close all;clear; f1 = imread('C:\Users\HP\Desktop\aaa\15.bmp') figure; subplot(331); imshow(f1); title('原图'); ft=fft2(f1); abs1=abs(ft); subplot(332); imshow(abs1,[]); title('傅里叶频谱'); subplot(333); imshow(log(abs1),[]) title('频谱拉伸'); fs=fftshift(ft); subplot(334); imshow(log(abs(fs)),[]); title('变化后的频谱图'); realf1=real(ifft2(ft)); subplot(335); imshow(realf1); title('傅里叶逆变换'); f2=imrotate(f1,45); subplot(336); imshow(f2); title('旋转'); ft2=fft2(f1); abs2=abs(ft2); subplot(337); imshow(log(abs2),[]) title('拉伸'); dt=dct2(f1); dttpic=log(abs(dt)); subplot(338); imshow(dt1,[]) title('离散余弦变换'); id=idct2(dt); subplot(339); imshow(id,[]) title('反变换');
close all;
clear;
f1 = imread('C:\Users\HP\Desktop\aaa\15.bmp');
figure;
subplot(331);
imshow(f1);
title('原图');
ft = fft2(f1);
abs1 = abs(ft);
subplot(332);
imshow(abs1,[]);
title('傅里叶频谱');
subplot(333);
imshow(log(abs1),[]);
title('频谱拉伸');
fs = fftshift(ft);
subplot(334);
imshow(log(abs(fs)),[]);
title('变化后的频谱图');
realf1 = ifft2(ft);
subplot(335);
imshow(abs(realf1), []);
title('傅里叶逆变换');
f2 = imrotate(f1, 45);
subplot(336);
imshow(f2);
title('旋转');
ft2 = fft2(f2);
abs2 = abs(ft2);
subplot(337);
imshow(log(abs2),[]);
title('拉伸');
dt = dct2(f1);
dttpic = log(abs(dt));
subplot(338);
imshow(dttpic, []);
title('离散余弦变换');
id = idct2(dt);
subplot(339);
imshow(id, []);
title('反变换');