Moving shadow representation based on a level curves decomposition

This paper proposes a new model to represent the moving shadow areas in video sequences. Classical models assume that the ambient light received in a shadow area is constant, but in practice it is not always the case. In order to define a more precise model, the variations of the ambient light are here taken into account thanks to a level curves decomposition of the shadow area. A B-spline approximation of these level curves is introduced in order to get a smooth and compact representation. Experimental results show that this model can efficiently represents shadow areas. Results have been applied to the problem of shadow removal for video editing applications.