We consider an integral transform called a circular Radon transform (CRT) and being a generalization of the Radon transform for the integration performed along a definite circumference, instead of a straight line. The circumference radius is the transform parameter. The expressions of the CRT for some specific functions are derived. Relationships for deriving the pattern of shifted or scaled object are deduced. An optical scheme for the CRT implementation is given. Possibilities of applying CRT for digits recognition verified.
Victor V. Kotlyar,
Alexey A. Kovalev,
"Circular average transform for image processing", Proc. SPIE 5485, Optical Technologies for Communications, (18 May 2004); doi: 10.1117/12.564902; https://doi.org/10.1117/12.564902