Analysis of hair shine using rendering and subjective evaluation.

Hair shine is a very desirable attribute to consumers within the cosmetic industry and is an important indicator of hair health. However, perceptual evaluation of shine is a complex task and it is known that even subtle manipulation of local hair properties like clolour, thickness, style or global properties such a lighting and environment can affect the evaluation. In this paper, we are interested in the charcateristics that affect the realism of hair along with the perception of shine. Firstly, we constructed a hair setup to reduce the number of variables that affect the perception. Using physically based hair shading models with added parameters to control some physical characteristics, we rendered images of hair in the setup and asked participants to assess its realism, health, naturalness and shine through three different experiments. Our results provide new insights on how hair is perceived, the factors that affect its realism and the potential of using Computer Graphics (CG) techniques in the cosmetic industry to replace physical testing.