In this article, the authors propose a method to estimate the reflectance property from refocused images from a light source reflected on an object. The blurred information of the light source on the surface of the object is expected to be a practical method to estimate the reflectance property, although various methods have previously been proposed. Because the degree of blurred information is changed with the position of focus in the camera, the authors introduce a light field camera that can change the position of focus after the image is captured. In this research, the authors chose the refocused image where the light source is focused through the reflection on the object surface. Based on the blurred information of the focused light source, they estimate the reflectance property of the object. The estimated reflectance property is applied to inverse rendering for auto material appearance balancing.
Norimichi Tsumura, Kaori Baba, Shoji Yamamoto, Masao Sambongi, "Estimating the Reflectance Property from Refocused Images and its Application to Auto Material Appearance Balancing 1" in Journal of Imaging Science and Technology, 2015, pp 030501-1 - 030501-6, https://doi.org/10.2352/J.ImagingSci.Technol.2015.59.3.030501