opencv/cxcore.go
func GetCols(arr Arr, submat *Mat, start_col, end_col int) *Mat {
	mat_new := C.cvGetCols(
		unsafe.Pointer(arr),
		(*C.CvMat)(submat),
		C.int(start_col),
		C.int(end_col),
	)
	return (*Mat)(mat_new)
}
func GetCols(arr Arr, submat *Mat, start_col, end_col int) *Mat {
	mat_new := C.cvGetCols(
		unsafe.Pointer(arr),
		(*C.CvMat)(submat),
		C.int(start_col),
		C.int(end_col),
	)
	return (*Mat)(mat_new)
}
/* Selects column span of the input array: arr(:,start_col:end_col)
   (end_col is not included into the span) */