基於秘密分享與小波轉換之彩色影像浮水印機制

A Color Image Watermarking Scheme Based on Secret Sharing and Wavelet Transform

簡智傑(Jh-Jie Jian)

指導教授 ： 謝尚琳

大同大學/電機資訊學院/資訊工程學系所/碩士(2006年)

摘要

這篇論文提出一種使用影像秘密分享、離散小波轉換和JND模型的彩色影像著作權保護機制，這個機制共包含兩個部份:浮水印嵌入及浮水印取回。在浮水印嵌入部份，首先將彩色影像經過取樣產生特徵平面，再透過離散小波轉換取出影像的特徵，並將取出的特徵和人眼可辦識的圖像浮水印透過影像秘密分享來產生分享影像，再利用JND模型及離散小波轉換將分享影像嵌入原圖之中。在浮水印取回部份，首先從待測的彩色影像中取出分享影像，再從待測的彩色影像經過取樣產生特徵平面，之後再取出待測影像的特徵，接著和分享影像結合來取回浮水印，最後將所取回的浮水印與原始浮水印做比較來驗證是否侵犯著作權。
從實驗中顯示這個機制可以抵抗下列7種影像處理: 裁剪、模糊化、銳利化、縮小、JPEG失真壓縮、亮度調整和對比調整。

關鍵字

秘密分享 ； 浮水印 ； 彩色

並列摘要

This thesis proposes a copyright protection scheme for color images using image secret sharing, Just-Noticeable-Distortion (JND) model and wavelet transform. The scheme contains two phases: the watermark embedding phase and the watermark extracting phase. In the watermark embedding phase, the color space of the color host image is first converted from RGB to YCbCr. Then a special sampling plane is created from the YCbCr color space. Next, the discrete wavelet transform is used to extract the features from the sampling plane. Then, a principal share image is generated according to the features and the watermark. Finally, the JND value and the discrete wavelet transform are used to embed the principal share image in the color host image to generate the watermarked image. In the watermark extracting phase, the principal share image is first retrieved from the suspect image. Then, an expanded watermark is reconstructed using the features of the suspect image features and the retrieved principal share image. Finally, the recovered watermark is obtained after the reduction of the expanded watermark. The recovered watermark is then verified against the original watermark to examine the copyright.
The experimental results show that the proposed scheme can resist several attacks such as cropping, blurring, sharpening, scaling, JPEG compression, brightness adjustment and contrast adjustment.

並列關鍵字

Watermark ； JND ； color image

參考文獻

[1] Shang-Lin Hsieh and Bin-Yuan Huang, "A Copyright Protection Scheme for Gray-Level Images Based on Image Secret Sharing and Wavelet Transformation," Proceedings of International Computer Symposium, Dec. 2004.

[2] Shang-Lin Hsieh, Lung-Yao Hsu and I-Ju Tsai, "A Copyright Protection Scheme for Color Images Using Secret Sharing and Wavelet Transform," World Enformatika Society Krakow, ISBN 975-98458-9-X ,Poland, Vol. 10, Dec. 2005.

[3] Shang-Lin Hsieh and Lung-Yao Hsu, "A Copyright Protection Scheme for Color Images Using Secret Sharing and Wavelet Transform," Master Thesis, Tatung University, July 2005.

[4] C.C. Chang and J. C. Chuang, "An Image Intellectual Property Protection Scheme for Gray-Level Images Using Visual Secret Sharing Strategy," Pattern Reconition Letters, Vol. 23, pp. 931 - 941, June 2002.

[5] San-Hwa Wu and Hsiu-Feng Lin, "A Non-Embedded Watermarking Scheme for Non-Distortion Digital Product Copyright Verification," Master Thesis, Feng Chia University, Aug. 2004.