Machine Vision Cosmology: Solar Regimes of Reflectance Transformation Imaging

This project examines some of the visual codes underlying Reflectance Transformation Imaging (RTI), a digitising workflow enabling virtual relighting within photographic representations of artefacts. Increasingly adopted in the fields of archaeology, conservation and forensics, RTI is one of several processes that have brought imaging workflows in these areas into the age of computational photography, expanding on a long lineage of representational ‘realism’ as the techno-cultural production of ever greater visual disclosure of the material world. The capacity of this application to change the direction of lighting in an image is considered as a gesture of ‘un-fixing’ in relation to photographic history and theories of indexicality, with the structural relationship between object, light source and observer established by RTI inviting a wider set of contextual associations within art, cinema, architecture and cosmology. These contexts inform a set of visual experiments that explore the potential for a critically reflexive artistic practice within this niche field of emergent machine vision.

​Keywords: Reflectance Transformation Imaging (RTI), Polynomial Texture Mapping (PTM), Computational Photography, Archaeology, Conservation, Forensics, Image Mining, Cosmology, Antikythera Mechanism, Salvador Dali, Reflexivity.