#include "highgui/highgui.hpp"  
#include "opencv2/nonfree/nonfree.hpp" 
#include "opencv2/video/tracking.hpp" 
#include <iostream> 
 
using namespace cv; 
using namespace std; 
 
Mat image1,image2; 
vector<Point2f> point1,point2,pointCopy; 
vector<uchar> status; 
vector<float> err; 
 
int main(int argc,char *argv[])  
{  
 VideoCapture video(argv[1]); 
 double fps=video.get(CV_CAP_PROP_FPS); //獲取視頻幀率 
 double pauseTime=1000/fps; //兩幅畫面中間間隔  
 video>>image1; 
 Mat image1Gray,image2Gray; 
 cvtColor(image1,image1Gray,CV_RGB2GRAY); 
 goodFeaturesToTrack(image1Gray,point1,100,0.01,10,Mat()); 
 pointCopy=point1; 
 for(int i=0;i<point1.size();i++) //繪制特征點位 
 {   
  circle(image1,point1[i],1,Scalar(0,0,255),2);   
 }  
 namedWindow("角點特征光流",0); 
 imshow("角點特征光流",image1); 
 while(true) 
 { 
  video>>image2; 
  if(!image2.data||waitKey(pauseTime)==27) //圖像為空或Esc鍵按下退出       
  { 
   break; 
  } 
  cvtColor(image2,image2Gray,CV_RGB2GRAY); 
  calcOpticalFlowPyrLK(image1Gray,image2Gray,point1,point2,status,err,Size(20,20),3); //LK金字塔  
  for(int i=0;i<point2.size();i++) 
  { 
   circle(image2,point2[i],1,Scalar(0,0,255),2); 
   line(image2,pointCopy[i],point2[i],Scalar(255,0,0),2); 
  }   
  imshow("角點特征光流",image2); 
  swap(point1,point2); 
  image1Gray=image2Gray.clone(); 
 }  
 return 0;  
}