I need to detect the object's contour of an image. For that purpose, I'm using the OpenCV library's function findContours. I'm using OpenCV 3.0 (x86) on Windows 10 (x64) compiled by me with the contrib modules.

The problem

The problem is that, when I try to use this function, the application crashes. The error is not an exception or an assertion failure, I can only see a window saying to me that the application has crashed:

What I have tested

I have checked that the image I'm passing to findContours is a binary image:

I have checked the type of the image, which is 0, the same as CV_8U value.

I have even checked the histogram, and there are only pixels with values 0 and 1.

I have also searched for examples from OpenCV tutorials and forums, and I have tried to do exactly the same than in the example, and the program crashes again.

The code

Here is the code that I'm executing:

// This is the main function:
int test_findContours(const std::string &path){
    Mat img = imread(path, IMREAD_GRAYSCALE);
    if (!img.data){
        cout << "ERROR" << endl;
        return -1;
    }
    Mat mask;
    getRemBackgroundMask(img, mask);

    vector< vector<Point> > contours;

    // Here the program crashes:
    findContours(mask, contours, CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE);
    return 0;
}

// Get the mask to remove the background
void getRemBackgroundMask(const Mat &img, Mat &mask) {
    threshold(img, mask, 70, 1, THRESH_BINARY_INV);

    Mat kernel = getStructuringElement(MORPH_RECT, Size(3, 3));
    openning(mask, mask, kernel);
}

void openning(const Mat &binary, Mat &result, const Mat &kernel){
    erode(binary, result, kernel);
    dilate(binary, result, kernel);
}