Patent ID: 8526780

Claim:
A method for recording or modifying and reproducing thermal images of a scene or of an object, comprising: generating a pixel-based thermal image frame by infrared optics and a pixel-based detector unit or retrieving a pixel-based thermal image frame from an external source, generating a dark image for non-uniformity correction to eliminate non-uniformities arising from the detector or from sources of disturbance in an optical beam path, correcting the pixel-based thermal image frame by weighting individual pixel values with a nonlinear characteristic line generated and stored in advance to generate a corrected output thermal image, and providing the corrected output thermal image to a display unit or to an interface for external equipment, wherein the nonlinear characteristic line is calculated according to the formula: S out = S max 1 + 1 k - ⅇ - k · ( 1 + S i ⁢ ⁢ n S max · k - ⅇ - k · S i ⁢ ⁢ n S max ) , where: S min is a minimum signal intensity, S max is a maximum signal intensity, S in is an input signal intensity, S out is an output signal intensity, and k is a compression parameter between 0.1 and 10.