Patent ID: 7899271

Claim:
A method of calibration of non-uniformity compensation (NUC) terms for a pixilated imager, comprising: a) providing a test scene having a target in a background at different intensity levels; b) scanning the test scene across the imager field of view (FOV) to generate a sequence of target images in which the test scene is repeated in an overlapping pattern at different target placements across the imager FOV so that each fully compensated imager pixel images at least one target intensity level and at least one background intensity level; c) registering the sequence of target images to the target to create a sequence of registered target images; d) filtering the registered target images to form a registered average image; e) backward mapping the registered average image to the different target placements in the imager FOV to create an estimated target image for each target image; for each fully compensated imager pixel, performing an N th order correlation of the target image intensity levels to the estimated target image level intensity levels for different target and background test scene pixels imaged by that imager pixel to estimate at least gain non-uniformity compensation (NUC) terms for the imager such that fully compensated imager pixels provide approximately the same response to the same scene intensity level; and g) storing at least gain NUC terms as calibration weights for the imager.