Developing a reliable face recognition system has been an open problem. Infrared (IR) imagery appears to be a good alternative as it is independent of external illumination. However

IR images are also affected by a series of factors ranging from imaging

ambient condition to physiological and psychological conditions. The variations of temperature in IR images have analogous effects of illumination in visual images. In this paper

a method based on Stefan-Boltzmann Law has been applied to convert the facial temperature data intomore consistent radiation energy data. The experiments conducted illustrate that the radiation energy data are less sensitive to ambient temperature if the human bodies are in steady state

and significantly out performs temperature data in terms of recognition rate.