以快速著色技術為基礎之視訊廣播系統及數位權利管理機制

Abstract

對於娛樂工業來說，視訊廣播系統為了數位內容傳輸提供了大量的商業機會，但同時對於客制化服務的需求也越來越高，像是針對不同客戶提供不同畫質的影片或加入每個客戶的辨識碼(fingerprint code)等。然而，客制化的需求跟視訊廣播系統在觀念上是相衝突的。客制化會使得每個客戶所接收到的影片不同。因此，原本只需傳送一份影片，然後再廣播給所有客戶的概念將無法實現。 針對這個問題，我們提出一個以快速著色機制為基礎且提供數位權利管理機制的視訊廣播系統架構。在我們的系統中，我們設計出一個可以即時反著色與著色的演算法，然後將其整合進現今的影像編碼系統。然後，我們透過這個修改過的編碼系統來解決客制化服務對視訊廣播造成的問題。在這套方法中，我們將原本的影片串流分成兩個部份：其中一部分，灰階的影像將經由廣播的方式傳送給每一個客戶;另一部份，彩色的部份會先經過我們反著色的技術轉成色彩種子，然後在一條低頻寬需求的網路上透過一對一傳輸的方法傳送給每一個使用者，而我們先前提到的客制化服務，包括針對不同客戶提供不同畫質的影片或加入每個客戶的辨識碼的功能，將會透過針對不同用途進行修改的色彩種子來實現。對於每個客戶來說，他們所需的只是使用著色演算法將色彩種子與灰階影像重組起來，以得到一份客制化的高畫質彩色影像。 我們提出的系統對於有著兩個以上的共謀者的平均式共謀攻擊顯示出優秀的抵抗能力。另一方面，我們提出的系統可以藉由動態調整色彩種子去獲得不同的影像畫質。影像提供者不必為了不同畫質儲存多份影像在資料庫裡，可以針對付費的多寡，提供不同畫質的影像給客戶。

Distributing video contents via broadcasting network has become a promising business opportunity for entertainment industry. More and more related customized services, such as traitor-tracing scheme or QoS service, are required. However, end-to-end customized services inherently conflict with the requirements of broadcasting system. Furthermore, storing different customized versions of video will also result in bandwidth inefficiency. We proposed a real-time DRM-enabled video broadcast systems based on efficient colorization scheme. In our proposed system, we provide a real-time decolorization and colorization method and incorporate it into existing codecs. We use it to solve problems of bandwidth inefficiency of broadcast system, as well as the integration difficulties with customized services. We divide original video into two components. On the one hand, gray-level video sequences are delivered to each client via broadcast mechanisms, like multicast to reduce the overhead in server processing and network bandwidth. On the other hand, color seeds for customized functionality, such as fingerprinting or QoS, are delivered to each client through low-bandwidth auxiliary connections and then used to generate high-quality full-color videos with slight differences between versions received by each client device. Our proposed system shows good resistance to collusion attacks where two or more users cooperate to generate an illegal copy. Moreover, our system can facilitate the goal that users can get video programs based on the price they paid by dynamic quality adjusting.