Background-aware colourisation technique for Augmented Reality applications

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 to automatically select colours of virtual objects by using three different strategies according to the use case scenarios. In particular, the strategies automatically change the colours of augmented objects in an AR scenario by taking into consideration the colours of the real background. The proposed AR colourisation technique was assessed with a user study that focused on three different case studies. Interesting results were also obtained, showing the potential of the proposed technique.