countNonZeroAsync function
CountNonZero counts non-zero array elements.
For further details, please see: https://docs.opencv.org/master/d2/de8/group__core__array.html#gaa4b89393263bb4d604e0fe5986723914
Implementation
Future<int> countNonZeroAsync(Mat src) async =>
cvRunAsync((callback) => cffi.core_CountNonZero_Async(src.ref, callback), intCompleter);