Range maps have been actively studied in the last few years in the context of depth perception in natural
scenes. With the availability of co-registered luminance information, we have the ability to examine and
model the statistical relationships between luminance, range and disparity. In this study, we find that a onesided
generalized gaussian distribution closely fits the prior of the range gradient. This finding sheds new
light on statistical modeling of 2D and 3D image features in natural scenes.