%見課本403，hough變換的全過程，涉及到hough,houghpeaks,houghlines三個函數的調用
close all;clear;clc;
a=imread('d:\test.bmp');
a=a(:,:,1);
f=edge(a,'prewitt');
[H,theta,rho]=hough(f,1);
imshow(theta,rho,H,[],'notruesize'),axis on, axis normal
[r,c]=houghpeaks(H,18);
hold on;
plot(theta(c),rho(r),'linestyle','none','marker','s','color','w');
 lines=houghlines(f,theta,rho,r,c);
 figure;imshow(f),hold on
 for k=1:length(lines)
xy=[lines(k).point1;lines(k).point2]
plot(xy(:,2),xy(:,1),'LineWidth',4,'Color',[.6,.6,.6]);
end