1 %2017-05-12   学习LBP特征  
 2 
 3  clc;
 4  clear;
 5 
 6 %读图操作
 7 img=imread(‘船 (403).bmp‘);
 8 [m,n]=size(img);
 9 figure(1);
10 imshow(img,[]);
11 title(‘原图‘);
12 %%
13 %求原始的LBP特征
14 img_LBP=zeros(m,n);
15 for i=2:m-1
16    for j=2:n-1 
17        
18        code=zeros(1,8);    %行向量
19        code(1)=img(i-1,j-1)>img(i,j);
20        code(2)=img(i-1,j)>img(i,j);
21        code(3)=img(i-1,j+1)>img(i,j);
22        code(4)=img(i,j+1)>img(i,j);
23        code(5)=img(i+1,j+1)>img(i,j);
24        code(6)=img(i+1,j)>img(i,j);
25        code(7)=img(i+1,j-1)>img(i,j);
26        code(8)=img(i,j-1)>img(i,j);
27        for p=1:8
28            img_LBP(i,j)=img_LBP(i,j)+code(p)*2^(8-p);     %从左上角开始，顺时针编码
29        end
30        
31    end
32 end
33 
34 figure(2);
35 imshow(img_LBP,[]);
36 title(‘original LBP‘);
37 %%
38 %求旋转不变LBP
39 img_LBP_ri=zeros(m,n);
40 for i=2:m-1
41    for j=2:n-1 
42        
43        code=zeros(1,8);    %行向量，原始LBP特征编码
44        code(1)=img(i-1,j-1)>img(i,j);
45        code(2)=img(i-1,j)>img(i,j);
46        code(3)=img(i-1,j+1)>img(i,j);
47        code(4)=img(i,j+1)>img(i,j);
48        code(5)=img(i+1,j+1)>img(i,j);
49        code(6)=img(i+1,j)>img(i,j);
50        code(7)=img(i+1,j-1)>img(i,j);
51        code(8)=img(i,j-1)>img(i,j);
52        for p=1:8
53            img_LBP_ri(i,j)=img_LBP_ri(i,j)+code(p)*2^(8-p);     %从左上角开始，顺时针编码
54        end
55        
56        %循环左移,移动k位相当于把开头的k个数放到最右边
57        for k=1:7
58            code=[code(k+1:end) code(1:k)];    %移位之后的二进制编码，右移表达式 code=[code(end-k+1:end) code(1:end-k)]
59            temp=0;
60            for p=1:8
61                temp=temp+code(p)*2^(8-p);
62            end
63            if temp<img_LBP_ri(i,j)    %取旋转之后的最小值
64                img_LBP_ri(i,j)=temp;
65            end
66        end
67        
68    end
69 end
70 
71 figure(3);
72 imshow(img_LBP_ri,[]);
73 title(‘rotate invariant LBP‘);