A new motion compensation technique using a window which satisfies the perfect reconstruction condition is proposed. The conventional motion compensation using rectangular blocks often gives discontinuities between neighboring motion compensation blocks in the predicted image. The proposed method is based on a window operation to the data which overlaps an area of the conventional motion compensation block. Computer simulation is carried out using MPEG video coding algorithm to evaluate the proposed method. The performance of the proposed method is better than the conventional method in terms of mean square error, and large improvement can be obtained at the block boundaries. This gives a smooth predicted image for a typical MC+DCT coding scheme.