Numerical evaluation of the efficiency of camouflage systems in the thermal infrared

This paper proposes a new method for evaluating the efficiency of countermeasures in the thermal infrared. Thermal camouflage materials are developed to attenuate the incident infrared energy and to change the emissivity factor. These effects have a great influence on the detectability of the object in its background. To give a numerical value to the efficiency of the considered camouflage, a software environment has been developed which delineates the target from its background and makes a comparison using features selected from those which are known to be important in human vision. To find the edge of the target, a semi-automatic approach is introduced based on a breadth first search in a directed graph. The edge finding problem is translated in a search for a cyclic path through the graph, using an initial estimate. This method gives a very reliable contour and makes it possible to give a realistic evaluation of the blending of the object in its background.