An analysis of fusion algorithms for LWIR and visual images

Abstract

This paper presents a comparison of methods to fuse pre-registered colour visual and long wave infra-red images to create a new image containing both visual and thermal cues. Three methods of creating the artificially coloured fused images are presented. These three methods along with the raw visual and LWIR imagery are then evaluated using the Analytical Hierarchy Process for three different scenarios using a set of 32 observers. The scenarios entail bright, dim and dark conditions which directly affect the amount of visual information available. Both the standard method and a novel voting methodology are used to evaluate the results, the latter providing similar ranking but better discrimination between the voter’s preferences. The results show that fused images are preferred for non-dark conditions with the thermal based hue offset algorithm being preferred.