harris角点检测算子

				ori_im2=rgb2gray(imread('2.bmp'));    
				ori_im2=imresize(ori_im2',0.50,'bicubic');    
				
				fx = [5 0 -5;8 0 -8;5 0 -5];          % % la gaucienne，ver axe x
				Ix = filter2(fx,ori_im2);              % la convolution vers axe x
				fy = [5 8 5;0 0 0;-5 -8 -5];          % la gaucienne，ver axe y
				Iy = filter2(fy,ori_im2);              % la convolution vers axe y
				Ix2 = Ix.^2;
				Iy2 = Iy.^2;
				Ixy = Ix.*Iy;
				clear Ix;
				clear Iy;
				
				h= fspecial('gaussian',[3 3],2);      % générer une fonction gaussienne，sigma=2
				
				Ix2 = filter2(h,Ix2);
				Iy2 = filter2(h,Iy2);
				Ixy = filter2(h,Ixy);
				
				height = size(ori_im2,1);
				width = size(ori_im2,2);
				result = zeros(height,width);         % enregistrer la position du coin
				
				R = zeros(height,width);
				
				K=0.04
				Rmax = 0;                              % chercher la valeur maximale de R
				for i = 1:height
				    for j = 1:width
				        M = [Ix2(i,j) Ixy(i,j);Ixy(i,j) Iy2(i,j)];         
				        R(i,j) = det(M)-K*(trace(M))^2;                     % % calcule R
				        if R(i,j) > Rmax
				           Rmax = R(i,j);
				        end;
				    end;
				end;
				
				cnt = 0;
				for i = 2:height-1
				    for j = 2:width-1
				        % réduire des valuers minimales ，la taille de fenetre 3*3
				        if R(i,j) > 0.01*Rmax && R(i,j) > R(i-1,j-1) && R(i,j) > R(i-1,j) && R(i,j) > R(i-1,j+1) && R(i,j) > R(i,j-1) && R(i,j) > R(i,j+1) && R(i,j) > R(i+1,j-1) && R(i,j) > R(i+1,j) && R(i,j) > R(i+1,j+1)
				            result(i,j) = 1;
				            cnt = cnt+1;
				        end;
				    end;
				end;
				
				[posr2, posc2] = find(result == 1);
				cnt                                      % compter des coins
				figure
				imshow(ori_im2);
				hold on;
				plot(posc2,posr2,'r+');