usage
% row = ShapeAsRow(sig)
% Inputs
% sig a row or column vector
% Outputs
% row a row vector
%
% See Also
% ShapeLike
%
row = sig(:)';
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function d = DownDyadHi(x,qmf)
% DownDyadHi -- Hi-Pass Downsampling operator (periodized)
% Usage
% d = DownDyadHi(x,f)
% Inputs
% x 1-d signal at fine scale
% f filter
% Outputs
% y 1-d signal at coarse scale
%
% See Also
% DownDyadLo, UpDyadHi, UpDyadLo, FWT_PO, iconv
%
d = iconv( MirrorFilt(qmf),lshift(x));
n = length(d);
d = d(1:2:(n-1));
%
% Copyright (c) 1993. Iain M. Johnstone
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = MirrorFilt(x)
% MirrorFilt -- Apply (-1)^t modulation
% Usage
% h = MirrorFilt(l)
% Inputs
% l 1-d signal
% Outputs
% h 1-d signal with DC frequency content shifted
% to Nyquist frequency
%
% Description
% h(t) = (-1)^(t-1) * x(t), 1 <= t <= length(x)
%
% See Also
% DyadDownHi
%
y = -( (-1).^(1:length(x)) ).*x;
%
% Copyright (c) 1993. Iain M. Johnstone
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = lshift(x)
% lshift -- Circular left shift of 1-d signal
% Usage
% l = lshift(x)
% Inputs
% x 1-d signal
% Outputs
% l 1-d signal
% l(i) = x(i+1) except l(n) = x(1)
%
y = [ x( 2:length(x) ) x(1) ];
%
% Copyright (c) 1993. Iain M. Johnstone
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = iconv(f,x)
% iconv -- Convolution Tool for Two-Scale Transform
% Usage
% y = iconv(f,x)
% Inputs
% f filter
% x 1-d signal
% Outputs
% y filtered result
%
% Description
% Filtering by periodic convolution of x with f
%
% See Also
% aconv, UpDyadHi, UpDyadLo, DownDyadHi, DownDyadLo
%
n = length(x);
p = length(f);
if p <= n,
xpadded = [x((n+1-p):n) x];
else
z = zeros(1,p);
for i=1:p,
imod = 1 + rem(p*n -p + i-1,n);
z(i) = x(imod);
end
xpadded = [z x];
end
ypadded = filter(f,1,xpadded);
y = ypadded((p+1):(n+p));
%
% Copyright (c) 1993. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function i = dyad(j)
% dyad -- Index entire j-th dyad of 1-d wavelet xform
% Usage
% ix = dyad(j);
% Inputs
% j integer
% Outputs
% ix list of all indices of wavelet coeffts at j-th level
%
i = (2^(j)+1):(2^(j+1)) ;
%
% Copyright (c) 1993. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function d = DownDyadLo(x,qmf)
% DownDyadLo -- Lo-Pass Downsampling operator (periodized)
% Usage
% d = DownDyadLo(x,f)
% Inputs
% x 1-d signal at fine scale
% f filter
% Outputs
% y 1-d signal at coarse scale
%
% See Also
% DownDyadHi, UpDyadHi, UpDyadLo, FWT_PO, aconv
%
d = aconv(qmf,x);
n = length(d);
d = d(1:2:(n-1));
%
% Copyright (c) 1993. Iain M. Johnstone
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = aconv(f,x)
% aconv -- Convolution Tool for Two-Scale Transform
% Usage
% y = aconv(f,x)
% Inputs
% f filter
% x 1-d signal
% Outputs
% y filtered result
%
% Description
% Filtering by periodic convolution of x with the
% time-reverse of f.
%
% See Also
% iconv, UpDyadHi, UpDyadLo, DownDyadHi, DownDyadLo
%
n = length(x);
p = length(f);
if p < n,
xpadded = [x x(1:p)];
else
z = zeros(1,p);
for i=1:p,
imod = 1 + rem(i-1,n);
z(i) = x(imod);
end
xpadded = [x z];
end
fflip = reverse(f);
ypadded = filter(fflip,1,xpadded);
y = ypadded(p:(n+p-1));
%
% Copyright (c) 1993. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function vec = ShapeLike(sig,proto)
% ShapeLike -- Make 1-d signal with given shape
% Usage
% vec = ShapeLike(sig,proto)
% Inputs
% sig a row or column vector
% proto a prototype shape (row or column vector)
% Outputs
% vec a vector with contents taken from sig
% and same shape as proto
%
% See Also
% ShapeAsRow
%
sp = size(proto);
ss = size(sig);
if( sp(1)>1 & sp(2)>1 )
disp('Weird proto argument to ShapeLike')
elseif ss(1)>1 & ss(2) > 1,
disp('Weird sig argument to ShapeLike')
else
if(sp(1) > 1),
if ss(1) > 1,
vec = sig;
else
vec = sig(:);
end
else
if ss(2) > 1,
vec = sig;
else
vec = sig(:)';
end
end
end
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function x = IWT_PO(wc,L,qmf)
% IWT_PO -- Inverse Wavelet Transform (periodized, orthogonal)
% Usage
% x = IWT_PO(wc,L,qmf)
% Inputs
% wc 1-d wavelet transform: length(wc) = 2^J.
