在 H.264/AVC 視訊上做資訊隱藏之研究及 其應用

Abstract

隨著資訊科技的進步，越來越多的網路視訊應用也隨之發展，其中 H.264/AVC的視訊檔案是現今應用最廣的視訊格式。本論文針對H.264/AVC 的視訊檔案，利用資訊隱藏及數位浮水印之技術做秘密傳輸、版權保護及視訊分享之研究與應用。在秘密傳輸方面，我們提出一個大量以及一個最佳化的方法，這兩個方法皆是利用 H.264/AVC視訊檔案的特性來隱藏資料。其中最佳化的方法可在隱藏資料量、視覺影響及壓縮後檔案大小間取得一個最佳結果。在版權保護方面，對於被客戶端下載的 H.264/AVC 視訊檔案，我們提出一個利用主動式可視浮水印技術及限制影片在特定電腦播放的方法來做版權保護。而在秘密分享的應用方面，我們利用邏輯運算從事秘密視訊資料的分享，並將分享出去的資料回藏至視訊當中，最後將分享後的視訊分發給各參與者保管。在所有參與者所擁有的視訊集合起來之後，即可回復成原本的秘密視訊。最後，我們以實驗結果證明了所提方法之可行性。

With the advance of information technologies, more and more digital video applications on the internet have been proposed. H.264/AVC videos are used in a wide variety of applications. In this study, several methods for data hiding applications, namely, covert communication, copyright protection, and video sharing, are proposed using H.264/AVC videos as cover media. For covert communication, we propose a large-volume method and an optimal method for hiding secret data in H.264/AVC videos, based on the use of prediction modes and tree structured motion compensation. The optimal method is a tradeoff between hiding capacity, imperceptibility, and low bit rating. For copyright protection, in order to protect the ownership of downloaded videos at the client site, a method using a removable visible watermarking technique with a scheme for display control on specified computers is proposed. For the application of secret sharing, we share the data of the prediction modes of a secret video based on exclusive-OR operations and hide the resulting share data into the prediction modes of cover videos. The resulting share videos are then distributed to participants to keep. By collecting the share videos owned by all participants, the secret video can be recovered. Good experimental results show the feasibility of the proposed methods.