Camaeleon--camouflage assessment by evaluation of local energy, spatialfrequency, and orientation

Camaeleon is a computer model developed by us for the assessment of camouflage using digital image processing techniques. The main topic of Camaeleon is a filter bank with bandpass-filters which are similar to the filters constituted by the receptive fields of the neurons in the early stages of the visual cortex. It is possible to obtain estimates of local energy (that is local contrast), local spatial frequency and local edge orientation from images processes by such filters. These features appear to be the most important concerning separation of figure and ground, that is object detection. The histograms of these features--for object and background separately--can be calculated and compared to obtain measures for similarity between object and background. At present, a functional description between calculated measures of similarity and detection probability derived from field studies is prepared. First results show sufficient correlation between similarity measures and detection probability for practical purposes of camouflage assessment and development.