figure12.m

来自「是一本教科书的各个章节的源程序代码,适合初学数字图像的人」· M 代码 · 共 36 行

load wbarb;
subplot(221); image(X); colormap(map)
title('原始图像');
axis square
disp('压缩前图像X的大小：');
whos('X')
[c,s]=wavedec2(X, 2, 'bior3.7');
ca1=appcoef2( c, s, 'bior3.7', 1);
ch1=detcoef2('h', c, s, 1);
cv1=detcoef2('v', c, s, 1);
cd1=detcoef2('d', c, s, 1);
a1=wrcoef2('a', c, s, 'bior3.7', 1);
h1=wrcoef2('h', c, s, 'bior3.7', 1);
v1=wrcoef2('v', c, s, 'bior3.7', 1);
d1=wrcoef2('d', c, s, 'bior3.7', 1);
c1=[a1, h1; v1, d1];
subplot(222); image(c1);
axis square
title('分解后低频和高频信息');
ca1=appcoef2(c, s, 'bior3.7',1);
ca1=wcodemat(ca1, 440, 'mat', 0);
ca1=0.5*ca1;
subplot(223); image(ca1); colormap(map);
axis square
title('第一次压缩图像');
disp('第一次压缩图像的大小为:');
whos('ca1')
ca2=appcoef2(c, s, 'bior3.7', 2);
ca2=wcodemat(ca2, 440, 'mat', 0);
ca2=0.25*ca2;
subplot(224); image(ca2); colormap(map);
axis square
title('第二次压缩图像');
disp('第二次压缩图像的大小为:');
whos('ca2')