% L Coarsest scale (2^(-L) = scale of V_0); L << J;
% qmf quadrature mirror filter
% Outputs
% x 1-d signal reconstructed from wc
%
% Description
% Suppose wc = FWT_PO(x,L,qmf) where qmf is an orthonormal quad. mirror
% filter, e.g. one made by MakeONFilter. Then x can be reconstructed by
% x = IWT_PO(wc,L,qmf)
%
% See Also
% FWT_PO, MakeONFilter
%
wcoef = ShapeAsRow(wc);
x = wcoef(1:2^L);
[n,J] = dyadlength(wcoef);
for j=L:J-1
x = UpDyadLo(x,qmf) + UpDyadHi(wcoef(dyad(j)),qmf) ;
end
x = ShapeLike(x,wc);
%
% Copyright (c) 1993. Iain M. Johnstone
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = UpDyadLo(x,qmf)
% UpDyadLo -- Lo-Pass Upsampling operator; periodized
% Usage
% u = UpDyadLo(d,f)
% Inputs
% d 1-d signal at coarser scale
% f filter
% Outputs
% u 1-d signal at finer scale
%
% See Also
% DownDyadLo, DownDyadHi, UpDyadHi, IWT_PO, iconv
%
y = iconv(qmf, UpSample(x) );
%
% Copyright (c) 1993. Iain M. Johnstone
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = UpSample(x,s)
% UpSample -- Upsampling operator
% Usage
% u = UpSample(d[,s])
% Inputs
% d 1-d signal, of length n
% s upsampling scale, default = 2
% Outputs
% u 1-d signal, of length s*n with zeros
% interpolating alternate samples
% u(s*i-1) = d(i), i=1,...,n
%
if nargin == 1, s = 2; end
n = length(x)*s;
y = zeros(1,n);
y(1:s:(n-s+1) )=x;
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = UpDyadHi(x,qmf)
% UpDyadHi -- Hi-Pass Upsampling operator; periodized
% Usage
% u = UpDyadHi(d,f)
% Inputs
% d 1-d signal at coarser scale
% f filter
% Outputs
% u 1-d signal at finer scale
%
% See Also
% DownDyadLo, DownDyadHi, UpDyadLo, IWT_PO, aconv
%
y = aconv( MirrorFilt(qmf), rshift( UpSample(x) ) );
%
% Copyright (c) 1993. Iain M. Johnstone
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = rshift(x)
% rshift -- Circular right shift of 1-d signal
% Usage
% r = rshift(x)
% Inputs
% x 1-d signal
% Outputs
% r 1-d signal
% r(i) = x(i-1) except r(1) = x(n)
%
n = length(x);
y = [ x(n) x( 1: (n-1) )];
%
% Copyright (c) 1993. Iain M. Johnstone
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function [qmf,dqmf] = MakeBSFilter(Type,Par)
% MakeBSFilter -- Generate Biorthonormal QMF Filter Pairs
% Usage
% [qmf,dqmf] = MakeBSFilter(Type,Par)
% Inputs
% Type string, one of:
% 'Triangle'
% 'Interpolating' 'Deslauriers' (the two are same)
% 'Average-Interpolating'
% 'CDF' (spline biorthogonal filters in Daubechies's book)
% 'Villasenor' (Villasenor's 5 best biorthogonal filters)
% Par integer list, e.g. if Type ='Deslauriers', Par=3 specifies
% Deslauriers-Dubuc filter, polynomial degree 3
% Outputs
% qmf quadrature mirror filter (odd length, symmetric)
% dqmf dual quadrature mirror filter (odd length, symmetric)
%
% See Also
% FWT_PBS, IWT_PBS, FWT2_PBS, IWT2_PBS
%
% References
% I. Daubechies, "Ten Lectures on Wavelets."
%
% G. Deslauriers and S. Dubuc, "Symmetric Iterative Interpolating Processes."
%
% D. Donoho, "Smooth Wavelet Decompositions with Blocky Coefficient Kernels."
%
% J. Villasenor, B. Belzer and J. Liao, "Wavelet Filter Evaluation for
% Image Compression."
%
if nargin < 2,
Par = 0;
end
sqr2 = sqrt(2);
if strcmp(Type,'Triangle'),
qmf = [0 1 0];
dqmf = [.5 1 .5];
elseif strcmp(Type,'Interpolating') | strcmp(Type,'Deslauriers'),
qmf = [0 1 0];
dqmf = MakeDDFilter(Par)';
dqmf = dqmf(1:(length(dqmf)-1));
elseif strcmp(Type,'Average-Interpolating'),
qmf = [0 .5 .5] ;
dqmf = [0 ; MakeAIFilter(Par)]';
elseif strcmp(Type,'CDF'),
if Par(1)==1,
dqmf = [0 .5 .5] .* sqr2;
if Par(2) == 1,
qmf = [0 .5 .5] .* sqr2;
elseif Par(2) == 3,
qmf = [0 -1 1 8 8 1 -1] .* sqr2 / 16;
elseif Par(2) == 5,
qmf = [0 3 -3 -22 22 128 128 22 -22 -3 3].*sqr2/256;
end
elseif Par(1)==2,
dqmf = [.25 .5 .25] .* sqr2;
if Par(2)==2,
qmf = [-.125 .25 .75 .25 -.125] .* sqr2;
elseif Par(2)==4,
qmf = [3 -6 -16 38 90 38 -16 -6 3] .* (sqr2/128);
elseif Par(2)==6,
qmf = [-5 10 34 -78 -123 324 700 324 -123 -78 34 10 -5 ] .* (sqr2/1024);
elseif Par(2)==8,
qmf = [35 -70 -300 670 1228 -3126 -3796 10718 22050 ...
