Gabor滤波器
close all;clear all;clc;G = cell(5,8);
for s = 1:5
for j = 1:8
G{s,j}=zeros(32,32);
end
end
for s = 1:5
for j = 1:8
G{s,9-j} = gabor(,(s-1),j-1,pi,sqrt(2),pi);
end
end
figure;
for s = 1:5
for j = 1:8
subplot(5,8,(s-1)*8+j);
imshow(real(G{s,j}),[]);
end
end
for s = 1:5
for j = 1:8
G{s,j}=fft2(G{s,j});
end
end
save gabor G
function Psi = gabor (w,nu,mu,Kmax,f,sig)
% w: Window
% nu : Scale ;
% mu : Orientation
% kmax = pi/2
% f = sqrt(2)
% sig = 2*pi
m = w(1);
n = w(2);
K = Kmax/f^nu * exp(i*mu*pi/8);
Kreal = real(K);
Kimag = imag(K);
NK = Kreal^2+Kimag^2;
Psi = zeros(m,n);
for x = 1:m
for y = 1:n
Z = ;
Psi(x,y) = (sig^(-2))*exp((-.5)*NK*(Z(1)^2+Z(2)^2)/(sig^2))*...
(exp(i**Z)-exp(-(sig^2)/2));
end
end
Gabor图像滤波器设计如下：
function = gabor_filter(I,Sx,Sy,U,V)
% 函数输入：
% I : 输入的二维图像
% Sx & Sy : 方差 along x and y-axes respectively
% U & V : 中心频率along x and y-axes respectively
% 函数输出：
% G : G（x，y）
% gabout : Gabor滤波图像
% G(x,y)表达式如下：
% 1 -1 x^ y^
%%% G(x,y) = ---------- * exp ([----{(----) 2+(----) 2}+2*pi*i*(Ux+Vy)])
% 2*pi*sx*sy 2 sx sy
if isa(I,'double')~=1
I = double(I);
end
for x = -fix(Sx):fix(Sx)
for y = -fix(Sy):fix(Sy)
G(fix(Sx)+x+1,fix(Sy)+y+1) = (1/(2*pi*Sx*Sy))*exp(-.5*((x/Sx)^2+(y/Sy)^2)+2*pi*i*(U*x+V*y));
end
end
Imgabout = conv2(I,double(imag(G)),'same');% 卷积
Regabout = conv2(I,double(real(G)),'same');% 卷积
gabout = uint8(sqrt(Imgabout.*Imgabout + Regabout.*Regabout)); % 输出滤波图像具体参考书籍：
余胜威，丁建明，吴婷，魏健蓝 . MATLAB图像滤波去噪分析及其应用. 北京：北京航空航天大学出版社，2015.
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