近年來，由於數位時代的來臨，數位資料廣泛的透過網際網路快速散播到世界各地，因此任何人可以輕易取得數位資料並大量複製與修改，數位資料之智慧財產權的問題日趨重要。因此，如何有效保護有價媒體自然成為目前重要的研究議題，而數位浮水印即是解決此一問題的重要技術之一。尤其是在臉部影像的移花接木方面，讓現今的人們感到恐懼及不安，本篇論文將著重於利用數位浮水印技術對影像內容做移花接木驗證。
本論文提出一種具有移花接木驗證之數位浮水印技術，它能夠正確驗證出數位影像是否有被移花接木。首先我們會先利用人臉偵測及眼球偵測技術，將數位影像的眼球中心位置求出，根據眼球位置設計出內部浮水印的視窗大小，再將格子編碼的描述(trellis code description)利用內部浮水印技術(inner watermarking technique)作展頻植入。然後再將一序列的浮水印位元，將浮水印經過格子編碼(trellis encode)，再將編碼後的浮水印利用外部浮水印技術(outer watermarking technique)作植入。我們再根據萃取出來的浮水印經過格子解碼(trellis decode)，產生出來的累加路徑計算值(cumulative path metric)，由它來做一個依據，大於所設定的臨界值，就會驗證到此數位影像遭到移花接木。實驗結果証明我們所提出的方法可以檢查出數位影像是否有遭到移花接木。

In this digital age, digital information is broadly transferred via internet. Digital information can be co pied or modified in large quantities. Copyright issues have grown more and more important. Thus, how to protect the valuable media effectively becomes a crucial theme for researching. Digital watermarking is one of major techniques to solve this problem. In this thesis ,we want to fight grafting in facial images by watermarking.
We present a digital watermarking scheme that checks graft authentication for facial images. This scheme involves two stages of watermarking to which we refer an inner watermarking and outer watermarking. First we use face detection and eyes detection to find eye- center locations in a digital image. According to eyes location ,we choose window size of the inner watermark. We use the spectrum spreading inner watermarking to embed the description of a trellis encoder. A sequence of watermark bits that carry useful side information are then embedded into the whole area of the original image by trellis encoding. This stage is called the outer watermarking. Then we perform the extraction of outer watermark by trellis decoding. After that, the cumulative path metric is obtained. If it is greater than the threshold value, we decide that the digital image had been grafted. The result demonstrates that our method can distinguish between grafted and ungrafted images.

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