1. A system comprising: a memory adapted to receive a visible spectrum image of a scene from a visible spectrum imager and a plurality of infrared images of the scene from an infrared imager; and a processor configured to communicate with the memory, wherein the processor is configured to: generate a blurred infrared image from at least one of the plurality of infrared images; determine, for each row of the blurred infrared image, a corresponding row fixed pattern noise (FPN) correction term; determine, for each column of the blurred infrared image, a corresponding column FPN correction term; apply the row and column FPN correction terms to the blurred infrared image to provide a row and column FPN corrected blurred infrared image; determine a plurality of non-uniformity correction (NUC) terms based, at least in part, on the row and column FPN corrected blurred infrared image; apply the NUC terms to one of the plurality of the infrared images to remove noise from the one of the plurality of the infrared images to provide a corrected infrared image; receive control parameters; derive high spatial frequency content from at least one of the visible spectrum image and the corrected infrared image; and generate a combined image comprising relative contributions of at least the high spatial frequency content, wherein the relative contributions are determined in real-time by a user adjusting the control parameters.