matlab实现gabor filter (5)

gabor filter源代码：

 

%%%%%%%VERSION 2%%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     x' ^     y'  ^             %%% G(x,y,theta,f) =  exp ([----{(----) 2+(----) 2}])*cos(2*pi*f*x');%                             2    sx'       sy'%%% x' = x*cos(theta)+y*sin(theta);%%% y' = y*cos(theta)-x*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%% G : The output filter as described above%% gabout : The output filtered image%%  Author : Ahmad poursaberi  e-mail : [e-mail]%%          Faulty of Engineering, Electrical&Computer Department,Tehran%%          University,Iran,June 2004function [G,gabout] = gaborfilter1(I,Sx,Sy,f,theta)if isa(I,'double')~=1     I = double(I);endfor x = -fix(Sx):fix(Sx)    for y = -fix(Sy):fix(Sy)        xPrime = x * cos(theta) + y * sin(theta);        yPrime = y * cos(theta) - x * sin(theta);        G(fix(Sx)+x+1,fix(Sy)+y+1) = exp(-.5*((xPrime/Sx)^2+(yPrime/Sy)^2))*cos(2*pi*f*xPrime);    endendImgabout = conv2(I,double(imag(G)),'same');Regabout = conv2(I,double(real(G)),'same');gabout = sqrt(Imgabout.*Imgabout + Regabout.*Regabout);

 

调用代码：

 

close all;clear all;clc;% 读入图像image=imread('C:\Users\watkins\Pictures\cartoon.jpg');grayImage=rgb2gray(image);grayImage=im2double(grayImage);% 显示读入图像imshow(grayImage);sx=32;sy=32;theta=[0 pi/4 2*pi/4 3*pi/4 4*pi/4 5*pi/4 6*pi/4 7*pi/4];gamma=1;psi=0;sigma=6; % 也可以为12lambda=[5 6 7 8 9];V=[4 5 6 7 8];U=[0 pi/4 2*pi/4 3*pi/4 4*pi/4 5*pi/4 6*pi/4 7*pi];%U=[1 2 3 4 5 6 7 8];% Creating 40 Gabor FiltersG = cell(5,8);for i = 1:5    for j = 1:8        G{i,j}=zeros(65,65);    endendfor i = 1:5    for j = 1:8        f=1/lambda(i);        %[T,gabout] = gaborfilter(grayImage,sx,sy,U(j),V(i));        %G{i,j} = T;        G{i,j} = gaborfilter1(grayImage,sx,sy,f,theta(j));    endend% Showing Gabor Filtersfigure;for s = 1:5    for j = 1:8                subplot(5,8,(s-1)*8+j);                %imshow(real(G{s,j})/2-0.5,[]);        imshow(real(G{s,j}),[]);    endend

 

显示的滤波器组图片：

 

可以明显看到波长和方向的变化