gaborfilter.tar.gz_Gabor 指纹增强_One with You_gabor_gabor filter an

%%%%%%%VERSION 3 %%ANOTHER DESCRIBTION OF GABOR FILTER %The Gabor filter is basically a Gaussian (with variances sx and sy along x and y-axes respectively) %modulated by a complex sinusoid (with centre frequencies U and V along x and y-axes respectively) %described by the following equation %% % 1 -1 x ^ y ^ %%% Gi(x,y) = ---------- * exp ([----{(----) 2+(----) 2}])*Mi(x,y,f); % 2*pi*sx*sy 2 sx sy %%% i =1,2 %%% M1(x,y,f) = cos[2*pi*f*sqrt(x^2+y^2)]; %%% M2(x,y,f) = cos[2*pi*f*(x*cos(theta) + y*sin(theta)]; %% Describtion : %% I : Input image %% Sx & Sy : Variances along x and y-axes respectively %% f : The frequency of the sinusoidal function %% theta : The orientation of Gabor filter %% G1 & G2 : The output filters as described above %% gabout1 & gabout2 : The output filtered images %% Author : Ahmad poursaberi e-mail : a.poursaberi@ece.ut.ac.ir %% Faulty of Engineering, Electrical&Computer Department,Tehran %% University,Iran,June 2004 function [G1,G2,gabout1,gabout2] = gaborfilter(I,Sx,Sy,f,theta); if isa(I,'double')~=1 I = double(I); end for x = -fix(Sx):fix(Sx) for y = -fix(Sy):fix(Sy) M1 = cos(2*pi*f*sqrt(x^2+y^2)); M2 = cos(2*pi*f*(x*cos(theta)+y*sin(theta))); G1(fix(Sx)+x+1,fix(Sy)+y+1) = (1/(2*pi*Sx*Sy)) * exp(-.5*((x/Sx)^2+(y/Sy)^2))*M1; G2(fix(Sx)+x+1,fix(Sy)+y+1) = (1/(2*pi*Sx*Sy)) * exp(-.5*((x/Sx)^2+(y/Sy)^2))*M2; end end Imgabout1 = conv2(I,double(imag(G1)),'same'); Regabout1 = conv2(I,double(real(G1)),'same'); Imgabout2 = conv2(I,double(imag(G2)),'same'); Regabout2 = conv2(I,double(real(G2)),'same'); gabout1 = sqrt(Imgabout1.*Imgabout1 + Regabout1.*Regabout1); gabout2 = sqrt(Imgabout2.*Imgabout2 + Regabout2.*Regabout2);