The paper A Comparison of Color Features for Visual Concept Classification by Koen van de Sande, Theo Gevers, and Cees Snoek is available online now. The paper improves upon the CVPR 2008 paper below by considering also the points at which color features are extracted. Hence, different point sampling strategies based on Harris-Laplace salient points, dense sampling and the spatial pyramid are studied in concert with color features.