10718 -3796 -3126 1228 670 -300 -70 35 ] .* (sqr2/32768);
end
elseif Par(1)==3,
dqmf = [0 .125 .375 .375 .125] .* sqr2;
if Par(2) == 1,
qmf = [0 -.25 .75 .75 -.25] .* sqr2;
elseif Par(2) == 3,
qmf = [0 3 -9 -7 45 45 -7 -9 3] .* sqr2/64;
elseif Par(2) == 5,
qmf = [0 -5 15 19 -97 -26 350 350 -26 -97 19 15 -5] .* sqr2/512;
elseif Par(2) == 7,
qmf = [0 35 -105 -195 865 363 -3489 -307 11025 11025 -307 -3489 363 865 -195 -105 35] .* sqr2/16384;
elseif Par(2) == 9,
qmf = [0 -63 189 469 -1911 -1308 9188 1140 -29676 190 87318 87318 190 -29676 ...
1140 9188 -1308 -1911 469 189 -63] .* sqr2/131072;
end
elseif Par(1)==4,
dqmf = [.026748757411 -.016864118443 -.078223266529 .266864118443 .602949018236 ...
.266864118443 -.078223266529 -.016864118443 .026748757411] .*sqr2;
if Par(2) == 4,
qmf = [0 -.045635881557 -.028771763114 .295635881557 .557543526229 ...
.295635881557 -.028771763114 -.045635881557 0] .*sqr2;
end
end
elseif strcmp(Type,'Villasenor'),
if Par == 1,
% The "7-9 filters"
qmf = [.037828455506995 -.023849465019380 -.11062440441842 .37740285561265];
qmf = [qmf .85269867900940 reverse(qmf)];
dqmf = [-.064538882628938 -.040689417609558 .41809227322221];
dqmf = [dqmf .78848561640566 reverse(dqmf)];
elseif Par == 2,
qmf = [-.008473 .003759 .047282 -.033475 -.068867 .383269 .767245 .383269 -.068867...
-.033475 .047282 .003759 -.008473];
dqmf = [0.014182 0.006292 -0.108737 -0.069163 0.448109 .832848 .448109 -.069163 -.108737 .006292 .014182];
elseif Par == 3,
qmf = [0 -.129078 .047699 .788486 .788486 .047699 -.129078];
dqmf = [0 .018914 .006989 -.067237 .133389 .615051 .615051 .133389 -.067237 .006989 .018914];
elseif Par == 4,
qmf = [-1 2 6 2 -1] / (4*sqr2);
dqmf = [1 2 1] / (2*sqr2);
elseif Par == 5,
qmf = [0 1 1]/sqr2;
dqmf = [0 -1 1 8 8 1 -1]/(8*sqr2);
end
end
%
% Copyright (c) 1995. Jonathan Buckheit, Shaobing Chen and David Donoho
%
% Modified by Maureen Clerc and Jerome Kalifa, 1997
% clerc@cmapx.polytechnique.fr, kalifa@cmapx.polytechnique.fr
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function wcoef = FWT_SBS(x,L,qmf,dqmf)
% FWT_SBS -- Forward Wavelet Transform (symmetric extension, biorthogonal, symmetric)
% Usage
% wc = FWT_SBS(x,L,qmf,dqmf)
% Inputs
% x 1-d signal; arbitrary length
% L Coarsest Level of V_0; L << J
% qmf quadrature mirror filter (symmetric)
% dqmf quadrature mirror filter (symmetric, dual of qmf)
% Outputs
% wc 1-d wavelet transform of x.
%
% Description
% 1. qmf filter may be obtained from MakePBSFilter
% 2. usually, length(qmf) < 2^(L+1)
% 3. To reconstruct use IWT_SBS
%
% See Also
% IWT_SBS, MakePBSFilter
%
% References
% Based on the algorithm developed by Christopher Brislawn.
% See "Classification of Symmetric Wavelet Transforms"
%
[n,J] = dyadlength(x);
wcoef = zeros(1,n);
beta = ShapeAsRow(x); % take samples at finest scale as beta-coeffts
dp = dyadpartition(n);
for j=J-1:-1:L,
[beta, alfa] = DownDyad_SBS(beta,qmf,dqmf);
dyadj = (dp(j+1)+1):dp(j+2);
wcoef(dyadj) = alfa;
end
wcoef(1:length(beta)) = beta;
wcoef = ShapeLike(wcoef,x);
%
% Copyright (c) 1996. Thomas P.Y. Yu
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function dp = dyadpartition(n)
% dyadpartition -- determine dyadic partition in wavelet transform of
% nondyadic signals
J = ceil(log2(n));
m = n;
for j=J-1:-1:0;
if rem(m,2)==0,
dps(j+1) = m/2;
m = m/2;
else
dps(j+1) = (m-1)/2;
m = (m+1)/2;
end
end
dp = cumsum([1 dps]);
%
% Copyright (c) 1996. Thomas P.Y. Yu
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function [beta, alpha] = DownDyad_SBS(x,qmf,dqmf)
% DownDyad_SBS -- Symmetric Downsampling operator
% Usage
% [beta,alpha] = DownDyad_SBS(x,qmf,dqmf)
% Inputs
% x 1-d signal at fine scale
% qmf quadrature mirror filter
% dqmf dual quadrature mirror filter
% Outputs
% beta coarse coefficients
% alpha fine coefficients
% See Also
% FWT_SBS
%
% oddf = (rem(length(qmf),2)==1);
oddf = ~(qmf(1)==0 & qmf(length(qmf))~=0);
oddx = (rem(length(x),2)==1);
% symmetric extension of x
if oddf,
ex = extend(x,1,1);
else
ex = extend(x,2,2);
