Optimization of a binary filter by direct binary search algorithm for rotation-invariant JTC

An optimum training process using a direct binary search algorithm for synthesising a spatial domain binary filter to implement in the joint transform correlator (JTC) architecture is presented. The major advantage of the proposed filter are rotation invariance, higher discriminability for similar targets, and convenience for optical implementation in the JTC using a Ferroelectric over silicon SLM as a binary phase modulator. Results of the invariant filter are presented for classical JTC, DC free JTC using phase shifting technique, and for the binarised JTC by applying edge-enhancement and mean thresholding at the JPS. Testing so far, shows that binary filter is able to distinguish between target and anti-target images for all these cases.

[1]  D. Casasent,et al.  Minimum average correlation energy filters. , 1987, Applied optics.

[2]  Francis T. S. Yu,et al.  A real-time programmable joint transform correlator , 1984 .

[3]  Timothy D. Wilkinson,et al.  The binary phase-only 1/f joint transform correlator , 1998 .

[4]  Bahram Javidi,et al.  Synthetic Discriminant Function-Based Nonlinear Optical Correlator , 1989, Photonics West - Lasers and Applications in Science and Engineering.

[5]  Y Ichioka,et al.  Computer-generated multiple-object discriminant correlation filters: design by simulated annealing. , 1995, Applied optics.

[6]  Kehar Singh,et al.  Discrimination-sensitive rotation-invariant joint-transform correlator using gradient preprocessing and circular harmonic components , 1998 .

[7]  Timothy D. Wilkinson,et al.  Ferroelectric liquid crystal on silicon spatial light modulator designed for high yield and low cost fabrication: The fast bitplane SLM , 1998 .

[8]  Alfredo Dubra,et al.  Nonlinear joint transform correlator using one-dimensional Fourier transformation , 1998 .

[9]  Jan P. Allebach,et al.  Multilevel screen design using direct binary search , 2002, IS&T/SPIE Electronic Imaging.

[10]  C C Guest,et al.  Simulated annealing algorithm for binary phase only filters in pattern classification. , 1990, Applied optics.

[11]  F T Yu,et al.  Implementation of a non-zero-order joint-transform correlator by use of phase-shifting techniques. , 1997, Applied optics.

[12]  D Casasent,et al.  Unified synthetic discriminant function computational formulation. , 1984, Applied optics.

[13]  Partha P. Banerjee,et al.  Rotation-Invariant Synthetic Discriminant Function Filter for Pattern Recognition , 2000 .