用於MPEG視訊的資料隱藏與浮水印新技術與其應用之研究

Abstract

伴隨著資訊科技的發展，越來越多的人利用網際網路來傳送MPEG視訊檔案。因此，MPEG視訊檔案非常適合用來傳輸秘密資訊到接收端。在本篇論文中，我們針對MPEG視訊的許多不同應用，提出多個資料隱藏與數位浮水印技術。首先針對秘密通訊，提出一個可以將秘密資訊隱藏在MPEG視訊檔案中的方法，此方法能有效和正確地使用MPEG視訊中的資訊來隱藏資料，這些資訊包括了頻域係數與動態向量。另一方面，先進的資訊科技同時也造成MPEG視訊很容易遭到非法盜用與竄改，因此發展適當的技術來作MPEG視訊的驗證與版權保護是非常需要的。在本論文研究中，我們利用資訊隱藏的技術來作到MPEG視訊的完整性與真實性的驗證，此方法不但能偵測視訊檔案是否有遭到非法竄改，同時也能呈現視訊是如何遭到竄改並定位出遭到竄改的區域。針對MPEG視訊的版權保護，我們也提出了兩個方法。第一個方法是利用不可視的強韌浮水印技術作間接的版權保護，第二個方法是利用可視浮水印的技術作直接的版權保護。實驗結果證明了所提出方法是可行的。

With the advance of information technologies, more and more people are using the Internet for transmitting MPEG videos. Consequently, MPEG videos become suitable cover files for carrying secret data to receiver sites. In this study, several methods for data hiding and watermarking are proposed for various applications using MPEG videos. Proposed first is a method for hiding secret data into MPEG videos for covert communication. Information, including frequency coefficients and motion vectors, in an MPEG video is utilized efficiently and properly in this method to hide data. On the other hand, the advance of information technologies also brings us the serious problem of misuses or tampering of MPEG videos. Therefore, it is compulsory to develop appropriate methods for video authentication and copyright protection. For the purpose of verifying the fidelity and integrity of MPEG videos, a video authentication method based on information hiding techniques is proposed next in this study. The method not only can check whether a video has been tampered with, but also can show where and how the tampering was conducted. For the protection of MPEG video copyrights, two methods based on invisible watermarking and visible watermarking techniques, respectively, are proposed finally in this study, the former being robust for indirect copyright protection, and the latter useful for direct protection. Good experimental results prove the feasibility of the proposed methods.