Impact of detector-element active-area shape and fill factor on super-resolution

In many undersampled imaging systems, spatial integration from the individual detect elements is the dominant component of the system point spread function (PS Conventional focal plane arrays (FPAs) utilize square detector elements with a nea 100% fill factor, where fill factor is defined as the fraction of the detector eleme area that is active in light detection. A large fill factor is generally considered to desirable because more photons are collected for a given pitch, and this leads to a high signal-to-noise-ratio (SNR). However, the large active area works against super-resoluti (SR) image restoration by acting as an additional low pass filter in the overall PSF wh modeled on the SR sampling grid. A high fill factor also tends to increase blurring fro pixel cross-talk. In this paper, we study the impact of FPA detector-element shape a fill factor on SR. A detailed modulation transfer function analysis is provided along wi a number of experimental results with both simulated data and real data acquired wi a midwave infrared (MWIR) imaging system. We demonstrate the potential advantage low fill factor detector elements when combined with SR image restoration. Our resul suggest that low fill factor circular detector elements may be the best choice. New vid results are presented using robust adaptive Wiener filter SR processing applied to da from a commercial MWIR imaging system with both high and low detector element factors. or F). rly nt be er on en m nd th th of ts eo ta fill