Variable size block matching motion compensation for object-based video coding   R.A. Packwood & M.K. Steliaros & G.R. Martin.    Proceedings of IEE 6th International Conference on Image Processing & its Applications (IPA'97), Dublin, Ireland, July 1997, pp 56-60.    Abstract: Recently developed object-based video coding schemes require the estimation of motion in arbitrary-shaped objects. A quad-tree structured variable size block matching technique is described. The inherent motion is represented by significantly fewer blocks than if conventional fixed size block matching had been used to provide a similar quality prediction.