Shadow removal with background difference method based on shadow position and edges attributes

Abstract

This article presents a shadow removal algorithm with background difference method based on shadow position and edges attributes. First, a novel background subtraction method is proposed to obtain moving objects. This method mainly includes three parts, namely detecting the moving regions approximately by calculating the inter-frames differences of symmetrical frames and counting the static index of each probable moving point; modeling for background by the statistics of brightness information and updating this model combining motion templates; then extracting moving objects and its edges. Second, based on the above processing, we suppress shadows in the HSV color space first, then the direction of shadow is determined by shadow edges and positions combining with the horizontal and vertical projections of the edge image, respectively, the position of the shadow is located accurately through proportion method, the shadow can be removed finally. Experimental results indicate that the proposed method is easy to be realized and can determine the direction of the shadow adaptively, then eliminate the shadow and extract the whole moving object accurately, especially when the chrominance invariant principle is ineffective. © 2012 Zhu et al.; licensee Springer.