close all;

clear all;

I=imread('test.tif');

[posX,posY]=harris(I);

figure;imshow(I);

hold on; plot(posX, posY, 'g*');

function [posX,posY]=harris(I)

%Harris角点检测

%I:输入图像

%posX:角点X坐标

%posY:角点Y坐标

I=double(I);

[m,n]=size(I);

hx=[-,,;-,,;-,,];

Ix=imfilter(I,hx,'replicate','same');%X方向差分图像

Iy=imfilter(I,hx','replicate','same');%Y方向差分图像

Ix2=Ix.^;

Iy2=Iy.^;

Ixy=Ix.*Iy;

h=fspecial('gaussian',,);

Ix2=imfilter(Ix2,h,'replicate','same');%高斯滤波

Iy2=imfilter(Iy2,h,'replicate','same');

Ixy=imfilter(Ixy,h,'replicate','same');

R=zeros(m,n);

k=0.04;%建议值(0.04--0.06)

for i=:m

    for j=:n

       R(i,j)=(Ix2(i,j)*Iy2(i,j)-Ixy(i,j)*Ixy(i,j))-k*((Ix2(i,j)+Iy2(i,j))^);%角点响应值

    end

end

T=0.1*max(R(:));% 阈值，可控制返回的角点个数

result=zeros(m,n);

%非极大值抑制（*3窗口中大于阈值T的局部极大值点被认为是角点）

for i=:m-

    for j=:n-

        tmp=R(i-:i+,j-:j+);

        tmp(,)=;

        if(R(i,j)>T&&R(i,j)>max(tmp(:)))

            result(i,j)=;

        end

    end

end

[posY,posX]=find(result);