  In this paper, we present theoretical details and the underlying architecture
of a hybrid optoelectronic correlator that correlates images using Spatial
Light Modulators (SLM), detector arrays and Field Programmable Gate Array
(FPGA). The proposed architecture bypasses the need for nonlinear materials
such as photorefractive polymer films by using detectors instead, and the phase
information is yet conserved by the interference of plane waves with the
images. However, the output of such a Hybrid Opto-electronic Correlator (HOC)
has four terms: two convolution signals and two cross-correlation signals. By
implementing a phase stabilization and scanning circuit, the convolution terms
can be eliminated, so that the behavior of an HOC becomes essentially identical
to that of a conventional holographic correlator (CHC). To achieve the ultimate
speed of such a correlator, we also propose an opto-electronic chip which would
perform all the electrical processes in a parallel manner. The HOC architecture
along with the phase stabilization technique would thus be as good as a CHC,
capable of high speed image recognition in a translation invariant manner.
