Validating colour representation in synthetic scenes using a virtual colour checker chart

Evaluating the visible signature of operational platforms has long been a focus of military research. Human observations of targets in the field are perceived to be the most accurate way to assess a target’s visible signature, although the results are limited to conditions observed in the field. Synthetic imagery could potentially enhance visible signature analysis by providing a wider range of target images in differing environmental conditions than is feasible to collect in field trials. In order for synthetic images to be effective, the virtual scenes need to replicate reality as much as possible. Simulating a maritime environment presents many difficult challenges in trying to replicate the lighting effects of the oceanic scenes precisely in a virtual setting. Using the colour checker charts widely used in photography we present a detailed methodology on how to create a virtual colour checker chart in synthetic scenes developed in the commercially available Autodesk Maya software. Our initial investigation shows a significant difference between the theoretical sRGB values calculated under the CIE D65 illuminant and those simulated in Autodesk Maya under the same illuminant. These differences are somewhat expected, and must be accounted for in order for synthetic scenes to be useful in visible signature analysis. The sRGB values measured from a digital photograph taken at a field trial also differed, but this is expected due to possible variations in lighting conditions between the synthetic and real images, the camera’s sRGB output and the spatial resolution of the camera which is currently not modelled in the synthetic scenes.