Template matching on video, not yet using scale or orientation

template_matching.cpp

#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
#include <vector>

using namespace cv;
using namespace std;

// Based on:
// http://docs.opencv.org/2.4/doc/tutorials/imgproc/histograms/template_matching/template_matching.html

int main( int argc, char* argv[])
{
	Mat templ;
	templ = imread(argv[1], IMREAD_COLOR);

	if (templ.empty())
	{
		cout << "Could not open or find the image" << std::endl;
		return 0;
	}

	VideoCapture cap(0);
	if (!cap.isOpened())
	{
		cout << "Cannot open the video cam" << endl;
		return -1;
	}

	Mat frame_prev;

	// read a new frame from video
	bool bSuccess = cap.read(frame_prev);
	//if not successful, break loop
	if (!bSuccess)
	{
		cout << "Cannot read a frame from video stream" << endl;
	}

	// create windows for display
	namedWindow("MyVideo0", WINDOW_AUTOSIZE);
	namedWindow("TemplateMatch", WINDOW_AUTOSIZE);
	namedWindow("Template", WINDOW_AUTOSIZE);

    // create template matching matrix and helper variables
    double minVal, maxVal;
    Point minLoc, maxLoc, matchLoc;

    int cols = frame_prev.cols - templ.cols + 1;
    int rows = frame_prev.rows - templ.rows + 1;
    cout << cols << " " << rows << endl;
    Mat result( rows, cols, CV_32FC1 );

	while (1)
	{
		// read a new frame from video
		Mat frame;
		bSuccess = cap.read(frame);
		//if not successful, break loop
		if (!bSuccess)
		{
			cout << "Cannot read a frame from video stream" << endl;
			break;
		}

        // template match
        matchTemplate( frame, templ, result, CV_TM_SQDIFF );
        normalize( result, result, 0, 1, NORM_MINMAX, -1, Mat() );

        minMaxLoc( result, &minVal, &maxVal, &minLoc, &maxLoc, Mat() );
        matchLoc = minLoc;

		rectangle( frame, matchLoc,
					Point( matchLoc.x + templ.cols,
                           matchLoc.y + templ.rows ),
					Scalar::all(0), 2, 8, 0 );
		rectangle( result, matchLoc,
                    Point( matchLoc.x + templ.cols,
                           matchLoc.y + templ.rows ),
                    Scalar::all(0), 2, 8, 0 );

		imshow("MyVideo0", frame);
		//imshow("TemplateMatch", result);
		imshow("Template", templ);

        // update previous frame
		frame_prev = frame;

		// Wait for 'esc' key press for 30ms.
        // If 'esc' key is pressed, break loop
		if (waitKey(30) == 27)
		{
			cout << "esc key is pressed by user" << endl;
			break;
		}

	}
	cap.release();
	return 0;
}