This paper presents a novel algorithm for detecting moving objects from a static background scene that contains shading and shadows using color images. We develop a robust and e ciently computed background subtraction algorithm that is able to cope with local illumination changes, such as shadows and highlights, as well as global illumination changes. The algorithm is based on a proposed computational color model which separates the brightness from the chromaticity component. We have applied this method to real image sequences of both indoor and outdoor scenes. The results, which demonstrate the system's performance, and some speed up techniques we employed in our implementation are also shown.