We describe a new fast, shift-invariant transform, the modified rapid transform (MRT). The MRT combines the well-known rapid transform with preprocessing steps. Computer simulations show that for 1-D binary patterns the MRT with a sufficient number of preprocessing steps may perform shift-invariant one-to-one mapping. The modification is also efficient for 2-D patterns. The MRT can be usefully applied as a preprocessing step in automatic inspection and pattern recognition, where shift invariance, uniqueness, and low computing time is required. As an example, the use of MRT in optical character recognition is discussed.
© 1989 Optical Society of America
Ming Fang and Gerd Häusler, "Modified rapid transform," Appl. Opt. 28, 1257-1262 (1989)