I am trying to use the following code to extract blob center coordinates in an image. Problem is the marked line gives me an exception every time and when commented out runs without exceptions. Iv tried different permutations to shed further light but I am still stuck:
threshold(imgUndistorted, matBinImg, 15, 220, THRESH_BINARY); imshow("Binary Image:", matBinImg); Ptr<SimpleBlobDetector> detector = SimpleBlobDetector::create(params); detector->detect(matBinImg, binaryKeypoints); drawKeypoints(matBinImg, binaryKeypoints, img_binwith_keypoints, Scalar(0, 0, 255), DrawMatchesFlags::DRAW_RICH_KEYPOINTS); (problem lines below) **x_img = binaryKeypoints.pt.x;** **y_img = binaryKeypoints.pt.y;** Imshow("Test Window", img_binwith_keypoints); waitKey(1); I've also tried: Point2f p = binaryKeypoints[i].pt; float x = binaryKeypoints[i].pt.x; float y = binaryKeypoints[i].pt.y;
Exception thrown: read access violation.
binaryKeypoints._Mypair._Myval2._Myfirst was nullptr.