boundingRectAsync function
BoundingRect calculates the up-right bounding rectangle of a point set.
For further details, please see: https:///docs.opencv.org/3.3.0/d3/dc0/group__imgproc__shape.html#gacb413ddce8e48ff3ca61ed7cf626a366
Implementation
Future<Rect> boundingRectAsync(VecPoint points) async =>
cvRunAsync((callback) => cffi.BoundingRect_Async(points.ref, callback), rectCompleter);