在影片處理中，不管是物體的切割與檢索、全場景的應用，甚至內容式的影片檢索與擷取等，都與攝影機運動參數估測息息相關。在這些應用中，解壓縮與攝影機運動參數估測所耗費的時間與資源都相當大。因此，如果能夠善於利用壓縮資訊來估測攝影機運動參數的話，將可以增加處理的效率。
在這篇論文中，我們解決了兩個利用運動向量來估測攝影機運動的問題，一個是畫面群之間連結的問題，透過B畫面的往前與往後參考，來連結不同畫面群的P與I畫面。另外，由於運動向量的不確定性，使得攝影機運動參數估測誤差變大。我們提出一個二次估測的方法來將例外情況排除，並且得到不錯的結果。最後，我們建立一個全場景圖系統，將攝影機運動參數應用在全場景圖上。

Camera motion estimation is very important from a video processing view. Video application, including object segmentation and tracking, mosaic and content-based video indexing and retrieval, based on the video content should represent motion efficiently. Since, to decode MPEG video and estimate camera motion is extremely time-consuming. To obtain efficient estimates of camera motion by directly processing data easily obtained from MPEG-compressed video becomes more important.
In this thesis, two main concerns of camera motion estimation from motion vector are addressed. Firstly, we introduce the connection from a GOP to next GOP by B-frame bidirectional reference. Secondly, we propose a 2-pass camera motion estimation to cope with outliers caused by the uncertainty of motion vectors directly from MPEG video format. Experiment results show that the 2-pass camera motion estimation method is reliable. Finally, we have developed a mosaic system by applying the proposed method.

1. 賴建明、王明習, “以物體運動為基礎之影片檢索與擷取”, 影像與識別, Vol. 8, No. 1, March, 2002, pp.45-54

2. MPEG ORG, http://www.mpeg.org/

3. ISO 11172, “Coding of Moving Pictures and Associated Audio – for Digital Storage Media at up to about 1.5Mbit/s.”

4. S. Jeannin, R. Jasinschi and B. Mory et al., “Motion Descriptors for Content-based Video Representation,” Signal Processing: Image Communication Journal, 16(1,2), pp.59-85, 2000.

5. M. V. Srinivasan, S. Venkatesh and R. Hosie, “Qualitative Estimation of Camera Motion Parameters from Video Sequences,” Pattern Reconition, 30(4), pp.593-606, 1997.

6. J.-I. Park, N. Yagi, K. Enami, K. Aizawa, M. Hatori, “Estimation of Camera Parameters for Image Sequence for model-based Video Coding”, IEEE Transactions on Circuits and Systems for Video Technology, 4(3), pp.288-296, 1994.

7. P. Salembier and T. Sikora, Introduction to MPEG-7, John Wiley & Sons, 2002

8. Y. P. Tan, S. R. Kulkarni, P. J. Ramadge, ”A New Method for Camera Motion Parameter Estimation”, In Proc International Conference on Image Processing, pp.406～409, 1995.

9. W. H. Press et.al., Numerical Receipt in C, 2nd ed., Cambridge Univ. Press, 1992.

10. R. Wang, T. Huang, “Fast Camera Motion Analysis in MPEG Domain”, ICIP, pp. 691-694, 1999.

11. E.-T. Kim, “Robust 3-D Camera Motion Parameter Estimation with Application to Video Coding”, ICASSP, pp. 14-19, 2006.

12. W. J. Gillespie and D. T. Nguyen, “Robust Estimation of Camera Motion in MPEG Domain”, TENCON, pp. 395-398, 2004.