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#include "opencv2/video/tracking.hpp" #include "opencv2/imgproc/imgproc.hpp" #include "opencv2/highgui/highgui.hpp" #include <iostream> #include <ctype.h> using namespace cv; using namespace std; static void help() { // print a welcome message, and the OpenCV version cout << "\nThis is a demo of Lukas-Kanade optical flow lkdemo(),\n" "Using OpenCV version " << CV_VERSION << endl; cout << "\nIt uses camera by default, but you can provide a path to video as an argument.\n"; cout << "\nHot keys: \n" "\tESC - quit the program\n" "\tr - auto-initialize tracking\n" "\tc - delete all the points\n" "\tn - switch the \"night\" mode on/off\n" "To add/remove a feature point click it\n" << endl; } Point2f point; bool addRemovePt = false; static void onMouse( int event, int x, int y, int /*flags*/, void* /*param*/ ) { if( event == CV_EVENT_LBUTTONDOWN ) { point = Point2f((float)x, (float)y); addRemovePt = true; } } int main( int argc, char** argv ) { help(); VideoCapture cap; TermCriteria termcrit(CV_TERMCRIT_ITER|CV_TERMCRIT_EPS, 20, 0.03); Size subPixWinSize(10,10), winSize(31,31); const int MAX_COUNT = 500; bool needToInit = false; bool nightMode = false; if( argc == 1 || (argc == 2 && strlen(argv[1]) == 1 && isdigit(argv[1][0]))) cap.open(argc == 2 ? argv[1][0] - '0' : 0); else if( argc == 2 ) cap.open(argv[1]); if( !cap.isOpened() ) { cout << "Could not initialize capturing...\n"; return 0; } namedWindow( "LK Demo", 1 ); setMouseCallback( "LK Demo", onMouse, 0 ); Mat gray, prevGray, image; vector<Point2f> points[2]; for(;;) { Mat frame; cap >> frame; if( frame.empty() ) break; frame.copyTo(image); cvtColor(image, gray, COLOR_BGR2GRAY); if( nightMode ) image = Scalar::all(0); if( needToInit ) { // automatic initialization goodFeaturesToTrack(gray, points[1], MAX_COUNT, 0.01, 10, Mat(), 3, 0, 0.04); cornerSubPix(gray, points[1], subPixWinSize, Size(-1,-1), termcrit); addRemovePt = false; } else if( !points[0].empty() ) { vector<uchar> status; vector<float> err; if(prevGray.empty()) gray.copyTo(prevGray); calcOpticalFlowPyrLK(prevGray, gray, points[0], points[1], status, err, winSize, 3, termcrit, 0, 0.001); size_t i, k; for( i = k = 0; i < points[1].size(); i++ ) { if( addRemovePt ) { if( norm(point - points[1][i]) <= 5 ) { addRemovePt = false; continue; } } if( !status[i] ) continue; points[1][k++] = points[1][i]; circle( image, points[1][i], 3, Scalar(0,255,0), -1, 8); } points[1].resize(k); } if( addRemovePt && points[1].size() < (size_t)MAX_COUNT ) { vector<Point2f> tmp; tmp.push_back(point); cornerSubPix( gray, tmp, winSize, cvSize(-1,-1), termcrit); points[1].push_back(tmp[0]); addRemovePt = false; } needToInit = false; imshow("LK Demo", image); char c = (char)waitKey(10); if( c == 27 ) break; switch( c ) { case 'r': needToInit = true; break; case 'c': points[0].clear(); points[1].clear(); break; case 'n': nightMode = !nightMode; break; } std::swap(points[1], points[0]); cv::swap(prevGray, gray); } return 0; }详见博主:https://blog.csdn.net/liangchunjiang/article/details/79869830
