im = im2double(imread('C:\Users\air\Desktop\2.jpg')); M = size(im,1); h = fspecial('gaussian',5,1); imb = filter2(h,im)+rand(M,M)/10; figure; subplot(121); imshow(imb); subplot(122); imshow(im); Y = fft2(imb); H = fft2(h,M,M); invH = 1./H; idx = find(abs(H)