Abstract
An amplitude-modulated phase-only filter1, referred to here as an amplitude-modulated inverse filter (AMIF). The AMIF function is given by (1) where D and A can be constants or functions of both u and v, |R(u,v)| is the amplitude of Fourier spectrum of the reference function r(x,y), and (u,v) is the phase factor of R(u,v). The constraint D |R(u,v)| min+A guarantees that the gain of an AMIF based correlator is less than or equal to unity for all frequency values. When A < |R(u,v)|, AMIF is found to have a good correlation discrimination (CD) just as that of an IF and when A > |R(u,v) |, it is found to have a good optical efficiency (OE) as that of a phase-only filter (POF). By choosing values for A between the limits A < |R(u,v)| and A > |R(u,v)|, all the transition states between a POF and IF can be obtained. POF delivers nearly 100% OE and IF delivers the best CD. The AMIF allows for a trade-off between OE and CD and is shown to be very flexible to meet the pattern recognition applications. Our results show that AMIF has a better CD performance than that of a POF in the absence and presence of noise.
© 1990 Optical Society of America
PDF ArticleMore Like This
Song H. Zheng, Mohammad A. Karim, and Ming L. Gao
ThMM23 OSA Annual Meeting (FIO) 1991
S. H. Zheng, Mohammad A. Karim, and Abdul Ahad S. Awwal
TUZ1 OSA Annual Meeting (FIO) 1989
Abdul Ahad S. Awwal, Mohammad A. Karim, and Syeda R. Jahan
TUZ3 OSA Annual Meeting (FIO) 1989