Abstract—To implement the photometric stereo technique, the radiance distribution of the respective light sources from the different illumination directions must be accurately known. Most previous work has tended to assume distance point sources, so that a collimated and uniform illumination distribution can be approximated, thereby allowing the photometric stereo problem to be easily solved in a linear way. However, there can be significant practical difficulties in realizing such idealized light sources in real world applications. In addition, the strategy of using distant light sources produces a low signal/noise ratio for the system, and is also unsuitable for applications where setup space is limited. These problems potentially limit new opportunities for the wider applications of photometric stereo beyond the research laboratory in evolving areas such as industrial inspection, security and medical applications. This paper proposes a compensation method for illumination radiance to allow the possibility of employing normal low-cost commercial light sources. A flat diffuse surface with either homogeneous or heterogeneous albedo distribution is used to sample the radiance distribution before implementing photometric stereo. The unevenly distributed light radiance is eliminated by using the acquired reference information. The experimental results demonstrate the efficacy of the proposed method.
Index Terms—Light source, radiance, photometric stereo, compensation.
The authors are with the Machine Vision Laboratory, University of the West of England, Bristol, BS16 1QY, UK (e-mail: email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org).
Cite: Jiuai Sun, Melvyn Smith, Lyndon Smith, and Abdul Farooq, "Sampling Light Field for Photometric Stereo," International Journal of Computer Theory and Engineering vol. 5, no. 1, pp. 14-18, 2013.