Feng Lu, Yasuyuki Matsushita, Imari Sato, Takahiro Okabe, and Yoichi Sato, “From Intensity Profile to Surface Normal: Photometric Stereo for Unknown Light Sources and Isotropic Reflectances”, IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI), 2015. vol. 37, no. 10, pp. 1999-2012, October 2015. (DOI: 10.1109/TPAMI.2015.2389841)
Wiennat Mongkulmann, Takahiro Okabe, and Yoichi Sato, “Photometric stereo with auto-radiometric calibration”, in Proc. IEEE Workshop on Color and Photometry in Computer Vision (CPCV2011), pp. 753-758 (ICCV Workshops 2011), pp. 753-758, November 2011.