Designing Spectral Imaging Methodologies for Works of Art

Imaging Science’s major purpose is to render visible specific features by developing an effective interaction between the "tools of the trade" (radiation sources, optical elements, sensors) and the object that is analyzed. To obtain this effective interaction, a deep understanding of the physical phenomena involved and a dose of creativity are required. Among the Imaging Science’s wide range of applications (medical, environmental, forensic, etc.) is Cultural Heritage. This is a particular challenging sector, due to the inestimable value of certain artworks and the contrasts that can arise between different interpretations of restoration ethics. A selection of case studies from internationally renowned collections is presented. The selection highlights particularly challenging analyses that required a change of perspective and offered new interpretations. Focusing on paintings, photography and motion picture film, several subjects are discussed: optical detection of dust and scratches on photographic film, virtual cleaning of paintings with discolored varnish, UV-VIS-NIR micro-spectrophotometry for the analysis of dispersed pigment particles, virtual rejuvenation of paintings with degraded pigments, film aesthetics and its rendition with digital cinema, the jarring contrast “strict conservators”, who strive to protect the artwork integrity before anything else, and “technology enthusiasts”, who appreciate the benefits of “enhanced” representations of historical films.