Image Rendering Based On A Spatial Extension Of The Ciecam02

With the multiplicity of imaging devices, the color quality and portability have become a very challenging problem. Moreover, a color is perceived with regards to its environment So, if this environment changes it implies a change in the perceived color. In order to address this influence, the CIE (Commission Internationale de l'eclairage) has standardized a tool named color appearance model (CIECAM97* CIECAM02). These models are able to take into account many phenomena related to human vision of color and can predict the color of a stimulus, function of its observations conditions. However, these models do not deal with the influence of spatial frequencies which can have a big impact on our perception. In this paper, we present an extended version of the CIECAM02 that integrates a spatial model correcting the color in relation to its spatial frequency. Moreover, the previous model has been modified to deal with images and not only single stimulus. The main difference with the rendering models (e.g. iCAM) lies in the fact that the proposed model, takes into account the spatial repartition of a pixel in addition to its environment. The obtained results are sound and demonstrate the efficiency of the proposed extension. This has been checked thanks to a psychophysical study where observers were assigned the task of assessing the quality of the improved version in comparison to the original.