opencv/samples/cpp/mask_tmpl.cpp

#include "opencv2/imgproc.hpp"
#include "opencv2/highgui.hpp"

#include <cctype>
#include <iostream>
#include <iterator>
#include <stdio.h>

using namespace std;
using namespace cv;

static void help()
{
    cout << "\nThis program demonstrates template match with mask.\n"
            "Usage:\n"
            "./mask_tmpl <image_name> <template_name> <mask_name>, Default is ../data/lena_tmpl.jpg\n"
            << endl;
}

int main( int argc, const char** argv )
{
    const char* filename = argc == 4 ? argv[1] : "../data/lena_tmpl.jpg";
    const char* tmplname = argc == 4 ? argv[2] : "../data/tmpl.png";
    const char* maskname = argc == 4 ? argv[3] : "../data/mask.png";

    Mat img = imread(filename);
    Mat tmpl = imread(tmplname);
    Mat mask = imread(maskname);
    Mat res;

    if(img.empty())
    {
        help();
        cout << "can not open " << filename << endl;
        return -1;
    }

    if(tmpl.empty())
    {
        help();
        cout << "can not open " << tmplname << endl;
        return -1;
    }

    if(mask.empty())
    {
        help();
        cout << "can not open " << maskname << endl;
        return -1;
    }

    //int method = CV_TM_SQDIFF;
    int method = CV_TM_CCORR_NORMED;
    matchTemplate(img, tmpl, res, method, mask);

    double minVal, maxVal;
    Point minLoc, maxLoc;
    Rect rect;
    minMaxLoc(res, &minVal, &maxVal, &minLoc, &maxLoc);

    if(method == CV_TM_SQDIFF || method == CV_TM_SQDIFF_NORMED)
        rect = Rect(minLoc, tmpl.size());
    else
        rect = Rect(maxLoc, tmpl.size());

    rectangle(img, rect, Scalar(0, 255, 0), 2);

    imshow("detected template", img);
    waitKey();

    return 0;
}