Mat.fromRange constructor
Implementation
factory Mat.fromRange(Mat mat, int rowStart, int rowEnd, {int colStart = 0, int? colEnd}) {
final p = calloc<cvg.Mat>();
colEnd ??= mat.cols;
cvRun(() => ccore.cv_Mat_create_12(mat.ref, rowStart, rowEnd, colStart, colEnd!, p, ffi.nullptr));
return Mat._(p);
}