不論在商業影片或一般的自攝影片，鏡頭拉近推遠都是很常出現的動作。由於鏡頭拉近推遠的移動特性，現行視訊編碼標準所採用的區塊導向移動估算演算法並沒有辦法將受到鏡頭拉近推遠所影響的物體移動處理的很好，也因此造成了預測和編碼效率上的不彰。
基於鏡頭拉近推遠的特性，本篇論文提出了一個有別於現有總體運動分析的方法來檢查一段影片是否有受到鏡頭拉近推遠動作所影響。若一段影片有受到鏡頭拉近推遠動作所影響，我們可以預測鏡頭拉近推遠的速度。根據此預測出來的速度，我們提出了一個點導向的移動補償演算法，並得以預測此畫面中每一個點的移動向量，進而預測整個畫面。我們還提出了一個結合了鏡頭拉近推遠移動補償演算法，以及傳統區塊導向移動估算演算法的綜合演算法。此演算法不只具有我們所提出的鏡頭拉近推遠移動補償演算法的高畫面品質，同時結合了現行的區塊導向移動估算演算法，並且進一步提升了編碼效率。

關鍵詞︰鏡頭拉近推遠，總體運動分析，區塊導向移動估算，移動向量，移動補償。

Camera zooming motion is very common in both commercial movies or home made videos. However, since the property of the moving motion caused by camera zooming, block based motion estimation method in current video coding standard couldn’t process video sequences with camera zooming motion well.
Base on property of camera zooming motion, we proposed a zooming motion estimation method which is different from present global motion analysis method. If we estimate that there is a camera zooming motion, we can further estimate the camera zooming speed. We propose a camera zooming motion compensation algorithm which can estimate the motion vector of each pixel by the camera zooming speed to reconstruct whole frame. We further propose a combined method which combines our camera zooming motion compensation algorithm with traditional block based motion estimation method. The combined method not only has high visual and image quality, but also improves the coding efficiency compared to block based motion estimation.

Key words: camera zooming motion; global motion analysis; block based motion estimation; motion vector; motion compensation.

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