The virtual point light source model the practical realisation of photometric stereo for dynamic surface inspection

Abstract

The implications of using commercially available non-collimated and distributed illuminates for the application of photometric stereo to dynamic surface inspection tasks are considered. A new form of lighting model, termed the virtual point light source model, is proposed for modelling real distributed illuminates in relative close proximity. The new technique has application for the two- and three-dimensional inspection of moving surfaces using an innovative technique known as dynamic photometric stereo. Such surface inspection tasks have previously been considered difficult or impossible to undertake using conventional imaging techniques. Experimental results are presented in the paper. © Springer-Verlag Berlin Heidelberg 2005.