Gabor filter 2D

Generate a spatial gabor filter (2D)

gabor_filter = gabor2D(w, theta, sigma, size, type)
w : central frequency
theta : angle or orientation (degree)
sigma : sigma value of Gaussian envelope (usually choose = 1/w)
size : size of output filter in pixel (size*size)
type : 'even' or 'odd', default: 'odd';
'even' : real part of gabor filter
'odd' : imaginary part of gabor filter
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Example
Assume you want to filter the central frequency 32 of the image size
320*240 with filters size 31x31. It may be:
w = [2 4 8 16 32 64];
w = w/(320/31); % scale central frequency
theta = [0 45 90 135];
sigma = 1./w;
size = 31;
type = 'even';
g = gabor2D(w(5), theta(1), sigma(5), size, type);
showGabor(g);
** showGabor function just visualizes the output of gabor2D.