Relighting Hair in a Single Image
Details
Simulating our own impression with a new hairstyle would be useful when we select a hairstyle. However, if we simply overlay a hairstyle image onto a facial image, the composited result looks unnatural due to the mismatching of lighting conditions between the facial and hair images. In this paper, we present a novel method for relighting hair in a single image to modify the lighting effect of hair. The proposed method estimates the reflectance of hair based on Kajiya-Kay model, which requires the three-dimensional vectors of hair directions. To obtain such hair directions, we first extract a two-dimensional vector field of hair direction from the input image, and then estimate three-dimensional hair directions as well as the light direction. Using this information, various relighting results can be obtained based on Kajiya-Kay model by changing the light color, direction and brightness.
