Gabor小波变换代码 Gabor小波变换代码 Gabor小波变换代码

% GABORFILTER Bi-dimensional Gabor filter with DC component compensation. % [G,GABOUT]=GABORFILTER(I,S,F,W,P) filters the input image I with the 2D % Gabor filter G described by the parameters S, F, W and P to create the % output filtered image GABOUT. % This version of the 2D Gabor filter is basically a bi-dimensional % Gaussian function centered at origin (0,0) with variance S modulated by % a complex sinusoid with polar frequency (F,W) and phase P described by % the following equation: % % G(x,y,S,F,W,P)=k*Gaussian(x,y,S)*(Sinusoid(x,y,F,W,P)-DC(F,S,P)), % where: % Gaussian(x,y,S)=exp(-pi*S^2*(x^2+y^2)) % Sinusoid(x,y,F,W,P)=exp(j*(2*pi*F*(x*cos(W)+y*sin(W))+P))) % DC(F,S,P)=exp(-pi*(F/S)^2+j*P) % % PS: The term DC(F,S,P) compensates the inherent DC component produced % by the Gaussian envelop as shown by Movellan in [1]. % % Tips: % 1) To get the real part and the imaginary part of the complex % filter output use real(gabout) and imag(gabout), respectively; % % 2) To get the magnitude and the phase of the complex filter output % use abs(gabout) and angle(gabout), respectively. % Author: Stiven Schwanz Dias e-mail: stivendias@gmail.com % Cognition Science Group, Informatic Department, % University of Esp�rito Santo, Brazil, January 2007. % % References: % [1] Movellan, J. R. - Tutorial on Gabor Filters. Tech. rep., 2002. function [G,GABOUT]=gaborfilter(I,S,F,W,P); if isa(I,'double')~=1 I=double(I); end size=fix(1.5/S); % exp(-1.5^2*pi) < 0.1% %k=2*pi*S^2; %F=S^2/sqrt(2*pi); k=1; for x=-size:size for y=-size:size G(size+x+1,size+y+1)=k*exp(-pi*S^2*(x*x+y*y))*... (exp(j*(2*pi*F*(x*cos(W)+y*sin(W))+P))-exp(-pi*(F/S)^2+j*P)); end end GABOUT=conv2(I,double(G),'same');