fourier1.m

Image enhancement in frequency domain using Fourier center frequency, Gaussian lowpass filter, Low p

clear all
clc
aa = imread('Fig0458(a)(blurry_moon).tif');
a=double(aa);
b=abs(fft2(a));
[row col]=size(a);
for x=1:1:row
    for y=1:1:col
        c(x,y)=a(x,y)*((-1)^(x+y));
    end
end
d=abs(fft2(c));
max_d=max(max(d));
min_d=min(min(d));
dynamic_range = max_d - min_d;
d_log = log(1+d);
%% plotting
figure(1),colormap(gray),imagesc(b)
figure(2),colormap(gray),imagesc(d)
figure(3),colormap(gray),imagesc(d_log)
figure(4),colormap(gray),imagesc(aa)