1. A scene based nonuniformity correction method for use with a scanning infrared sensor, said method comprising the steps of: providing a video input signal derived from an image; processing the video input signal such that a vector representing offset correction terms is formed, wherein each element in the vector represents a correction term for a particular detector of the scanning infrared sensor and wherein the vector is initially set to zero; separating the image into vertically oriented regions, each region comprising a plurality of channels; computing an average of each channel within a region forming a set of region vectors, such that there is one region vector for each region; globally high-pass filtering each region vector wherein edges larger than predefined threshold are detected and marked separating each region vector into sub-regions demarcated by the edges; locally high-pass filtering each sub-region computing the offset correction terms for each vertical region vector from said high-pass filtered sub-regions; and applying the offset correction terms to the video signal.