title: Rotation- and scale-invariant feature extraction by a diffractive optical inner-product transform.
abstract: A diffractive optical element that is capable of extracting rotation- and scale-invariant features from input images is presented. The diffractive optical element performs an inner product between the input image and a set of basis functions. This set of basis functions is derived from that used in the Fourier-Mellin transform. Simulated results from scaled and rotated versions of two input images are presented.
authors.forename: F S
authors.initials: FS
authors.lastname: Roux