设计Gabor滤波银行在傅立叶域

Question

我试图利用Matlab软件下面的代码设计在傅立叶域Gabor滤波器银行：

for i=1:u 
for j = 1:v 
    theta =theta_list(j); 
    w_1_x=(centerFreq(1,i)*((m+1)/2)*cos(theta)); % size of filter and image is m-by-n 
    w_1_y=(centerFreq(2,i)*((n+1)/2)*sin(theta)); 
    w_2_x=(-centerFreq(1,i)*((m+1)/2)*cos(theta)); 
    w_2_y=(-centerFreq(2,i)*((n+1)/2)*sin(theta)); 
    sigma=sqrt((w_1_x)^2+(w_1_y)^2); 
    sigma_H=sigma/(2*pi); 
    gF=fspecial('gaussian', [m,n], sigma_H); 
    gFilter1=circshift(gF, [round(w_1_x), round(w_1_y)]); 
    gFilter2=circshift(gF, [round(w_2_x), round(w_2_y)]); 
    gaborArray1{i,j} = 0.5*gFilter1+0.5*gFilter2; 
    gaborArray2{i,j} = 0.5*1i*gFilter1-0.5*1i*gFilter2; 
    gaborFilterBank{i,j}=gaborArray1{i,j}+1i.*gaborArray2{i,j}; 
end 
end 

然而，当我变换过滤器的图像域使用下面的代码和可视化的滤波器的相位图：

filter=ifft2(ifftshift(gaborFilterBank{i,j})); 
phase=zeros(m, n); 
for p=1:m 
for q=1:n 
    phase(p,q)=atan(imag(filter(p,q)/real(filter(p,q))); 
    end 
end 
figure, imshow(phase, []); 

得到奇怪模式在过滤器的中心（如图中附图）。请让我知道我的代码有什么问题？

Answer 1

我发现了这个问题。我不应该把中心坐标乘以[（m + 1）/ 2，（n + 1）/ 2]，而应该乘以[m，n]。更具体地讲，而不是：

w_1_x=(centerFreq(1,i)*((m+1)/2)*cos(theta)); % size of filter and image is m-by-n 
w_1_y=(centerFreq(2,i)*((n+1)/2)*sin(theta)); 
w_2_x=(-centerFreq(1,i)*((m+1)/2)*cos(theta)); 
w_2_y=(-centerFreq(2,i)*((n+1)/2)*sin(theta)); 

它应该是：

w_1_x=(centerFreq(1,i)*m*cos(theta)); % size of filter and image is m-by-n 
w_1_y=(centerFreq(2,i)*n*sin(theta)); 
w_2_x=(-centerFreq(1,i)*m*cos(theta)); 
w_2_y=(-centerFreq(2,i)*n*sin(theta));