A Spectral Approach to Digitally Restore a Faded Agfacolor Print from 1945

Abstract

The negative-positive chromogenic process, despite being an important milestone in the evolution of color motion picture film technology, exhibits significant fading of its image dyes, leading to the loss of chromatic integrity. A complete spectral approach for the digital restoration of chromogenic film is proposed. A materialbased image processing method allows to extract the residual color information associated with the analytical densities, selectively enhance the faded dyes, and finally recreate the original aesthetics by associating the spectral properties of the film stock.

Digital Unfading of Chromogenic Film Informed by Its Spectral Densities

“…The proposed digital restoration method presented here is the extension of two ready published works, the first of which laid the foundation of developing this approa [35] and the latter described the restoration of a faded Agfacolor chromogenic print fro 1945 as case study substantiating the approach [36]. For our current case study of the fi selected China Girls samples, the determination of the spectral densities of the samp (see Section 2.1) was essential to reconstruct, to the best of our knowledge, the origin aesthetics of the faded film.…”

“…This is the suitable dye purification protocol for cyan fading. In the case of yellow fading, which was the type of fading affecting the Agfacolor print that has been restored as a part of the previous case study [36], the red capture is purified first to obtain the cyan layer and then the blue capture is purified to obtain the yellow layer.…”