From 34de475999a22ac7280411e15339e77a0c8dbc2e Mon Sep 17 00:00:00 2001
From: Joe Zhao <ztuowen@gmail.com>
Date: Tue, 12 May 2015 13:15:55 +0800
Subject: initial commit

---
 gabor_fn.m | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 gabor_fn.m

(limited to 'gabor_fn.m')

diff --git a/gabor_fn.m b/gabor_fn.m
new file mode 100644
index 0000000..effc0ba
--- /dev/null
+++ b/gabor_fn.m
@@ -0,0 +1,27 @@
+function gb=gabor_fn(bw,gamma,psi,lambda,theta)
+% bw    = bandwidth, (1)
+% gamma = aspect ratio, (0.5)
+% psi   = phase shift, (0)
+% lambda= wave length, (>=2)
+% theta = angle in rad, [0 pi)
+ 
+sigma = lambda/pi*sqrt(log(2)/2)*(2^bw+1)/(2^bw-1);
+sigma_x = sigma;
+sigma_y = sigma/gamma;
+
+sz=fix(8*max(sigma_y,sigma_x));
+if mod(sz,2)==0, sz=sz+1;end
+
+% alternatively, use a fixed size
+% sz = 60;
+ 
+[x y]=meshgrid(-fix(sz/2):fix(sz/2),fix(sz/2):-1:fix(-sz/2));
+% x (right +)
+% y (up +)
+
+% Rotation 
+x_theta=x*cos(theta)+y*sin(theta);
+y_theta=-x*sin(theta)+y*cos(theta);
+ 
+gb=exp(-0.5*(x_theta.^2/sigma_x^2+y_theta.^2/sigma_y^2)).*cos(2*pi/lambda*x_theta+psi);
+imshow(gb/2+0.5);
\ No newline at end of file
-- 
cgit v1.2.3-70-g09d2