Otman's profile - activity

Hello everyone i am having a problem with camshiftdemo.cpp sample can be found in opencv\sources\samples\cpp

it works but after a while of running it crashes cv::Exception at memory location

at this line 159

if (trackWindow.area() <= 1)

can someone help me fixing it .

#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;

Mat image;

bool backprojMode = false;
bool selectObject = false;
int trackObject = 0;
bool showHist = true;
Point origin;
Rect selection;
int vmin = 10, vmax = 256, smin = 30;

static void onMouse(int event, int x, int y, int, void*)
{
    if (selectObject)
    {
        selection.x = MIN(x, origin.x);
        selection.y = MIN(y, origin.y);
        selection.width = std::abs(x - origin.x);
        selection.height = std::abs(y - origin.y);

        selection &= Rect(0, 0, image.cols, image.rows);
    }

    switch (event)
    {
    case CV_EVENT_LBUTTONDOWN:
        origin = Point(x, y);
        selection = Rect(x, y, 0, 0);
        selectObject = true;
        break;
    case CV_EVENT_LBUTTONUP:
        selectObject = false;
        if (selection.width > 0 && selection.height > 0)
            trackObject = -1;
        break;
    }
}

static void help()
{
    cout << "\nThis is a demo that shows mean-shift based tracking\n"
        "You select a color objects such as your face and it tracks it.\n"
        "This reads from video camera (0 by default, or the camera number the user enters\n"
        "Usage: \n"
        "   ./camshiftdemo [camera number]\n";

    cout << "\n\nHot keys: \n"
        "\tESC - quit the program\n"
        "\tc - stop the tracking\n"
        "\tb - switch to/from backprojection view\n"
        "\th - show/hide object histogram\n"
        "\tp - pause video\n"
        "To initialize tracking, select the object with mouse\n";
}

const char* keys =
{
    "{1|  | 0 | camera number}"
};

int main(int argc, const char** argv)
{
    help();

    VideoCapture cap;
    Rect trackWindow;
    int hsize = 16;
    float hranges[] = { 0, 180 };
    const float* phranges = hranges;
    CommandLineParser parser(argc, argv, keys);
    int camNum = parser.get<int>("1");

    cap.open(camNum);

    if (!cap.isOpened())
    {
        help();
        cout << "***Could not initialize capturing...***\n";
        cout << "Current parameter's value: \n";
        parser.printParams();
        return -1;
    }

    namedWindow("Histogram", 0);
    namedWindow("CamShift Demo", 0);
    setMouseCallback("CamShift Demo", onMouse, 0);
    createTrackbar("Vmin", "CamShift Demo", &vmin, 256, 0);
    createTrackbar("Vmax", "CamShift Demo", &vmax, 256, 0);
    createTrackbar("Smin", "CamShift Demo", &smin, 256, 0);

    Mat frame, hsv, hue, mask, hist, histimg = Mat::zeros(200, 320, CV_8UC3), backproj;
    bool paused = false;

    for (;;)
    {
        if (!paused)
        {
            cap >> frame;

            if (frame.empty())
                break;
        }

        frame.copyTo(image);

        if (!paused)
        {
            cvtColor(image, hsv, COLOR_BGR2HSV);

            if (trackObject)
            {
                int _vmin = vmin, _vmax = vmax;

                inRange(hsv, Scalar(0, smin, MIN(_vmin, _vmax)),
                    Scalar(180, 256, MAX(_vmin, _vmax)), mask);
                int ch[] = { 0, 0 };
                hue.create(hsv.size(), hsv.depth());
                mixChannels(&hsv, 1, &hue, 1, ch, 1);

                if (trackObject < 0)
                {
                    Mat roi(hue, selection), maskroi(mask, selection);
                    calcHist(&roi, 1, 0, maskroi, hist, 1, &hsize, &phranges);
                    normalize(hist, hist, 0, 255, CV_MINMAX);

                    trackWindow = selection;
                    trackObject = 1;

                    histimg = Scalar::all(0);
                    int binW = histimg.cols / hsize;
                    Mat buf(1, hsize, CV_8UC3);
                    for (int i = 0; i < hsize; i++)
                        buf.at<Vec3b>(i) = Vec3b(saturate_cast<uchar>(i*180. / hsize), 255, 255 ...