Optical Mellin transforms using computer generated holograms

The scale invariant correlation possible with Mellin transforms has made this operation extremely important in pattern recognition for image and signal processing. This operation is realized by a geometrical transformation $\text{?(x, y) → ?(}\text{exp}\text{ξ,}\text{exp}\text{η)}$ followed by an optical Fourier transform. The use of computer generated hologram masks to effect the ξ = ln x, η = ln y transformation are discussed.