如何仅将图像上的白色区域视为轮廓

Question

I have a binary image, from which I need to consider only the white regions as contours but it also takes black region which is surrounded by white part as contour. I don't want to use contour area, can we ignore the black regions while finding contours? Here is the binary image and the orange color marked is also considered as contour, so do not want the black region surrounded with white to be considered as contour.

Contour image is:

My contouring code:

//contouring
    vector<vector<Point> > contours;
    findContours(img, contours, RETR_LIST, CHAIN_APPROX_SIMPLE);
    vector<vector<Point> > contours_poly(contours.size());
    vector<Rect> boundRect(contours.size());
    vector<Point2f>centers(contours.size());
    vector<float>radius(contours.size());
    for (size_t i = 0; i < contours.size(); i++)
    {
        approxPolyDP(contours[i], contours_poly[i], 3, true);
        boundRect[i] = boundingRect(contours_poly[i]);
        minEnclosingCircle(contours_poly[i], centers[i], radius[i]);
    }
    Mat drawing = Mat::zeros(img.size(), CV_8UC3);
    
    for (size_t i = 0; i < contours.size(); i++)
    {
        Scalar color = Scalar(rng.uniform(0, 256), rng.uniform(0, 256), rng.uniform(0, 256));
        
        drawContours(drawing, contours_poly, (int)i, color);
}

Answer 1

Your code snippets do not compose a minimal reproducible example ( https://stackoverflow.com/help/minimal-reproducible-example ). Therefore I could not run it for testing.

However - you might be able to achieve what you want by "playing" with the 2 last parameters of cv::findContours .

From opencv documentation of cv::findContours :

    mode    Contour retrieval mode, see [RetrievalModes][1]

    method  Contour approximation method, see [ContourApproximationModes][1]