extractChannel function
ExtractChannel extracts a single channel from src (coi is 0-based index).
For further details, please see: https://docs.opencv.org/master/d2/de8/group__core__array.html#gacc6158574aa1f0281878c955bcf35642
Implementation
Mat extractChannel(InputArray src, int coi, {OutputArray? dst}) {
dst ??= Mat.empty();
cvRun(() => cffi.Mat_ExtractChannel(src.ref, dst!.ref, coi));
return dst;
}