Display and enhancement of infrared images

Over the last several years, the author and his colleagues have studied the display and enhancement of IR imagery. A survey of the main results and conclusions is presented in the paper. The IR images which support the work are obtained as 12-bit digitized single frames from PtSi staring cameras designed in a laboratory. In mapping such `raw´ image data to 8-bit values for display, one frequently encounters image signals whose dynamic range is well in excess of typical monitor/eye capabilities. A useful division is to group algorithms for such mappings into two broad types: global monotonic mappings, in which the radiometric trend in the raw recorded image is retained in the display; and mappings which drop this constraint. The former set is viewed as the baseline display of an IR image, which ideally is a temperature mapping of the scene, while the latter group is often needed to provide local contrast enhancement. These two types of algorithm are described