gaussianhighpass.m

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

clear all
clc
a=imread('Fig0457(a)(thumb_print).tif');
a=double(a);
c=size(a);
N=c(1)
D0=input('Enter the cutoff frequency/standard deviation ');
for u=1:1:c(1)
    for v=1:1:c(2)
        Dx=((u-(N/2))^2+(v-(N/2))^2)^0.5;
        D=Dx*Dx;
        H(u,v)=1-exp(-D/(2*D0*D0));
    end
end
vv=fft2(a);
vc=fftshift(vv);
x=vc.*H;
X=abs(ifft2(x));
figure(1),imshow(uint8(a)),title('Original Image')
figure(2),mesh(H),title('Gaussian filter response')
figure(3),imshow(uint8(X)),title('gaussian High pass filtered Image')
figure(4),imagesc(H),colormap(gray),title('2D Gaussian Filter')