1 clear all;
 2 close all;
 3 clc;
 4 
 5 
 6 %%
 7 %以下只是做一个带直线的图像而已
 8 r=300;           
 9 jiaodu=30;      %更改这个值测试，90度270度时不管用
10 jiaodu1=mod(jiaodu,360);     
11 flag=0;
12 
13 if jiaodu1>=0 && jiaodu1<90
14     jiaodu1=jiaodu1;
15     flag=1;
16 end
17 
18 if jiaodu1>=90 && jiaodu1<180
19     jiaodu1=180-jiaodu1;
20     flag=2;
21 end
22 
23 if jiaodu1>=180 && jiaodu1<270
24     jiaodu1=jiaodu1-180;
25     flag=3;
26 end
27 
28 if jiaodu1>=270 && jiaodu1<360
29     jiaodu1=360-jiaodu1;
30     flag=4;
31 end
32 
33 H=floor(r*sin(jiaodu1*pi/180));
34 W=floor(r*cos(jiaodu1*pi/180));
35 
36 if mod(H,2)==0
37     H=H+1;
38 end
39 
40 if mod(W,2)==0
41     W=W+1;
42 end
43 
44 w=zeros(H,W);
45 if jiaodu1 ~= 90 && jiaodu1 ~= 270
46     for i=1:H
47         for j=1:W
48             tmp=floor(j*tan(jiaodu1*pi/180));
49             if tmp+1==i
50                 w(i,j)=r;
51             end
52         end
53     end
54 else
55     for i=1:H
56         w(i,1)=r;
57     end
58 end
59 if flag==1 || flag==3       %如果角度在1,3象限，卷积矩阵上下翻转
60     w=flipud(w);        
61 end
62 %%
63 %下面是真正的霍夫变换
64 img=mat2gray(w);      %处理这个图像
65 [m n]=size(img);
66 imshow(img);
67 
68 data=zeros(314,2*(m+n));
69 for i=1:m                       %将图像二维空间的一个点映射到p=x*cos(theta)+y*sin(theta)方程对应的参数空间的一条曲线
70     for j=1:n
71         if img(i,j)==1            
72             for theta=0.01:0.01:3.14
73                 data(round(theta*100),round(i*sin(theta)+j*cos(theta)+m+n))= ...
74                 data(round(theta*100),round(i*sin(theta)+j*cos(theta)+m+n))+1;
75             end        
76         end
77     end
78 end
79 
80 theta=0;
81 ma=0;
82 for i=1:314                 %寻找曲线相交最多的那个点，即找最大值
83     for j=1:2*(m+n)
84         if data(i,j)>ma
85             ma=data(i,j);
86             theta=i/100;
87             rou=j-m-n;
88         end
89     end
90 end
91 figure;imshow(data)     %形象的显示参数空间曲线
92 
93 sr_k=tan(jiaodu*pi/180)     %设置的斜率
94 re_k=cos(theta)/sin(theta)  %求得的斜率