應用小波轉換於彩色圖片數位浮水印之研究

Digital Watermark of Color Image based on the Wavelet Transform

劉用貴(Yung-Kuei Liu)

指導教授 ： 許通安

中原大學/商學院/資訊管理研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400244

摘要

摘要
無線高速寬頻全數位化多媒體時代的來臨，在網際網路世界中傳送多媒體資料已經非常普遍，而隨著電子商務快速成長，多媒體資料多數以數位化的方式儲存及傳輸。在開放網路的世界中，確保數位影像圖片資料之安全，就成了目前急待解決的問題，由於各式各樣的數位多媒體資料─如聲音、影像、動態影片(如VCD、DVD)、聲頻信號(如MP3)等，在網路上存取容易，且具傳播快、易於複製、傳輸等特性，因此，數位多媒體資料的智慧財產權保護問題益形重要，過去雖然有許多關於相關浮水印嵌入的方法的研究被提出，但大部分的方法都是針對以應用在灰階的電子檔案及灰階影像圖片居多，本研究應用於彩色圖片，以RGB彩色模型，並以簡單的影像資料平均分佈於原圖區塊之方法，利用小波二次轉換分解成次頻帶，實驗證明於LL2頻帶嵌入數位浮水印資料可得到最佳的強健效果。浮水印資料加密後經小波轉換並適當擴展，調整嵌入係數嵌入影像的第三階小波轉換頻帶，達成資料隱藏的目的。取出的浮水印可以再經過修補運算，以提昇浮水印的相似度。本文所提的數位浮水印具有不可視性（imperceptibility）、透明度(transparency)、強健度(robustness)與安全性(security)之特性，以保障電子商務網路上數位彩色影像圖片智慧財產權為目的。

關鍵字

彩色模型 ； 小波轉換 ； 電子商務 ； 浮水印

並列摘要

ABSTRACT

With the era of the wireless, high-speed broadband and overall-digitalized multimedia coming, the Internet is already commonly used in transferring multimedia information.　Furthermore, with the rapid growth of electronic commerce, most multimedia materials are stored and transferred digitally. In an open cyberspace, ensuring the safeness of digital images is now an urgent need. Because every kind of multimedia files, such as sounds, images, movies (ex. VCD, DVD,) and audios (ex. MP3,) can be easily accessed, exchanged, duplicated, and transferred, protecting the intellectual property rights of digital multimedia information is getting more and more important. In the past, there have been plenty of studies about embedded digital watermarks , however, most of their methodologies were focused on grayscale digital files and pictures. On the other hand, this research is aimed at dealing with colorful pictures, based on the RGB color model, using the method of equally distributing visual information within the original areas of pictures, and utilizing the discrete wavelet transform to find the sub-band. Laboratory tests have proven that the effect of embedding watermarks in LL2 band is the most robust. After the watermarked information being encrypted, suitably extended, and with adjustment of the embedding factor, embedded in the band of the third level discrete wavelet transform, the purpose of hiding information can be achieved. Drawn-out watermarks can be re revamped and recalculated to improve the similarity of watermarks. Watermarks here have features of imperceptibility, transparency, robustness and security to successfully protect the intellectual property rights of digital colorful pictures within e-commerce on the Internet.

並列關鍵字

Watermark ； DWT (discrete wavelet transform) ； E-commerce ； Color Model

參考文獻

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