  Purpose: This article develops theoretical, algorithmic, perceptual, and
interaction aspects of script legibility enhancement in the visible light
spectrum for the purpose of scholarly editing of papyri texts. - Methods: Novel
legibility enhancement algorithms based on color processing and visual
illusions are proposed and compared to classic methods. A user experience
experiment was carried out to evaluate the solutions and better understand the
problem on an empirical basis. - Results: (1) The proposed methods outperformed
the comparison methods. (2) The methods that most successfully enhanced script
legibility were those that leverage human perception. (3) Users exhibited a
broad behavioral spectrum of text-deciphering strategies, under the influence
of factors such as personality and social conditioning, tasks and application
domains, expertise level and image quality, and affordances of software,
hardware, and interfaces. No single method satisfied all factor configurations.
Therefore, using synergetically a range of enhancement methods and interaction
modalities is suggested for optimal results and user satisfaction. (4) A
paradigm of legibility enhancement for critical applications is outlined,
comprising the following criteria: interpreting images skeptically; approaching
enhancement as a system problem; considering all image structures as potential
information; deriving interpretations from connections across distinct spatial
locations; and making uncertainty and alternative interpretations explicit,
both visually and numerically.
