An invertible rapid transform

Abstract

The Rapid Transform (RT) is a fast transform which is useful for shift invariant signal classification and recognition. We modify the RT in such a manner that during the forward transformation a code matrix is generated which records the “phase information” of the input pattern. With this code matrix a one-to-one mapping of the transformed pattern to the original pattern with normalized (learned) position can be achieved. Numerical experiments show that nearly all information is stored in the code matrix, not in the RT. The Invertible Rapid Transform (IRT) can be used in shift invariant signal filtering and transform coding of image sequences.