Work memories in Super 8: Searching a frame quality metric for movie restoration assessment.

• Image quality metrics in the context of movie restoration. • Use and test of some metrics as tool for restorers. • A single metric is not sufficient to assess the quality of a frame. This paper describes the digital acquisition and restoration of a Super 8 documentary on the origins of citizens' awareness on paper recycling in the city of Brescia, Lombardy, northern Italy. This film is currently stored in Fondazione ASM archives, and its acquisition is part of a larger project of preservation of industrial memories in Italy. Here we describe the tools used for the acquisition and the post-processing with a Spatial Colour Algorithm (SCA) for unsupervised colour and contrast enhancement. This method provides a semi-automatic image restoration, whose quality has been tested through different evaluations. In this paper, some advantages of the use of SCAs in the restoration pipeline are presented, together with a preliminary discussion on the problem of assessing frame restoration results. To this aim, we present objective vs. subjective evaluation, and some issues associated with this complex task. The most used full-reference and no-reference metrics have been used, together with alternative low-level descriptors. Data and examples are presented and discussed. [ABSTRACT FROM AUTHOR]