更新时间:2022-03-09 16:23:59
我已经解决了这个问题.
I have solved this problem.
解决此问题的关键是功能ifftshow()
.
The key to solving this problem was the function ifftshow()
.
源代码
main.m
clear_all();
I = gray_imread('cameraman.png');
Dh = 10;
n = 1;
[J, K] = butterworth_hpf(I, Dh, n);
imshowpair(I, K, 'montage');
%draw_multiple_images({I, J, K});
ifftshow.m
function out = ifftshow(f)
f1 = abs(f);
fm = max(f1(:));
out = f1/fm;
end
butter_hp_kernel.m
function k = butter_hp_kernel(I, Dh, n)
Height = size(I,1);
Width = size(I,2);
[u, v] = meshgrid( ...
-floor(Width/2) :floor(Width-1)/2, ...
-floor(Height/2): floor(Height-1)/2 ...
);
k = butter_hp_f(u, v, Dh, n);
function f = butter_hp_f(u, v, Dh, n)
uv = u.^2+v.^2;
Duv = sqrt(uv);
frac = Dh./Duv;
%denom = frac.^(2*n);
A=0.414; denom = A.*(frac.^(2*n));
f = 1./(1.+denom);
butterworth_hpf.m
function [out1, out2] = butterworth_hpf(I, Dh, n)
Kernel = butter_hp_kernel(I, Dh, n);
I_ffted_shifted = fftshift(fft2(I));
I_ffted_shifted_filtered = I_ffted_shifted.*Kernel;
out1 = ifftshow(ifft2(I_ffted_shifted_filtered));
out2 = ifft2(ifftshift(I_ffted_shifted_filtered));
end