Using commercial photo camera's RAW-based images in optical-digital correlator for pattern recognition

In optical-digital correlators for pattern recognition, linear registration of correlation signals is significant for both of recognition reliability and possible input image restoration. This usually achieves with scientific graduated technical cameras, but most of commercial digital cameras now have an option of RAW data output. With appropriate software and parameters of processing, it is possible to get linearized image data from photo camera's RAW file. Application of such photo cameras makes optical-digital systems cheaper, more flexible and brings along their wider propagation. For linear registration of correlation signals, open-source Dave Coffins's RAW converter DCRAW was used in this work. Data from photo camera were linearized by DCRAW converter in "totally RAW documental mode" with 16-bit output. Experimental results of comparison between linearized and non-linearized correlation signals and digitally restored input scene images are presented. It is shown, that applied linearization allows to increase linear dynamic range for used Canon EOS 400D camera more that 3 times.