基於JND模型與QR Code特性之數位浮水印

Digital Watermarking Based on JND Model and QR Code Features

董昌儒(Chang-Ru Dong)

指導教授 ： 李錫捷

元智大學/資訊學院/資訊管理學系/碩士(2012年)

摘要

在現代社會中，網路是不可或缺的工具，有越來越多的裝置都支援上網的功能如智慧型手機與平板電腦等，隨著資訊流動更加頻繁， QR Code（Quick Response Code）的興起使得資訊傳播更方便，近年來大幅使用QR code做為商業行銷或是行動服務的利器，隨著條碼的廣泛使用，它的價值也跟著與日俱增，但是也因為如此對於QR code安全性的潛在威脅就不能忽視，例如票券上使用QR code作為購票證明，單純的條碼容易修改或破壞，若是以可視浮水印的方式藏在圖示中，不僅可保持條碼的可讀性，也減少被發現和竄改的機會，再進一步以驗證機制來保證原有資訊的完整性。
　　研究中以JND Map(Just Noticeable Difference)為基礎並使用浮水印方式來將QR Code置入影像並調整至手持裝置可讀取的程度，再以離散餘弦轉換（Discrete Cosine Transform）方式嵌入數位浮水印以及加入驗證資訊用以檢測驗證圖像的完整性及有無遭竄改或破壞。

關鍵字

QR Code ； 最小可察覺差異 ； 離散餘弦轉換

並列摘要

In this study, we proposed a method to hide Quick Response Code (QR Code) into images; the method combines Just Noticeable Difference (JND) model and digital watermark techniques and consists of three parts. First, Using JND Model to find the JND map of images and using Sobel operation to find contour of images. Second, find the area there QR Code will embed by scanning the JND map and contour of images with the mask. Finally, in order to hide QR Codes in Images , we adjust the pixel value in the area QR Code embedded and add in invisible watermark by Discrete Cosine Transform (DCT) and verify information for security propose.

Experimental results showed that the proposed method performs better than the way that puts QR Code in the image without processing, we can not only hide QR Code into images but also the QR Code can be detected clearly.

並列關鍵字

QR Code ； JND ； DCT

參考文獻

[1] P. Kieseberg, M. Leithner, M. Mulazzani, L. Munroe, S. Schrittwieser, M. Sinha, and E. Weippl, "QR code security," presented at the Proceedings of the 8th International Conference on Advances in Mobile Computing and Multimedia, Paris, France, 2010.

[2] S. Ono and S. Nakayama, "A system for decorating QR code with facial image based on Interactive Evolutionary Computation and Case-Based Reasoning," in Nature and Biologically Inspired Computing (NaBIC), 2010 Second World Congress on, 2010, pp. 401-406.

[3] D. Samretwit and T. Wakahara, "Measurement of Reading Characteristics of Multiplexed Image in QR Code," in Intelligent Networking and Collaborative Systems (INCoS), 2011 Third International Conference on, 2011, pp. 552-557.

[4] H. C. Huang, F. C. