Multispectral Film Scanning
and Handling of Multispectral Moving Images

Lecture delivered at The Reel Thing XLIV during the AMIA Conference in Portland, Oregon, United Stated of America, from 28 November to 1 December 2018.


We tend to think of the film system as a single thing, but in fact the physical history ot the medium is considerably more complicated, and considerably less documented than the unary meme of cinema might imply. So further understanding of the technical work to be done depends on research. We have reached a point in the technical history of moving images where technologies that where previously irrelevant or inaccessible can now be brought to bear on solving the problems of how to capture and represent historical moving images in a digital media-sphere – we can deploy new technical means to interrogate the film artefacts that we encounter in the archives. One area rich in research targets is colour in film. Since the inception of the medium, colour has been the locus of continual experimentations, and the result is a plethora of processes that cannot be migrated by technical single system. It is current practice in fine art conservation and restoration to approach analysis of colour by multispectral scanning, and it would appear that gradually, we will deploy some of those methods in the analysis of historical colour in film. The multispectral approach ay be useful for “non-standard” colour systems, such as the two-colour additive ones from the 1920s and 1930s, or for very decomposed reels, where any additional bit of information can make the difference during the restoration. Inspired by Jim Lindner’s Filmic project, Reto Kromer and his team have been conducting research on colour. The creation of their ad-hoc multispectral scanner and the development of a video codec to work with this kind of content will be discussed, including experiments using the restoration suite Diamant.


Having graduated in mathematics and computer science, Reto Kromer became involved in audio-visual conservation and restoration more than thirty years ago. He was head of preservation at the Cinémathèque suisse (Swiss National Film Archive), and lecturer at the University of Lausanne and the Academy of Fine Arts Vienna.

He has been running his own preservation company, AV Preservation by, and lecturing at the Bern University of Applied Sciences. His current research includes colour spaces, look-up tables and codec programming and emulation.