Validating the TOD method with identification of real targets : Effects of aspect angle, dynamic imaging and signal processing

How far the eye reaches via camera is quantifiable and modeled with the TOD (triangle orientation discrimination) methodology (Bijl and Hogervorst, 2008 Perception 37 Supplement, this issue). For validation and extension purposes, we studied identification of real objects in several conditions. Objects (two-handheld) were recorded at various distances and angles with an under-sampled uncooled thermal imager. Results: (i) The distance for identification at threshold level was closely predicted by the TOD model, using existing scale criteria for two-handheld objects; (ii) effects of aspect angle were large, yet to nearly half extent predictable from contrast and size changes; (iii) sensor motion had no positive effect, (iv) the benefit of DSR (dynamic super resolution) was smaller than expected; (v) performance with local adaptive contrast enhancement equaled that of manual contrast optimization. The relatively poor performance with motion and DSR are probably due to motion smear, since camera speed was higher than in earlier studies. We conclude that the TOD methodology can predict identification distance for real targets. Effects of camera motion magnitude and smear are not modeled yet