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

% test the quadtree construction in wavelet domain 
% 
%   Copyright (c) 2005 Gabriel Peyr? 
 
% set to 0 if you don't want to save the images 
save_images = 0; 
 
rep = 'images/'; 
warning off; 
mkdir(rep); 
warning on; 
 
n = 128; 
 
options.sigma = 3; 
M = load_image('line_circle', n); 
if save_images 
    warning off; 
    imwrite( M/256, [rep 'original.png'], 'png' ) 
    warning on; 
end 
 
Jmin = 3; 
Jmax = log2(n)-1; 
j_min = 2; 
j_max = 4; 
T = 100; 
disp('Computing quadtree.'); 
[QT,Theta] = compute_wavelet_quadtree(M,Jmin,T,j_min,j_max); 
 
 
MW = perform_wavelet_transform(M,Jmin, 1); 
 
% save QT and Theta 
if save_images 
    warning off; 
    imwrite( (QT-min(QT(:)))/(max(QT(:))-min(QT(:))), [rep sprintf('qt_bandelet_wavelet_%d_m%d.png', T,m)], 'png' ); 
    imwrite( Theta/pi, [rep sprintf('theta_bandelet_wavelet_%d_m%d.png', T,m)], 'png' ); 
    warning on; 
 
     
    str = [rep sprintf('quadtree_wavelet_bandelet_%d', T)]; 
    clf; 
    plot_wavelet_quadtree(QT,Theta,Jmax,1,MW); 
    saveas(gcf, str, 'png'); 
 
    clf; 
    plot_wavelet_quadtree(QT,Theta,Jmax,1,MW,2); 
    saveas(gcf, [str, '_geom'], 'eps'); 
     
    clf; 
    plot_wavelet_quadtree(QT,Theta,Jmax,1,MW,3); 
    saveas(gcf, [str, '_struct'], 'eps'); 
end 
 
% direct transform 
disp('Computing forward bandelet transform.'); 
[MB,m_geom] = perform_wavelet_bandelet_transform(M,Jmin,QT,Theta,1); 
 
disp('Computing inverse bandelet transform.'); 
[M1,m_geom] = perform_wavelet_bandelet_transform(MB,Jmin,QT,Theta,-1); 
 
disp( ['|f-B^-1(B(f)|^2 (should be 0 for a correct reconstruction) --> ' sprintf( '%f', sum( (M(:)-M1(:)).^2 ) )] ); 
 
% performing truncated reconstruction 
MBt = MB .* (abs(MB)>T);	% thresholded transform 
[M1,m_geom] = perform_wavelet_bandelet_transform(MBt,Jmin,QT,Theta,-1); 
clf; 
imagesc(M1); 
% number of coefficients used 
m = round( sum( abs(MB(:))>T )+m_geom ); 
 
 
% save image 
if save_images 
    warning off; 
    imwrite( M1/256, [rep sprintf('bandelet_wavelet_%d_m%d.png', T,m)], 'png' ); 
    disp( sprintf('T=%d, #coefficients=%d', T, m) ); 
    warning on; 
end