Radiometric image restoration and calibration for thermal and other video images

The authors describe the experimental evaluation of an image processing algorithm which provides radiometric restoration and calibration. Using this technique, the response of a modified TICM II thermal imager to a test field is related, pixel by pixel, to the corresponding responses to two calibrated reference fields having different radiances. Systematic spatial variations of responsivity arising from defects in image formation, scanning, detection and electronic processing are removed to the limits of precision imposed by noise, stability and roundoff. The algorithm can also be applied to other fields of quantitative imaging.