func (m *Mat) Reshape(channels, rows int) *Mat {
	total := m.Cols() * m.Rows()
	n := CreateMat(rows, total/rows, m.Type())
	C.cvReshape(unsafe.Pointer(m), (*C.CvMat)(n), C.int(channels), C.int(rows))
	return n
}
func (m *Mat) Reshape(channels, rows int) *Mat {
	total := m.Cols() * m.Rows()
	n := CreateMat(rows, total/rows, m.Type())
	C.cvReshape(unsafe.Pointer(m), (*C.CvMat)(n), C.int(channels), C.int(rows))
	return n
}
/*
Reshape changes shape of the matrix without copying data. A value of `0` means
that channels or rows remain unchanged.
*/