UCLDH Seminar Series: Lindsay MacDonald

Image Sets under Directional Lighting: A Richer Representation of Cultural Heritage Objects

Lindsay MacDonald, 3DIMPact Research Group, Faculty of Engineering, UCL

With a camera on a copystand one obtains a single image of an object with a fixed (usually diffuse) lighting geometry. In a dome illumination system, however, the same camera can be used to capture many different images in pixel register, each illuminated from a different direction. This turns out to be 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. This talk will describe the UCL Dome system and show how 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.