2R. Zhang and P. S. Tsai. Shape from Shading:A Survey[J]. IEEE Trans. Patter Analysis and Machine Intelligence, 1999 , 21(8): 690-705.
3B. K. P. Horn. Shape from shading: A method for Obtaining the Shape of a Smooth Opaque Object from One View [J]. Ph. D. dissertation, Massachusetts Inst. of Technology, 1970.
4A. Tankus, N. Sochen, and Y. Yeshurun. A new perspective [on] Shape - from - Shading [J]. In Proceedings of the of IEEE International Conference on Computer Vision, volume Ⅱ, pages 862- 869, Nice, France, Oct. 2003.