#include "opencv2/video/tracking.hpp" #include "opencv2/imgproc.hpp" #include "opencv2/videoio.hpp" #include "opencv2/highgui.hpp" #include <iostream> using namespace cv; using namespace std; static void help() { cout << "\nThis program demonstrates dense optical flow algorithm by Gunnar Farneback\n" "Mainly the function: calcOpticalFlowFarneback()\n" "Call:\n" "./fback\n" "This reads from video camera 0\n" << endl; } static void drawOptFlowMap(const Mat& flow, Mat& cflowmap, int step, double, const Scalar& color) { for(int y = 0; y < cflowmap.rows; y += step) for(int x = 0; x < cflowmap.cols; x += step) { const Point2f& fxy = flow.at<Point2f>(y, x); line(cflowmap, Point(x,y), Point(cvRound(x+fxy.x), cvRound(y+fxy.y)), color); circle(cflowmap, Point(x,y), 2, color, -1); } } int main(int argc, char** argv) { cv::CommandLineParser parser(argc, argv, "{help h||}"); if (parser.has("help")) { help(); return 0; } VideoCapture cap(0); help(); if( !cap.isOpened() ) return -1; Mat flow, cflow, frame; UMat gray, prevgray, uflow; namedWindow("flow", 1); for(;;) { cap >> frame; cvtColor(frame, gray, COLOR_BGR2GRAY); if( !prevgray.empty() ) { calcOpticalFlowFarneback(prevgray, gray, uflow, 0.5, 3, 15, 3, 5, 1.2, 0); cvtColor(prevgray, cflow, COLOR_GRAY2BGR); uflow.copyTo(flow); drawOptFlowMap(flow, cflow, 16, 1.5, Scalar(0, 255, 0)); imshow("flow", cflow); } if(waitKey(30)>=0) break; std::swap(prevgray, gray); } return 0; }