end
% convolution
ebeta = DownDyadLo_PBS(ex,qmf);
ealpha = DownDyadHi_PBS(ex,dqmf);
% project
if oddx,
beta = ebeta(1:(length(x)+1)/2);
alpha = ealpha(1:(length(x)-1)/2);
else
beta = ebeta(1:length(x)/2);
alpha = ealpha(1:length(x)/2);
end
%
% Copyright (c) 1996. Thomas P.Y. Yu
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = extend(x, par1, par2)
% extend -- perform various kinds of symmetric extension
%
if par1==1 & par2==1,
y = [x x((length(x)-1):-1:2)];
elseif par1==1 & par2==2,
y = [x x((length(x)-1):-1:1)];
elseif par1==2 & par2==1,
y = [x x(length(x):-1:2)];
elseif par1==2 & par2==2,
y = [x reverse(x)];
end
%
% Copyright (c) 1996. Thomas P.Y. Yu
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function d = DownDyadLo_PBS(x,qmf)
% DownDyadLo_PBS -- Lo-Pass Downsampling operator (periodized,symmetric)
% Usage
% d = DownDyadLo_PBS(x,sf)
% Inputs
% x 1-d signal at fine scale
% sf symmetric filter
% Outputs
% y 1-d signal at coarse scale
%
% See Also
% DownDyadHi_PBS, UpDyadHi_PBS, UpDyadLo_PBS, FWT_PBSi, symm_aconv
%
d = symm_aconv(qmf,x);
n = length(d);
d = d(1:2:(n-1));
%
% Copyright (c) 1995. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = symm_aconv(sf,x)
% symm_aconv -- Symmetric Convolution Tool for Two-Scale Transform
% Usage
% y = symm_aconv(sf,x)
% Inputs
% sf symmetric filter
% x 1-d signal
% Outputs
% y filtered result
%
% Description
% Filtering by periodic convolution of x with the
% time-reverse of sf.
%
% See Also
% symm_iconv, UpDyadHi_PBS, UpDyadLo_PBS, DownDyadHi_PBS, DownDyadLo_PBS
%
n = length(x);
p = length(sf);
if p < n,
xpadded = [x x(1:p)];
else
z = zeros(1,p);
for i=1:p,
imod = 1 + rem(i-1,n);
z(i) = x(imod);
end
xpadded = [x z];
end
fflip = reverse(sf);
ypadded = filter(fflip,1,xpadded);
if p < n,
y = [ypadded((n+1):(n+p)) ypadded((p+1):(n))];
else
for i=1:n,
imod = 1 + rem(p+i-1,n);
y(imod) = ypadded(p+i);
end
end
shift = (p-1)/ 2 ;
shift = 1 + rem(shift-1, n);
y = [y((1+shift):n) y(1:(shift))] ;
%
% Copyright (c) 1995. Shaobing Chen and David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function d = DownDyadHi_PBS(x,qmf)
% DownDyadHi_PBS -- Hi-Pass Downsampling operator (periodized,symmetric)
% Usage
% d = DownDyadHi_PBS(x,sqmf)
% Inputs
% x 1-d signal at fine scale
% sqmf symmetric filter
% Outputs
% y 1-d signal at coarse scale
%
% See Also
% DownDyadLo_PBS, UpDyadHi_PBS, UpDyadLo_PBS, FWT_PBS, symm_iconv
%
d = symm_iconv( MirrorSymmFilt(qmf),lshift(x));
n = length(d);
d = d(1:2:(n-1));
%
% Copyright (c) 1995. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = MirrorSymmFilt(x)
% MirrorSymmFilt -- apply (-1)^t modulation to symmetric filter
% Usage
% h = MirrorSymmFilt(l)
% Inputs
% l symmetric filter
% Outputs
% h symmetric filter with DC frequency content shifted
% to Nyquist frequency
%
% Description
% h(t) = (-1)^t * x(t), -k <= t <= k ; length(x)=2k+1
%
% See Also
% DownDyadHi_PBS
%
k = (length(x)-1)/2;
y = ( (-1).^((-k):k) ) .*x;
%
% Copyright (c) 1993. Iain M. Johnstone
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = symm_iconv(sf,x)
% symm_iconv -- Symmetric Convolution Tool for Two-Scale Transform
% Usage
% y = iconv(sf,x)
% Inputs
% sf symmetric filter
% x 1-d signal
% Output
% y filtered result
%
% Description
% Filtering by periodic convolution of x with sf
%
% See Also
% symm_aconv, UpDyadHi_PBS, UpDyadLo_PBS, DownDyadHi_PBS, DownDyadLo_PBS
%
n = length(x);
p = length(sf);
if p <= n,
xpadded = [x((n+1-p):n) x];
else
z = zeros(1,p);
for i=1:p,
imod = 1 + rem(p*n -p + i-1,n);
z(i) = x(imod);
end
xpadded = [z x];
end
ypadded = filter(sf,1,xpadded);
y = ypadded((p+1):(n+p));
shift = (p+1)/2;
shift = 1 + rem(shift-1, n);
y = [y(shift:n) y(1:(shift-1))];
%
% Copyright (c) 1995. Shaobing Chen and David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function x = IWT_SBS(wc,L,qmf,dqmf)
% iwt_po -- Inverse Wavelet Transform (symmetric extension, biorthogonal, symmetric)
% Usage
% x = IWT_SBS(wc,L,qmf,dqmf)
% Inputs
% wc 1-d wavelet transform: length(wc)= 2^J.
