Representation of cultural objects by image sets with directional illumination

Abstract

In a dome illumination system, many different images can be captured in pixel register from the same viewpoint, each illuminated from a different direction. This is a much richer representation than a single image, and has many applications in cultural heritage for the digitising and display of objects that are flattish with surface relief, such as coins, medals, fossils, rock art, incised tablets, bas reliefs, engravings, canvas paintings, etc. The image sets can be used in three ways: (1) visualisation by interactive movement of a virtual light source over the enclosing hemisphere; (2) 3D reconstruction of the object surface; (3) modelling of the specular highlights from the surface and hence realistic rendering.