Edge detection using directional filter.

I have made a diamond filter of 29*29 and then sampled it by 512. here is the code,

close all
    clear all
    clc
  k=0.35;

    for n1=0:28
    for n2=0:28

       z1= (n1^2)-((n2^2)*(k^2));

       if n1==0 && n2==0
            h(n1+1,n2+1)=k/2;

     elseif n1~=0 && n2==0
            h(n1+1,n2+1)=(k*(cos(n1*pi)-1))/((n1^2)*(pi^2));

     elseif n2~=0 && z1==0
            h(n1+1,n2+1)=0;

     else
       A= k/(((n2^2)*(k^2)-n1^2)*pi^2);
       B= 1/(2*n2*pi^2);
       C= (cos(((n2*k)-n1)*pi))/((n2*k)+n1);
       D= (cos(((n2*k)+n1)*pi))/((n2*k)+n1);

             h(n1+1,n2+1)= A-(B*(C+D));
        end
    end
    end
    hf=fft2(h,512,512);
    hfn=max(max(abs(hf)));
    hflog=20*log10((abs(hf))/hfn);
    figure
    mesh(hflog)
    surf(hflog(1:end,1:end))

    %plot3(hf,1:512,1:512)
    %window function

    n1=28
     N= n1+1
     t=1:N
     w1=kaiser(N,4)
     w1f=fft(w1,512);

    %filter
    A=fwind1(hf,w1);
    freqz2(A)
    Af=fft2(A,512,512);
    figure
    Afa=abs(Af);
    surf(Afa(1:end,1:end))
    figure

    %image data
    I = imread ('LEENA.bmp');
    imshow(I)
    figure
    If=fft2(I);
    Ifa=abs(If);
    %operation

    U=imfilter(Ifa,Afa);
    Ui=ifft2(U);
    Uia=abs(Ui);
    imshow(Uia)

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i have taken a standard image of LEENA, and applied the filter 'A' , but am unable to get the result. Uia results in white image.|