testgaussgradient.m

Gradient code. Use this to do gradient of image.

clc; clear all; close all;
im=imread('quadrado.bmp');
fim=mat2gray(im);

%[grad]=gradient(fim);

[imx imy]=gaussgradient(fim,0.05);
grad = abs(imx)+abs(imy);

G = fft2(grad);
F = fftshift(fft2(im));
z = size(F);
DF = zeros(z(1),z(2));
n = z(1);
for v = 1:n
   for u = 1:n
      DF(u,v) = i*(u+v).*F(u,v)/(n^2);
   end 
end
im1 = real(ifft2(G));
im2 = real(ifft2(DF));
subplot(121);
imshow(double(im1));
subplot(122);
imshow(double(im2));