R. S. Starikov

Linear Phase Coefficient Composite Filter (LPCСF) are one of the most perspective types of invariant correlation filters (CF). This СF type application provides the correlation peak invariance for different geometrical distortions of input edged image. Well-known optical-electronic diffractive correlator schemes have considerable advantages in comparison with purely electronic vehicle in a number of cases that is why they are strongly of development and application interest. In case of optical-electronic correlator СF is carried out as a synthesized diffractive element - static or dynamically formed by space light modulator. Since light modulator is the real СF carrier the holographic medium can only provide limited dynamic range of modulator and it is important to consider this fact when the СF is carried out. Here are the results of holographic medium dynamic range limitation effect on characteristics of linear phase coefficient filter in Vander Lught correlator scheme. Different versions of LPCСF were synthesized and corresponding amplitude diffractive elements were computed. The characteristic modification analysis of obtained filters under the gray scale number limitation in hologram pixels was carried out. False images, similar in power to the true and similar in liner sizes and form to the true images were used to estimate the interclass selectivity of scheme. Satisfactory characteristics of correlation peaks are kept even for hologram with pixels contained less then eight gray scales. There should be not lesser then sixteen numbers of gray scales in hologram to maintain the correlation characteristics of filter

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