Background-Aware Colorization Technique for Augmented Reality Applications

Abstract

A major challenge in the field of Augmented Reality (AR) is the way in which augmented information is presented in a wide range of uncontrollable environmental conditions. In fact, the variability of colours and illumination conditions of the real environment makes it difficult to choose the most suitable appearance properties for augmented contents. In many AR applications, the colours of virtual objects play a crucial role in blending digital information into the real environment, therefore these colours should be selected according to the appearance of the real background. In some use cases, the colours of virtual objects need to be harmonised with the ones of the real environment; in other cases, the colours should be chosen to ensure the visibility (e.g. maximizing the contrast) of the augmented data with respect to the background. To this end, the paper presents a background-aware colourisation technique that allows for selecting virtual objects’ colours in accordance with the real environment in real-time. Given an arbitrary real background, virtual objects’ colours are automatically chosen according to three different strategies, i.e. harmonic, disharmonic, and balanced. The proposed AR colourisation technique was assessed with a user study that focused on three different case studies. The results were promising and suggest the potential of the proposed technique for many different application areas. In particular, disharmonic and balanced strategies ensured the distinctiveness of virtual objects according to the real background. Instead, the harmonic strategy was less effective in the case of colourful complex AR scenarios.

Keywords

• Augmented reality
• image processing
• colourisation
• colour harmonisation
• user studies