te.m

该程序基于小波变换

%装载并显示原始图象
A=imread('C:\Documents and Settings\luom\My Documents\study\新建文件夹\江华荣（基于小波变换的弱信号提取）\程序\源程序\e.jpg');
subplot(2,2,1);
image(A);
%colormap(map);
%colorbar;
title('原始图象');
axis square;
%=============================================
%转换为索引图
A=double(A);
Xrgb=0.2990*A(:,:,1)+0.5870*A(:,:,2)+0.1140*A(:,:,3);
Nbcolors=255;
X=wcodemat(Xrgb,Nbcolors);
map=pink(Nbcolors);
subplot(2,2,1);
image(X);
colormap(map);
%colorbar;
title('原始图象');
axis square;
%=============================================
%加噪并显示图象
init=2055615866;
rand('seed',init);
XX=X+50*randn(size(X));
subplot(2,2,2);
image(XX);
colormap(map);
title('含噪图象');
axis square;
%===============================================
%对图象消噪
%用sym4小波函数对XX进行2层分解
[c,l]=wavedec2(XX,2,'sym4');
%实现低通滤波消噪
a1=wrcoef2('a',c,l,'sym4',1);
%再次实现低通滤波消噪
a2=wrcoef2('a',c,l,'sym4');
%==============================================
%显示消噪后的结果
subplot(2,2,3);
image(a1);
colormap(map);
title('第一次消噪图象');
axis square;
subplot(2,2,4);
image(a2);
colormap(map);
title('第二次消噪图象');
axis square;