sortIdxAsync function
SortIdx sorts each row or each column of a matrix. Instead of reordering the elements themselves, it stores the indices of sorted elements in the output array
For further details, please see: https://docs.opencv.org/master/d2/de8/group__core__array.html#gadf35157cbf97f3cb85a545380e383506
Implementation
Future<Mat> sortIdxAsync(InputArray src, int flags) async =>
cvRunAsync((callback) => cffi.core_SortIdx_Async(src.ref, flags, callback), matCompleter);