% L Coarsest scale (2^(-L) = scale of V_0); L << J;
% qmf quadrature mirror filter
% dqmf dual quadrature mirror filter (symmetric, dual of qmf)
% Outputs
% x 1-d signal reconstructed from wc
% Description
% Suppose wc = FWT_SBS(x,L,qmf,dqmf) where qmf and dqmf are orthonormal
% quad. mirror filters made by MakeBioFilter. Then x can be reconstructed
% by
% x = IWT_SBS(wc,L,qmf,dqmf)
% See Also:
% FWT_SBS, MakeBioFilter
%
wcoef = ShapeAsRow(wc);
[n,J] = dyadlength(wcoef);
dp = dyadpartition(n);
x = wcoef(1:dp(L+1));
for j=L:J-1,
dyadj = (dp(j+1)+1):dp(j+2);
x = UpDyad_SBS(x, wcoef(dyadj), qmf, dqmf);
end
x = ShapeLike(x,wc);
%
% Copyright (c) 1996. Thomas P.Y. Yu
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function x = UpDyad_SBS(beta,alpha,qmf,dqmf)
% UpDyad_SBS -- Symmetric Upsampling operator
% Usage
% x = UpDyad_SBS(beta,alpha,qmf,dqmf)
% Inputs
% beta coarse coefficients
% alpha fine coefficients
% qmf quadrature mirror filter
% dqmf dual quadrature mirror filter
% Outputs
% x 1-d signal at fine scale
% See Also
% DownDyad_SBS, IWT_SBS
%
% oddf = (rem(length(qmf),2)==1);
oddf = ~(qmf(1)==0 & qmf(length(qmf))~=0);
oddx = (length(beta) ~= length(alpha));
L = length(beta)+length(alpha);
if oddf,
if oddx,
ebeta = extend(beta,1,1);
ealpha = extend(alpha,2,2);
else
ebeta = extend(beta,2,1);
ealpha = extend(alpha,1,2);
end
else
if oddx,
ebeta = extend(beta,1,2);
ealpha = [alpha 0 -reverse(alpha)];
else
ebeta = extend(beta,2,2);
ealpha = [alpha -reverse(alpha)];
end
end
coarse = UpDyadLo_PBS(ebeta,dqmf);
fine = UpDyadHi_PBS(ealpha,qmf);
x = coarse + fine;
x = x(1:L);
%
% Copyright (c) 1996. Thomas P.Y. Yu
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = UpDyadLo_PBS(x,qmf)
% UpDyadLo_PBS -- Lo-Pass Upsampling operator; periodized
% Usage
% u = UpDyadLo_PBS(d,sf)
% Inputs
% d 1-d signal at coarser scale
% sf symmetric filter
% Outputs
% u 1-d signal at finer scale
%
% See Also
% DownDyadLo_PBS , DownDyadHi_PBS , UpDyadHi_PBS, IWT_PBS, symm_iconv
%
y = symm_iconv(qmf, UpSample(x,2) );
%
% Copyright (c) 1995. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function y = UpDyadHi_PBS(x,qmf)
% UpDyadHi_PBS -- Hi-Pass Upsampling operator; periodized
% Usage
% u = UpDyadHi_PBS(d,f)
% Inputs
% d 1-d signal at coarser scale
% sf symmetric filter
% Outputs
% u 1-d signal at finer scale
%
% See Also
% DownDyadLo_PBS, DownDyadHi_PBS, UpDyadLo_PBS, IWT_PBS, symm_aconv
%
y = symm_aconv( MirrorSymmFilt(qmf), rshift( UpSample(x,2) ) );
%
% Copyright (c) 1995. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function wc = FWT2_SBS(x,L,qmf,dqmf)
% FWT2_SBS -- 2-dimensional wavelet transform
% (symmetric extension, bi-orthogonal)
% Usage
% wc = FWT2_SBS(x,L,qmf,dqmf)
% Inputs
% x 2-d image (n by n array, n arbitrary)
% L coarsest level
% qmf low-pass quadrature mirror filter
% dqmf high-pass dual quadrature mirror filter
% Output
% wc 2-d wavelet transform
% Description
% A two-dimensional Wavelet Transform is computed for the
% matrix x. To reconstruct, use IWT2_SBS.
