Shozo Kondo, Tong Xu, Hidenori Tanaka, Manas Sangwarasil, Kiyoaki Atsuta. Shape and source from shading using zero crossings. In 11th IAPR International Conference on Pattern Recognition, ICPR 1992. Conference A: Computer Vision and Applications, The Hague, Netherlands, August 30-September 3, 1992. pages 534-537, IEEE, 1992. [doi]
Abstract is missing.