該程式是opencv中文論壇的牛人貢獻的，感謝他的工作。

1. // Sum of Absolute Difference(SAD) 
2. #include <iostream>
3. #include <stdio.h>
4. #include <stdlib.h>
5. #include <cv.h>
6. #include <cxcore.h>
7. #include <highgui.h>
8. #include <math.h>
9. #include <ctime>
10. usingnamespace
     std;  
11. template<class T> class Image  
12. {  
13. private:  
14.     IplImage* imgp;  
15. public:  
16.     Image(IplImage* img=0){imgp=img;}  
17.     ~Image(){imgp=0;}  
18.     voidoperator=(IplImage* img){imgp=img;}  
19.     inline T* operator[](constint rowIndx)  
20.     {  
21.         return((T*)(imgp->imageData+rowIndx*imgp->widthStep));  
22.     }  
23. };  
24. typedef struct
25. {  
26.     unsigned char b,g,r;  
27. }RgbPixel;  
28. typedef struct
29. {  
30.     float b,g,r;  
31. }RgbPixelFloat;  
32. typedef Image<RgbPixel> RgbImage;  
33. typedef Image<RgbPixelFloat> RgbImageFloat;  
34. typedef Image<unsigned char> BwImage;  
35. typedef Image<float> BwImageFloat;  
36. //display an image in a new window with title to be given.
37. void displayImageNewWindow(char* title,CvArr* img)  
38. {  
39.     cvNamedWindow(title, CV_WINDOW_AUTOSIZE );  
40.     cvShowImage(title,img);  
41. }  
42. int getMaxMin(double value[],int valueSize, int maxmin)  
43. {  
44.     int pos=0;  
45.     int i=0;  
46.     double max1=-1;//?-999999;
47.     double min1=999999;  
48.     if (maxmin==1)  
49.     {  
50.         //find max
51.         for (i=0;i<valueSize;i++)  
52.         {  
53.             //find the index with the max value;
54.             if (value[i]>max1)  
55.             {  
56.                 pos=i;  
57.                 max1=value[i];  
58.             }  
59.         }  
60.     }  
61.     if (maxmin==0)  
62.     {  
63.         //find min
64.         for (i=0;i<valueSize;i++)  
65.         {  
66.             //find the index with the minimum value;
67.             if (value[i]<min1)  
68.             {  
69.                 pos=i;  
70.                 min1=value[i];  
71.             }  
72.         }           
73.     }  
74.     return pos;  
75. }  
76. IplImage* generateDisparityImage(IplImage* greyLeftImg32,IplImage* greyRightImg32,int windowSize,int DSR)  
77. {  
78.     int offset=floor((double)windowSize/2);  
79.     int height=greyLeftImg32->height;  
80.     int width=greyLeftImg32->width;  
81.     double* localSAD=newdouble[DSR];  
82.     int x=0, y=0,d=0,m=0;  
83.     int N=windowSize;              
84.     IplImage* winImg=cvCreateImage(cvSize(N,N),32,1);//mySubImage(greyLeftImg32,cvRect(0,0,N,N));
85.     IplImage* disparity=cvCreateImage(cvSize(width,height),8,1);//or IPL_DEPTH_8U
86.     BwImage imgA(disparity);  
87.     for (y=0;y<height;y++)  
88.     {  
89.       for (x=0;x<width;x++)  
90.       {  
91.          imgA[y][x]=0;  
92.       }  
93.     }  
94.     CvScalar sum;  
95.     //CvScalar s2;
96.     for (y=0;y<height-N;y++)  
97.     {   
98.         //height-N
99.         for (x=0;x<width-N;x++)  
100.         {  
101.             //width-N
102.             cvSetImageROI(greyLeftImg32, cvRect(x,y,N,N));  
103.             d=0;           
104.             //initialise localSAD
105.             for (m=0;m<DSR;m++)  
106.             {  
107.                 localSAD[m]=0;  
108.             }  
109.             //start matching
110.              do{  
111.                 if (x-d>=0)  
112.                 {  
113.                     cvSetImageROI(greyRightImg32, cvRect(x-d,y,N,N));  
114.                 }  
115.                 else
116.                 {  
117.                 break;  
118.                 }  
119.                 cvAbsDiff(greyLeftImg32,greyRightImg32,winImg);//absolute difference
120.                 sum=cvSum(winImg);//sum
121.                 localSAD[d]=sum.val[0];//0 means single channel
122.                 cvResetImageROI(greyRightImg32);  
123.                 d++;  
124.             }while(d<=DSR);  
125.             //to find the best d and store
126.             imgA[y+offset][x+offset]=getMaxMin(localSAD,DSR,0)*16; //0 means return minimum index
127.             cvResetImageROI(greyLeftImg32);  
128.         }//x
129.         if (y%10==0)  
130.             cout<<"row="<<y<<" of "<<height<<endl;   
131.     }//y
132.     cvReleaseImage(&winImg);  
133.     //cvReleaseImage(&rightWinImg);
134.     return disparity;  
135. }  
136. int main (int argc, char * const argv[])   
137. {  
138.     cout << "Sum of Absolute Difference(SAD) Strereo Vision"<<endl;   
139.     //**********image input*********************// 
140.     char* filename1="L.jpg";//im2_cone.png
141.     IplImage* greyLeftImg= cvLoadImage(filename1,0);  
142.     char* filename2="R.jpg";  
143.     IplImage* greyRightImg= cvLoadImage(filename2,0);  
144.     if (greyLeftImg==NULL){cout << "No valid image input."<<endl; return 1;}  
145.     if (greyRightImg==NULL){cout << "No valid image input."<<endl; return 1;}  
146.     int width=greyLeftImg->width;  
147.     int height=greyLeftImg->height;   
148.     /****************8U to 32F**********************/
149.     IplImage* greyLeftImg32=cvCreateImage(cvSize(width,height),32,1);//IPL_DEPTH_32F
150.     IplImage* greyRightImg32=cvCreateImage(cvSize(width,height),32,1);  
151.     cvConvertScale(greyLeftImg, greyLeftImg32, 1/255.);  
152.     cvConvertScale(greyRightImg, greyRightImg32, 1/255.);//1/255. equals to 1/255.0
153.     //-------------obtain disparity image----------------
154.     time_t tstart, tend;  
155.     tstart = time(0);  
156.     int windowSize=13,DSR=20;//Disparity Search Range
157.     IplImage* disparity32=generateDisparityImage(greyLeftImg32,greyRightImg32,windowSize,DSR);  
158.     tend = time(0);  
159.     cout << "It took "<< difftime(tend, tstart) <<" second(s)."<< endl;  
160.     displayImageNewWindow("Dispairty Image",disparity32);  
161.     displayImageNewWindow("Left Image",greyLeftImg32);  
162.     displayImageNewWindow("Right Image",greyRightImg32);  
163.     //cvSaveImage("D:/OpenCV_stuff/SampleImages/disparitySAD.jpg",disparity32);
164.     //********destroy window************/
165.     cvWaitKey(0);  
166.     cvReleaseImage(&greyLeftImg32);  
167.     cvReleaseImage(&greyRightImg32);  
168.     cvReleaseImage(&greyLeftImg);  
169.     cvReleaseImage(&greyRightImg);  
170.     cvReleaseImage(&disparity32);  
171.     cvDestroyWindow("Left Image");  
172.     cvDestroyWindow("Right Image");  
173.     cvDestroyWindow("Dispairty Image");  
174.     return 0;  
175. }