% See Also
% IWT2_SBS
%
[m,J] = dyadlength(x(:,1));
[n,K] = dyadlength(x(1,:));
wc = x;
mc = m;
nc = n;
J = min([J,K]);
for jscal=J-1:-1:L,
if rem(mc,2)==0,
top = (mc/2+1):mc;
bot = 1:(mc/2);
else
top = ((mc+1)/2+1):mc;
bot = 1:((mc+1)/2);
end
if rem(nc,2)==0,
right = (nc/2+1):nc;
left = 1:(nc/2);
else
right = ((nc+1)/2+1):nc;
left = 1:((nc+1)/2);
end
for ix=1:mc,
row = wc(ix,1:nc);
[beta,alpha] = DownDyad_SBS(row,qmf,dqmf);
wc(ix,left) = beta;
wc(ix,right) = alpha;
end
for iy=1:nc,
column = wc(1:mc,iy)';
[beta,alpha] = DownDyad_SBS(column,qmf,dqmf);
wc(bot,iy) = beta';
wc(top,iy) = alpha';
end
mc = bot(length(bot));
nc = left(length(left));
end
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function x = IWT2_SBS(wc,L,qmf,dqmf)
% IWT2_SBS -- Inverse 2d Wavelet Transform
% (symmetric extention, bi-orthogonal)
% Usage
% x = IWT2_SBS(wc,L,qmf,dqmf)
% Inputs
% wc 2-d wavelet transform [n by n array, n arbitrary]
% L coarse level
% qmf low-pass quadrature mirror filter
% dqmf high-pas dual quadrature mirror filter
% Outputs
% x 2-d signal reconstructed from wc
% Description
% If wc is the result of a forward 2d wavelet transform, with
% wc = FWT2_SBS(x,L,qmf,dqmf)
% then x = IWT2_SBS(wc,L,qmf,dqmf) reconstructs x exactly if qmf is a nice
% quadrature mirror filter, e.g. one made by MakeBioFilter
% See Also:
% FWT2_SBS, MakeBioFilter
%
[m,J] = dyadlength(wc(:,1));
[n,K] = dyadlength(wc(1,:));
% assume m==n, J==K
x = wc;
dpm = dyadpartition(m);
for jscal=L:J-1,
bot = 1:dpm(jscal+1);
top = (dpm(jscal+1)+1):dpm(jscal+2);
all = [bot top];
nc = length(all);
for iy=1:nc,
x(all,iy) = UpDyad_SBS(x(bot,iy)', x(top,iy)', qmf, dqmf)';
end
for ix=1:nc,
x(ix,all) = UpDyad_SBS(x(ix,bot), x(ix,top), qmf, dqmf);
end
end
%
% Copyright (c) 1996. Thomas P.Y. Yu
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function wc = FWT2_PO(x,L,qmf)
% FWT2_PO -- 2-d MRA wavelet transform (periodized, orthogonal)
% Usage
% wc = FWT2_PO(x,L,qmf)
% Inputs
% x 2-d image (n by n array, n dyadic)
% L coarse level
% qmf quadrature mirror filter
% Outputs
% wc 2-d wavelet transform
%
% Description
% A two-dimensional Wavelet Transform is computed for the
% array x. To reconstruct, use IWT2_PO.
%
% See Also
% IWT2_PO, MakeONFilter
%
[n,J] = quadlength(x);
wc = x;
nc = n;
for jscal=J-1:-1:L,
top = (nc/2+1):nc; bot = 1:(nc/2);
for ix=1:nc,
row = wc(ix,1:nc);
wc(ix,bot) = DownDyadLo(row,qmf);
wc(ix,top) = DownDyadHi(row,qmf);
end
for iy=1:nc,
row = wc(1:nc,iy)';
wc(top,iy) = DownDyadHi(row,qmf)';
wc(bot,iy) = DownDyadLo(row,qmf)';
end
nc = nc/2;
end
%
% Copyright (c) 1993. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function x = IWT2_PO(wc,L,qmf)
% IWT2_PO -- Inverse 2-d MRA wavelet transform (periodized, orthogonal)
% Usage
% x = IWT2_PO(wc,L,qmf)
% Inputs
% wc 2-d wavelet transform [n by n array, n dyadic]
% L coarse level
% qmf quadrature mirror filter
% Outputs
% x 2-d signal reconstructed from wc
%
% Description
% If wc is the result of a forward 2d wavelet transform, with
% wc = FWT2_PO(x,L,qmf), then x = IWT2_PO(wc,L,qmf) reconstructs x
% exactly if qmf is a nice qmf, e.g. one made by MakeONFilter.
%
% See Also
% FWT2_PO, MakeONFilter
%
[n,J] = quadlength(wc);
x = wc;
nc = 2^(L+1);
for jscal=L:J-1,
top = (nc/2+1):nc; bot = 1:(nc/2); all = 1:nc;
for iy=1:nc,
x(all,iy) = UpDyadLo(x(bot,iy)',qmf)' ...
+ UpDyadHi(x(top,iy)',qmf)';
end
for ix=1:nc,
x(ix,all) = UpDyadLo(x(ix,bot),qmf) ...
+ UpDyadHi(x(ix,top),qmf);
end
nc = 2*nc;
end
%
% Copyright (c) 1993. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function [n,J] = quadlength(x)
% quadlength -- Find length and dyadic length of square matrix
% Usage
% [n,J] = quadlength(x)
% Inputs
% x 2-d image; size(n,n), n = 2^J (hopefully)
% Outputs
% n length(x)
% J least power of two greater than n
%
% Side Effects
% A warning message is issue if n is not a power of 2,
% or if x is not a square matrix.
