123.txt

图片压缩代码

Sig=imread('lena.bmp');
rat=8;
Sig=double(Sig)/256;
figure(1);
imshow(Sig);
title('原始图像');
T=dctmtx(8);
DCTcoe=blkproc(Sig,[8 8],'P1*x*P2',T,T');
coeVar=im2col(DCTcoe,[8 8],'distinct');
coe=coeVar;
[Y,Ind]=sort(coeVar);
[m,n]=size(coeVar);
Snum=64-64*rat;
for i=1:n
coe(Ind(1:Snum),i)=0;
end
B2=col2im(coe,[8 8],[256 256],'distinct');
I2=blkproc(B2,[8 8],'P1*x*P2',T',T);
figure(4);
imshow(I2);
title('压缩后的图像')