PERFORMANCE OF A PHASE-TRANSFORMED INPUT JOINT TRANSFORM CORRELATOR

Conventionally a detected image is represented by an intensity array o wing to the square-law nature of most detectors. However, this does no t mean that we have to restrict ourselves to using intensity images fo r the correlation process. Transforming intensity images into phase im ages before correlation, which can be easily realized by a phase-modul ation spatial light modulator, offers an alternative approach for high -performance pattern recognition, A phase-transformed input joint tran sform correlator is investigated in detail in terms of pattern discrim inability, detection efficiency, and noise robustness. We show that th e phase-transformed joint transform correlator has higher pattern disc riminability and detection efficiency than the conventional joint tran sform correlator, and it also offers a better trade-off between the pa ttern discriminability and noise tolerance. A proof-of-concept experim ent is also provided. (C) 1996 Optical Society of America.