The aim of this project is to find a motion estimation method that works in combination with block matching in order to reduce the visible artifacts. The proposed solution tries to extract the real motions taking place in a sequence. The developed algorithm is a region based motion estimator. We associate to regions of general shape motion parameters which describe an ane transformation on the plane. The traditional block matching is then used for smaller transformations. The developed algorithm is iterative. It alternatively considers the motion and the region as being constant and renes the other one according to this hypothesis. The results will show that it converges and leads to good results if big objects are moving in a sequence.