The two -dimensional joint histogram or co-occurrence matrix of two images provides a convenient vehicle for the design of scene matching algorithms which effectively incorporate information about expected variations between reference and sensor -derived data. Thus, specified histogram pairings, orderings, or degrees of clustering can be rewarded as appropriate by the matching algorithm. In particular, intensity-independent algorithms can be designed which are invariant under an arbitrary permutation of labels in one or both images to be matched and, as a result, they are insensitive to contrast reversals. Such algorithms can utilize synthetic reference maps constructed by assigning arbitrary labels to designated regions, thus eliminating the need for material identification and sensor response prediction. Two different types of intensityindependent algorithms are described and their performance is compared to that of conventional matching algorithms using a set of infrared images acquired over a 24 -hour period.