Help with Image Processing Equation Implementation

I need help implementing the following equation in MATLAB:

This equation, multiplied by the Fourier transform of the image and then taking its inverse in going to output a blurred image. I'm having problem implementing it. This is what I have so far:

T = 1;
a = 0.1;
b = 0.1;

I=imread('5.26.tif');
I_fft=fft2(I);
[u,v]=size(I);

for i=1:u
    for j=1:v
        eq=((T)/(pi*(i*a + j*b)))*sin(pi*(i*a + j*b))*exp(-1*pi*(i*a + j*b));
        g(i,j)=eq;
    end
end

I_Blur =ifft2(g.*I_fft);

figure
imshow(I_Blur)

T, a and b are given parameters