一個好的動態估計(motionestimation)演算法應利用過去資訊提供線索於
何處開始搜尋程序。為了獲得高效能，則必需研究動態向量(motion
vectors)的性質。由這些研究發現，對於大部份個案而言其動態向量長
度(motion vector length)是 短的。基於這項研究，在本論文中提出了
兩個快速動態估計(fast motion estimation )演算法。實驗結果顯示它
們大大降低了計算時間。實際上我們所提出方法之速度差不多與3-steps
search一樣快，並且影像重建結果幾乎與完全搜尋(full search)法一樣
好。

A good motion estimation algorithm should use the his- toric
information to provide hints on where to begin the search
process.To obtain high performance, the properties of motion
vectors are studied. From these studies, it is found that the
motion vector lengths are short for most cases. Based on the
studies, two algorithms for fast motion estimation are proposed
in this Thesis. Experimental resu- lts show that they achieve
significant saving on computa- tion time. In particular, they
are as fast as the 3-steps search method and the reconstructed
results are nearly the same as that by the full search method.