Dynamic photometric stereo-a new technique for moving surface analysis

This paper describes a novel approach for two- and three-dimensional surface data capture from moving surfaces based upon an evolution of the existing photometric stereo (PS) technique. Limitations in current methods are described, together with the potential benefits of applying PS and the particular need for a new dynamic form of the method. Important issues relating to conventional idealised PS model assumptions are considered in the context of realising useful practical application, including in particular the modelling of real illuminates. Several possible techniques for achieving dynamic PS are considered and a new technique termed narrow infrared photometric stereo (NIRPS) introduced. New potential application areas range from the continuous inspection of fast moving surfaces typically encountered in numerous industrial processes to three-dimensional surface topographic texture acquisition in the field using portable hand-held technology. A selection of experimental results is presented in the paper.