OPTICAL-PROCESSING OF SPECKLE IMAGES WITH BACTERIORHODOPSIN FOR PATTERN-RECOGNITION

Logarithmic processing of images with multiplicative noise characteris tics can be utilized to transform an image into one with an additive n oise distribution. This simplifies subsequent image processing steps f or applications such as image restoration or correlation for pattern r ecognition. One particularly common form of multiplicative noise is sp eckle, for which the logarithmic operation not only produces additive noise, but also makes it of constant variance (signal-independent). I examine the optical transmission properties of some bacteriorhodopsin films here and find them well suited to implement such a pointwise log arithmic transformation optically in a parallel fashion. I present exp erimental results of the optical conversion of speckle images into tra nsformed images with additive, signal-independent noise statistics usi ng the real-time photochromic properties of bacteriorhodopsin. I provi de an example of improved correlation performance in terms of correlat ion peak signal-to-noise for such a transformed speckle image.