simpletrack.cpp

This example demonstrates how to track points in a sequence of images using polyora.

/*  This file is part of Polyora, a multi-target tracking library.
    Copyright (C) 2010 Julien Pilet

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with this program. If not, see <http://www.gnu.org/licenses/>.

    To contact the author of this program, please send an e-mail to:
    julien.pilet(at)calodox.org
*/
#include <iostream>
#include <highgui.h>

#include <polyora/polyora.h>

using namespace std;

int main(int argc, char *argv[]) {

        if (argc<2) {
                cerr << "usage: " << argv[0] << " <image> [<image> ...]\n";
                return -1;
        }

        // load an image to obtain the width/height
        IplImage *first = cvLoadImage(argv[1]);
        if (first==0) {
                cerr << argv[1] << ": can't load image\n";
                return -1;
        }
        int width = first->width;
        int height = first->height;
        cvReleaseImage(&first);

        kpt_tracker tracker(width, height, 3, 10);

        // Optionally loads quantization tree and track clusters
        tracker.load_from_db("visual.db");

        for (int i=1; i<argc; i++) {
                // the 0 is here to tell opencv to convert the image to grey level,
                // because process_frame accepts only single channel images
                IplImage *im = cvLoadImage(argv[i], 0);
                if (!im) {
                        cerr << argv[i] << ": can't load image\n";
                        continue;
                }

                // process_frame will detect points and take care of calling cvReleaseImage(im) when required.
                tracker.process_frame(im);

                // get a pointer to the most recent frame
                pyr_frame *frame= (pyr_frame *)tracker.get_nth_frame(0);

                // iterate over all the frame's keypoints
                for (tracks::keypoint_frame_iterator it(frame->points.begin()); !it.end(); ++it) {
                        pyr_keypoint *k = (pyr_keypoint *) it.elem();

                        cout << "(" << k->u << "," << k->v << ")";
                }
                cout << endl;

                // free tracks lost two frames ago
                tracker.remove_unmatched_tracks(tracker.get_nth_frame(2));
        }

        return 0;
}