Phase-only Synthetic Discriminant Function Research Articles

Adaptive phase-input joint transform correlator

An adaptive phase-input joint transform correlator for pattern recognition is presented. The input of the system is two phase-only images: input scene and reference. The reference image is generated with a new iterative algorithm using phase-only synthetic discriminant functions. The algorithm takes into account calibration lookup tables of all optoelectronics elements used in optodigital experiments. The designed adaptive phase-input joint transform correlator is able to reliably detect a target and its distorted versions embedded into a cluttered background. Computer simulations are provided and compared with those of various existing joint transform correlators in terms of discrimination capability, tolerance to input additive noise, and to small geometric image distortions. Experimental optodigital results are also provided and discussed.

Properties of computer-generated, phase-only synthetic discriminant filters

The paper presents the experimental properties of the phase-only synthetic discriminant functions (SDF) filter when trained for invariance to in-plane rotation. Digital simulations and optical implementations by computer-generated holography are presented with results showing rejection of objects with a mean intensity six times that of the training class.

Computer-generated and phase-only synthetic discriminant function filters

The laboratory realization of smart matched spatial filters (specifically snythetic discriminant functions) is considered and studied via computer simulation. The realization of these distortion-invariant correlator functions by computer-generated hologram and other methods is considered. Multiclass filters are addressed in this work. Phase-only filters and filters with a quantized number of amplitude and phase levels are considered. Phase-only filters are found to perform well for some imagery, but filters with some amplitude response are preferable. We also considered the number of phase and magnitude levels required and found four levels of each to be adequate.