Types of signals	Asymmetric Symmetric Symmetric about x or y
Scalar	$O (\frac{M N \cdot \log_{2} (M N)}{2})$ $O (\frac{M N \cdot \log_{2} (M N)}{8})$ $O (\frac{M N \cdot \log_{2} (M N)}{4})$
Complex	$O (M N \cdot \log_{2} (M N))$ $O (\frac{M N \cdot \log_{2} (M N)}{4})$ $O (\frac{M N \cdot \log_{2} (M N)}{2})$
Vector	$O (\frac{3 M N \cdot \log_{2} (M N)}{2})$ $O (\frac{3 M N \cdot \log_{2} (M N)}{8})$ $O (\frac{3 M N \cdot \log_{2} (M N)}{4})$
Quaternion	$O (2 M N \cdot \log_{2} (M N))$ $O (\frac{M N \cdot \log_{2} (M N)}{2})$ $O (M N \cdot \log_{2} (M N))$