Electronic imaging: a tool for the reconstruction of faded color photographs and color movies
Rudolf Gschwind, Franziska S. Frey, Lukas Rosenthaler · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1995
A method to restore faded color materials by digital image processing is presented. The algorithms used for the reconstruction are based on photographic experiments, i.e., on accelerated fading tests of various photographic materials. The densities of the original and the faded materials were measured. Based on this data, a mathematical model for fading can be described by a linear equation. The faded image is digitized using a scanner of high spatial and photometric resolution. For good spectral resolution, channel separations are done with narrow- band interference filters. The original colors are reconstructed by applying the inverse of the facing equation. The corrected image is exposed with a high-resolution film recorder on color film. The method shows good results for color slides, prints, and 16 mm movies.