fftencode.m

数字图像的压缩技术

%function DCTencoding(InitialImage,Snum)
%  InitialImage------
%  Snum--------------
%
rat=1/4;
clear  
InitialImage=imread('lena.bmp');
%
InitialImage=double(InitialImage)/255;
%  
figure(1);
imshow(InitialImage);
title('原始图像');
%
DCTCoe=blkproc(InitialImage,[16 16],'fft2(x)');
%
CoeVar=im2col(DCTCoe,[16 16],'distinct');
Coe=CoeVar;
%
[Y,Ind]=sort(CoeVar);  
%
[m,n]=size(CoeVar);
Snum=256-256*rat;;
for i=1:n
   Coe(Ind(1:Snum),i)=0;
end
%
B2=col2im(Coe,[16 16],[256 256],'distinct');
%
I2=blkproc(B2,[16 16],'ifft2(x)');
%
figure(2);
imshow(I2);
% 计算归一化图像的均方误差
error=InitialImage.^2-I2.^2;
MSE=sum(error(:))/prod(size(I2))