convexityDefectsAsync function
ConvexityDefects finds the convexity defects of a contour.
For further details, please see: https:///docs.opencv.org/master/d3/dc0/group__imgproc__shape.html#gada4437098113fd8683c932e0567f47ba
Implementation
Future<Mat> convexityDefectsAsync(VecPoint contour, Mat hull, {Mat? convexityDefects}) async {
  convexityDefects ??= Mat.empty();
  return cvRunAsync0(
    (callback) => cimgproc.cv_convexityDefects(contour.ref, hull.ref, convexityDefects!.ref, callback),
    (c) {
      return c.complete(convexityDefects);
    },
  );
}