A coding technique for the contours in smoothly perfect eight-connectivitybased on two-stage motion compensation

In this paper, a new contour-coding technique for object-oriented video cod ing is proposed. In our approach, the two-stage motion compensation techniq ue is considered, in order to cope with the rather complex motion of the ob ject. While the object-based motion compensation is performed in the first stage, the second-stage motion compensation is carried out to search the be st match of the contours, which are not motion compensated in the first sta ge. Also, by introducing the notion of the error band, the current contours can be properly fitted to the motion-compensated contours using the interf rame relationship of the contours, In addition, an efficient technique for encoding the contours, simplified by the majority filter, is also proposed. From the simulation result, it is shown that the proposed technique provid es better performance than the content-based arithmetic encoding, especiall y when lossy encoding is allowed, Moreover, by varying the width N of the e rror band, it is shown that the bit amount for the shape information can be adjusted according to the channel condition.