%
s = size(x);
n = s(1);
if s(2) ~= s(1),
disp('Warning in quadlength: nr != nc')
end
k = 1 ; J = 0; while k < n , k=2*k; J = 1+J ; end ;
if k ~= n ,
disp('Warning in quadlength: n != 2^J')
end
%
% Copyright (c) 1993. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function wp = FWT_TI(x,L,qmf)
% FWT_TI -- translation invariant forward wavelet transform
% Usage
% TIWT = FWT_TI(x,L,qmf)
% Inputs
% x array of dyadic length n=2^J
% L degree of coarsest scale
% qmf orthonormal quadrature mirror filter
% Outputs
% TIWT stationary wavelet transform table
% formally same data structure as packet table
%
% See Also
% IWT_TI
%
[n,J] = dyadlength(x);
D = J-L;
wp = zeros(n,D+1);
x = ShapeAsRow(x);
%
wp(:,1) = x';
for d=0:(D-1),
for b=0:(2^d-1),
s = wp(packet(d,b,n),1)';
hsr = DownDyadHi(s,qmf);
hsl = DownDyadHi(rshift(s),qmf);
lsr = DownDyadLo(s,qmf);
lsl = DownDyadLo(rshift(s),qmf);
wp(packet(d+1,2*b ,n),d+2) = hsr';
wp(packet(d+1,2*b+1,n),d+2) = hsl';
wp(packet(d+1,2*b ,n),1 ) = lsr';
wp(packet(d+1,2*b+1,n),1 ) = lsl';
end
end
%
% Copyright (c) 1994. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function tiwt = FWT2_TI(x,L,qmf)
% FWT_TI -- 2-D translation invariant forward wavelet transform
% Usage
% TIWT = FWT2_TI(x,L,qmf)
% Inputs
% x 2-d image (n by n real array, n dyadic)
% L degree of coarsest scale
% qmf orthonormal quadrature mirror filter
% Outputs
% TIWT translation-invariant wavelet transform table, (3*(J-L)+1)*n by n
%
% See Also
% IWT2_TI, IWT2_TIMedian
%
[n,J] = quadlength(x);
D = J-L;
tiwt = zeros((3*D+1)*n, n);
lastx = (3*D*n+1):(3*D*n+n); lasty = 1:n;
tiwt(lastx,lasty) = x;
%
for d=0:(D-1),
l = J-d-1; ns = 2^(J-d);
for b1=0:(2^d-1), for b2=0:(2^d-1),
s = tiwt(3*D*n+packet(d,b1,n), packet(d,b2,n));
wc00 = FWT2_PO(s,l,qmf);
wc01 = FWT2_PO(CircularShift(s,0,1),l,qmf);
wc10 = FWT2_PO(CircularShift(s,1,0),l,qmf);
wc11 = FWT2_PO(CircularShift(s,1,1),l,qmf);
index10 = packet(d+1,2*b1,n); index20 = packet(d+1,2*b2,n);
index11 = packet(d+1,2*b1+1,n); index21 = packet(d+1,2*b2+1,n);
% horizontal stuff
tiwt(3*d*n + index10 , index20) = wc00(1:(ns/2),(ns/2+1):ns);
tiwt(3*d*n + index11, index20) = wc01(1:(ns/2),(ns/2+1):ns);
tiwt(3*d*n + index10 , index21) = wc10(1:(ns/2),(ns/2+1):ns);
tiwt(3*d*n + index11 , index21) = wc11(1:(ns/2),(ns/2+1):ns);
% vertical stuff
tiwt((3*d+1)*n + index10 , index20) = wc00((ns/2+1):ns,1:(ns/2));
tiwt((3*d+1)*n + index11, index20) = wc01((ns/2+1):ns,1:(ns/2));
tiwt((3*d+1)*n + index10 , index21) = wc10((ns/2+1):ns,1:(ns/2));
tiwt((3*d+1)*n + index11 , index21) = wc11((ns/2+1):ns,1:(ns/2));
% diagonal stuff
tiwt((3*d+2)*n + index10 , index20) = wc00((ns/2+1):ns,(ns/2+1):ns);
tiwt((3*d+2)*n + index11, index20) = wc01((ns/2+1):ns,(ns/2+1):ns);
tiwt((3*d+2)*n + index10 , index21) = wc10((ns/2+1):ns,(ns/2+1):ns);
tiwt((3*d+2)*n + index11 , index21) = wc11((ns/2+1):ns,(ns/2+1):ns);
% low freq stuff
tiwt(3*D*n + index10 , index20) = wc00(1:(ns/2),1:(ns/2));
tiwt(3*D*n + index11, index20) = wc01(1:(ns/2),1:(ns/2));
tiwt(3*D*n + index10 , index21) = wc10(1:(ns/2),1:(ns/2));
tiwt(3*D*n + index11 , index21) = wc11(1:(ns/2),1:(ns/2));
end, end
end
%
% Copyright (c) 1995. David L. Donoho and Thomas P.Y. Yu
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function p=packet(d,b,n)
% packet -- Packet table indexing
% Usage
% p = packet(d,b,n)
% Inputs
% d depth of splitting in packet decomposition
% b block index among 2^d possibilities at depth d
% n length of signal
% Outputs
% p linear indices of all coeff's in that block
%
npack = 2^d;
p = ( (b * (n/npack) + 1) : ((b+1)*n/npack ) ) ;
%
% Copyright (c) 1993. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function x = IWT_TI(pkt,qmf)
% IWT_TI -- Invert translation invariant wavelet transform
% Usage
% x = IWT_TI(TIWT,qmf)
% Inputs
% TIWT translation-invariant wavelet transform table
% qmf quadrature mirror filter
% Outputs
% x 1-d signal reconstructed from translation-invariant
% transform TIWT
%
% See Also
% FWT_TI
%
[n,D1] = size(pkt);
D = D1-1;
J = log2(n);
L = J-D;
%
wp = pkt;
%
sig = wp(:,1)';
for d= D-1:-1:0,
for b=0:(2^d-1)
hsr = wp(packet(d+1,2*b ,n),d+2)';
hsl = wp(packet(d+1,2*b+1,n),d+2)';
lsr = sig(packet(d+1,2*b ,n) );
lsl = sig(packet(d+1,2*b+1,n) );
loterm = (UpDyadLo(lsr,qmf) + lshift(UpDyadLo(lsl,qmf)))/2;
hiterm = (UpDyadHi(hsr,qmf) + lshift(UpDyadHi(hsl,qmf)))/2;
sig(packet(d,b,n)) = loterm+hiterm;
end
end
x = sig;
%
% Copyright (c) 1994. David L. Donoho
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function x = IWT2_TI(tiwt,L,qmf)
% IWT2_TI -- Invert 2-d translation invariant wavelet transform
% Usage
% x = IWT2_TI(TIWT,qmf)
% Inputs
% TIWT translation-invariant wavelet transform table, (3*(J-L)+1)*n by n
% L degree of coarsest scale
% qmf quadrature mirror filter
% Outputs
% x 2-d image reconstructed from translation-invariant transform TIWT
%
% See Also
% FWT2_TI, IWT2_TIMedian
%
[D1,n] = size(tiwt);
J = log2(n);
D = J-L;
%
lastx = (3*D*n+1):(3*D*n+n); lasty = 1:n;
x = tiwt(lastx,lasty);
for d=(D-1):-1:0,
l = J-d-1; ns = 2^(J-d);
for b1=0:(2^d-1), for b2=0:(2^d-1),
index10 = packet(d+1,2*b1,n); index20 = packet(d+1,2*b2,n);
index11 = packet(d+1,2*b1+1,n); index21 = packet(d+1,2*b2+1,n);
wc00 = [x(index10,index20) tiwt(3*d*n+index10,index20) ; ...
