Utilizing Optical Defocusing and Computational Imaging for Laser Intensity Reduction at CCD Focal Planes

Sensor protection against agile-frequency lasers is a critical Army Technology Objective (ATO). We propose simple defocusing of existing sensor optics as a layer within the optical limiting (OL) stack. This requires no additional optical components, and promotes compatibility with other OL stack elements. The challenge resides in computing the inverse filtering operation to recover the in-focus image for real-time display. Our Phase I results demonstrated a debluring algorithm capable of performing at realistic signal to noise ratios against acquired imagery using actual standard COTS lenses. We showed the algorithm works well in fixed point arithmetic and thus is amenable to implementation on field programmable gate array (FPGA) hardware, a critical aspect of real-time implementation. In Phase 2, we will demonstrate and deliver a real-time CD (Computational Deblurring) prototype system, comprised of a purposely defocused COTS CCD video camera interfaced to a COTS host PC and integrated CD Processor. The COTS CD Processor will run a customized CD algorithm that deblurs 3 megapixel defocused color imagery at 30 fps. Our team member, using technology spun out of the University of Notre Dame which effectively confronts the memory bandwidth bottleneck in embedded processors, is uniquely qualified to produce the minimal-resources CD Processor.