opencv 尋找亞像素角點



opencv 尋找亞像素角點

void CImageProcess::FindCorner()
{
 const int MAX_CORNERS = 1000 ; 
 CvPoint2D32f* corners = new CvPoint2D32f[ MAX_CORNERS ]; 
 int corner_count = MAX_CORNERS; 
 int half_win_size = 3 ;//the window size will be 3+1+3=7
 int iteration = 20; 
 double epislon = 1;
 double quality_level = 0.1; //OR 0.01 
 double min_distance = 5; 

 IplImage* image = GetBuffer_cv();
 IplImage* img_gray = cvCreateImage(cvGetSize( image ),IPL_DEPTH_8U, 1) ; 
 IplImage* eig_image = cvCreateImage(cvGetSize( image ),IPL_DEPTH_32F, 1); 
 IplImage* temp_image = cvCloneImage( eig_image ) ; 
 cvGoodFeaturesToTrack( 
         image, 
         eig_image,          
         temp_image, 
         corners, 
         &corner_count, 
         quality_level, 
         min_distance 
     ); 

  cvFindCornerSubPix( 
   image, 
   corners, 
   corner_count, 
   cvSize(half_win_size,half_win_size), 
   cvSize(-1,-1),//no ignoring the neighbours of the center corner 
   cvTermCriteria(CV_TERMCRIT_ITER|CV_TERMCRIT_EPS,iteration,epislon) 
   ); 

 //draw subpix corners on "img_copy" 
 IplImage* img_copy = cvCreateImage(cvSize(image->width,image->height),8,3);
 //cvSplit(src, dst1, dst2, dst3, NULL);
 cvMerge(image, NULL, NULL, NULL, img_copy);

 cvLine(  
  img_copy, 
  cvPoint(0,0) , 
  cvPoint(img_copy->width,img_copy->height),
  CV_RGB(255,0,0), 
  5 
  );
 for (int i=0;i<corner_count;i++)
 { 
  float xxx=corners[i].x;
  float yyy = corners[i].y;
  cvLine(  
   img_copy, 
   cvPoint(corners[i].x,corners[i].y) , 
   cvPoint(corners[i].x,corners[i].y), 
   CV_RGB(255,0,0), 
   5 
   ); 
 }
 CString str;
 CvScalar mean;
 mean = cvAvg(image);
 str.Format("test\\%.0fjiaodian.bmp",mean.val[0]);
 cvSaveImage(str,img_copy);
}

cvFindCornerSubPix是角點尋找函數

其中cvTermCriteria解釋如下：

1. CvTermCriteria  
2. 迭代算法的終止準則  
3. #define CV_TERMCRIT_ITER    1  
4. #define CV_TERMCRIT_NUMBER  CV_TERMCRIT_ITER  
5. #define CV_TERMCRIT_EPS     2  
6.   
7. typedef struct CvTermCriteria  
8.  {  
9.   int    type;  /* CV_TERMCRIT_ITER 和CV_TERMCRIT_EPS二值之一，或者二者的組合 */  
10.   int    max_iter; /* 最大迭代次數 */  
11.   double epsilon; /* 結果的精確性 */  
12.  }  
13.  CvTermCriteria;  
14. /* 構造函數 */  
15. inline  CvTermCriteria  cvTermCriteria( int type, int max_iter, double epsilon );  
16. /* 在滿足max_iter和epsilon的條件下檢查終止準則並將其轉換使得type=CV_TERMCRIT_ITER+CV_TERMCRIT_EPS */  
17. CvTermCriteria cvCheckTermCriteria( CvTermCriteria criteria,  
18.                                     double default_eps,  
19.                                     int default_max_iters );