Composite Filter Trees and Image Recognition via Binary Search

摘要

Construction rules for building composite binary phase-only filters (CBPOFs)designed for use at the nodes of a binary tree have been developed using unweighted superposition algorithms. This paper describes the use of this method to build a four-target, rotation-invariant CBPOF bank on which binary tree searches can be performed. Each of the four trees in this filter bank consists of 256 simple filters (BPOFS) and 254 composites. Sequential search of the 256 simple image recognition system utilizing the filter bank has been developed, assembled, and evaluated by simulation and experiment. The empirical results obtained using a hybrid optical correlator with computer-controlled magneto-optic spatial light modulators (MOSLMs) at the input and filter planes are presented.