隨著科技的發展，3D 資訊領域逐漸成為當今世代的發展趨勢，3D相關產業也隨之增加，如三維掃描器、三維列印機以及3D繪圖軟體。透過商用或免費繪圖軟體亦或是三維掃描器，消費者可以輕易創作專屬的彩色數位作品。此外隨著網路時代的來臨，資訊傳遞的方式較以往更不受空間或時間限制，藉由網路取得資訊作品亦是方便，數位資訊的產生也會隨之增加，因此而衍伸出智慧財產權的問題，而浮水印也是資訊安全應用上的一種版權宣告的方式。
本研究主要目標為對三維模型的版權宣告的方法，提出一種藉由模型顏色以色差的方式來藏匿浮水印，在原始的3D 模型嵌入一個JND (Just noticeable difference)人眼察覺不出的色差顏色，透過渲染方式將特定虛擬光源渲染投射在 3D 模型上，使得浮水印和原始的模型之間產生可以被人眼觀察出的色差，以達到版權宣告的方式，並且透過人因實驗來評價其隱藏以及防偽效果之可行性。
實驗結果發現，所提出的方法是可行的，且探討隱藏浮水印的方法中發現，人眼對於明度上的改變較為敏感，因此改變色度上的變化方式，其浮水印隱藏性較好，讓人眼察覺不到浮水印的存在。而解碼燈光提取浮水印時，可選擇該藏匿的浮水印顏色之對立色當作其解碼燈光可以有較好效果。

With the rapid development of technology, the 3D field is getting popular. The 3D related products massively increase, such as the 3D scanner, 3D printer and 3D graphics software. By using these products, consumers can generate their own 3D models easily. Simultaneously, the digital media and network are getting common as well. Nowadays, the delivering method is different from the past. Most information are delivered and transferred on internet, because the internet platform is convenient to communicate and share information. Consequently, if massive information are generated, the copyright issue will get important. In addition, the digital watermarking becomes a significant solution for hiding copyright information.
This paper focuses on the copyright issue of digital 3D models. Therefore, we propose a method by adjusting the original texture color of digital 3D models to generate an invisible color difference watermark. The color adjustment method will generate a serious of JND (just noticeable difference) color as a part of watermark. After adding watermark, we can apply a specific virtual lighting to render the 3D model. As a result, the color difference between the watermark and the original texture will be enlarged to be noticed. Finally, we will evaluate the feasibility of the proposed method by questionnaire.
The experimental results show that the proposed method is feasible. In designing the color of hidden watermarks, the lightness of hidden color is too sensitive to human vision system. Therefore, adjusting chromatic information is better for selecting the color of watermark. In addition, for selecting the decode light, opponent colors of watermark color will be better for showing up the watermark.

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