matlab实例clearN=100f=zeros(50,50) f(15:35,23:28)=1 figure(1)imshow(f, notruesize )F=fft2(f,N,N) F2=fftshift(abs(F)) figure(2)x=1:N y=1:N mesh(x,y,F2(x,y)) colormap(gray) colorbar-matlab

f=zeros(30,30) f(5:24,13:17)=1 imshow(f, notruesize ) F=fft2(f,256,256) F2=fftshift(F) figure,imshow(log(abs(F2)),[-1 5], notruesize ) -f=zeros(30,30) f(5:24,13:17)=1 imshow(f, notruesize ) F=fft