Perception of human skin conditions and image statistics.

The color and texture of human skin provide useful information in evaluating a person's health, emotion, attractiveness, and so on. Whereas the appearance of skin is a product of optical properties originating from its own biophysical substrates, recent psychophysical studies of surface material perception indicate a possibility that humans can perceive skin conditions from relatively simple image features such as texture statistics. The present study investigated the structure of multidimensional perceptual rating data for 289 female skin images and analyzed diagnostic low-level image statistics. We found that various skin appearances can be summarized into two dimensions, pleasantness and glossiness, and either dimension is well correlated with a small set of subband luminance and color statistics. We confirmed that manipulations of these critical image statistics significantly alter the appearance of skin in the expected direction. The results support a notion that humans perceive skin properties essentially based on two cardinal dimensions as predicted by simple image statistics.