A TRANSFORMATION WITH INVARIANCE UNDER CYCLIC PERMUTATION FOR APPLICATIONS IN PATTERN RECOGNITION

The paper describes a transformation that can be used to characterize patterns independent of their position. Examples of the application of the transform for the machine recognition of letters are discussed. The program succeeded in a recognition rate of 80-100% for letters having different position, distortions, inclination, rotation up to 15° and size variation up to 1:3 relative to a reference set of 10 letters. Results with a program for the autonomous learning of new varieties of a pattern (using a learning matrix as an adaptive classifier) are given. When executed on a digital computer, this transform is 10-100 times faster than the fast Fourier transform (depending on the number of sampling points). © 1969 Academic Press, Inc.