How to create 64 Gabor features at each scale and orientation in the spatial and frequency domain

Question

Normally, a Gabor filter, as its name suggests, is used to filter an image and extract everything that it is oriented in the same direction of the filtering.

Answer 1

In the frequency domain:

sigma_u=1/2*pi*sigmaq;
sigma_v=1/2*pi*sigmaq;
u0=2*pi*cos(theta)*lambda(k);
v0=2*pi*sin(theta)*lambda(k);

for u = -filtSizeL:filtSizeR
            for v = -filtSizeL:filtSizeR

                if ( sqrt(u^2+v^2)>filtSize/2 )
                    E = 0;
                else
                    v_theta = u*cos(theta) - v*sin(theta);
                    u_theta = u*sin(theta) + v*cos(theta);

                  E=(1/2*pi*sigma_u*sigma_v)*((exp((-1/2)*(((u_theta-u0)^2/sigma_u^2))+((v_theta-v0)^2/sigma_v^2))) + (exp((-1/2)*(((u_theta+u0)^2/sigma_u^2))+((v_theta+v0)^2/sigma_v^2))));

                end
                f(v+center,u+center) = E;
            end
        end