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我已經看到了3種gabor濾波器方程（複數，實數，虛數），但我仍然對這裏實現的方程式感到困惑？有人能告訴我瞭解Gabor濾波器組
- 什麼是fu？
- 爲什麼fmax = 0.25（它是什麼？）？
- 這裏使用哪個方程（gFilter（x，y））？
- 爲什麼eta & gama = sqrt（2）？
[功能gaborArray = gaborFilterBank（U，V，M，N）
% GABORFILTERBANK generates a custum Gabor filter bank.
% It creates a u by v cell array, whose elements are m by n matrices;
% each matrix being a 2-D Gabor filter.
%
%
% Inputs:
%u : No. of scales (usually set to 5)
%v : No. of orientations (usually set to 8)
% m : No. of rows in a 2-D Gabor filter (an odd integer number,
%usually set to 39)
% n : No. of columns in a 2-D Gabor filter (an odd integer number,
%usually set to 39)
%
% Output:
% gaborArray: A u by v array, element of which are m by n
% matries; each matrix being a 2-D Gabor filter
%
%
% Sample use:
%
% gaborArray = gaborFilterBank(5,8,39,39);
%
if (nargin ~= 4) % Check correct number of arguments
error('There must be four input arguments (Number of scales and
orientations and the 2-D size of the filter)!')
end
%% Create Gabor filters
% Create u*v gabor filters each being an m by n matrix
m=double(int32(m));
n=double(int32(n));
gaborArray = cell(u,v);
fmax = 0.25;
gama = sqrt(2);
eta = sqrt(2);
for i = 1:u
fu = fmax/((sqrt(2))^(i-1));
alpha = fu/gama;
beta = fu/eta;
for j = 1:v
tetav = ((j-1)/v)*pi;
gFilter = zeros(m,n);
for x = 1:m
for y = 1:n
xprime = (x-((m+1)/2))*cos(tetav)+(y-((n+1)/2))*sin(tetav);
yprime = -(x-((m+1)/2))*sin(tetav)+(y-((n+1)/2))*cos(tetav);
gFilter(x,y) = (fu^2/(pi*gama*eta))*exp(-((alpha^2)*(xprime^2)+(beta^2)*(yprime^2)))*exp(1i*2*pi*fu*xprime);
end
end
gaborArray{i,j} = gFilter;
end
end