tiwt((3*d+1)*n+index10,index20) tiwt((3*d+2)*n+index10,index20)];
wc01 = [x(index11,index20) tiwt(3*d*n+index11,index20) ; ...
tiwt((3*d+1)*n+index11,index20) tiwt((3*d+2)*n+index11,index20)];
wc10 = [x(index10,index21) tiwt(3*d*n+index10,index21) ; ...
tiwt((3*d+1)*n+index10,index21) tiwt((3*d+2)*n+index10,index21)];
wc11 = [x(index11,index21) tiwt(3*d*n+index11,index21) ; ...
tiwt((3*d+1)*n+index11,index21) tiwt((3*d+2)*n+index11,index21)];
x(packet(d,b1,n), packet(d,b2,n)) = ( IWT2_PO(wc00,l,qmf) + ....
CircularShift(IWT2_PO(wc01,l,qmf),0,-1) + ...
CircularShift(IWT2_PO(wc10,l,qmf),-1,0) + ...
CircularShift(IWT2_PO(wc11,l,qmf),-1,-1) ) / 4;
end, end
end
%
% Copyright (c) 1995. David L. Donoho and Thomas P.Y. Yu
%
%
% Part of WaveLab Version 802
% Built Sunday, October 3, 1999 8:52:27 AM
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
%
function result = CircularShift(matrix, colshift, rowshift)
% CIRCULARSHIFT: Circular shifting of a matrix/image, i.e., pixels that get
% shifted off one side of the image are put back on the other side.
%
% result = circularShift(matrix, colshift, rowshift)
%
% EPS, DJH '96
lastrow = size(matrix, 1);
lastcol = size(matrix, 2);
result = matrix;
% Shift the cols
if (colshift>0)
result = [result(:,[lastcol-colshift+1:lastcol]) ...
result(:,[1:lastcol-colshift])];
else
colshift = -colshift;
result = [result(:,[colshift+1:lastcol]) ...
result(:,[1:colshift])];
end
% Shift the rows
if (rowshift>0)
result = [result([lastrow-rowshift+1:lastrow],:) ; ...
result([1:lastrow-rowshift],:)];
else
rowshift = -rowshift;
result = [result([rowshift+1:lastrow],:) ; ...
result([1:rowshift],:)];
end
function x = reverse(x)
x = x(end:-1:1);
function StatWT = TI2Stat(TIWT)
% TI2Stat -- Convert Translation-Invariant Transform to Stationary Wavelet Transform
% Usage
% StatWT = TI2Stat(TIWT)
% Inputs
% TIWT translation invariant table from FWT_TI
% Outputs
% StatWT stationary wavelet transform table table as FWT_Stat
%
% See Also
% Stat2TI, FWT_TI, FWT_Stat
%
StatWT = TIWT;
[n,D1] = size(StatWT);
D = D1-1;
J = log2(n);
L = J-D;
%
index = 1;
for d=1:D,
nb = 2^d;
nk = n/nb;
index = [ (index+nb/2); index];
index = index(:)';
for b= 0:(nb-1),
StatWT(d*n + (index(b+1):nb:n)) = TIWT(d*n + packet(d,b,n));
end
end
for b= 0:(nb-1),
StatWT((index(b+1):nb:n)) = TIWT(packet(d,b,n));
end
%
% Copyright (c) 1994. Shaobing Chen
%
function TIWT = Stat2TI(StatWT)
% Stat2TI -- Convert Stationary Wavelet Transform to Translation-Invariant Transform
% Usage
% TIWT = Stat2TI(StatWT)
% Inputs
% StatWT stationary wavelet transform table as FWT_Stat
% Outputs
% TIWT translation-invariant transform table as FWT_TI
%
% See Also
% Stat2TI, FWT_TI, FWT_Stat
%
TIWT = StatWT;
[n,D1] = size(StatWT);
D = D1-1;
index = 1;
for d=1:D,
nb = 2^d;
nk = n/nb;
index = [ (index+nb/2); index];
index = index(:)';
for b= 0:(nb-1),
TIWT(d*n + packet(d,b,n)) = StatWT(d*n + (index(b+1):nb:n));
end
end
for b= 0:(nb-1),
TIWT(packet(d,b,n)) = StatWT((index(b+1):nb:n));
end
%
% Copyright (c) 1994. Shaobing Chen
%
%
% Part of Wavelab Version 850
% Built Tue Jan 3 13:20:40 EST 2006
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail wavelab@stat.stanford.edu
function d = nb_dims(x)
% nb_dims - debugged version of ndims.
%
% d = nb_dims(x);
%
% Copyright (c) 2004 Gabriel Peyr
if isempty(x)
d = 0;
return;
end
d = ndims(x);
if d==2 && (size(x,1)==1 || size(x,2)==1)
d = 1;
end
