www.pudn.com > SPIHT_bandelet.rar > perform_warped_wavelet.m

function M = perform_warped_wavelet(M,theta,dir) 
 
% perform_warped_wavelet - perform a warped haar transform 
% 
%   MW = perform_warped_wavelet(M,theta,dir); 
% 
%   Copyright (c) 2005 Gabriel Peyré 
 
if theta==Inf   % special token : no geometry 
    return; % nothing to do 
end 
 
if nargin<3 
    dir = 1; 
end 
 
if size(M,3)>1 
    for i=1:size(M,3) 
        M(:,:,i) = perform_warped_wavelet(M(:,:,i),theta,dir); 
    end 
    return; 
end 
 
n = size(M,1); 
% sampling location 
[Y,X] = meshgrid(1:n,1:n); 
% projection on orthogonal direction 
t = -sin(theta)*X(:) + cos(theta)*Y(:); 
% order points in increasing order 
[tmp,I] = sort(t); 
Jmin = 1; 
M(I) = perform_wavelet_transform(M(I),Jmin,dir);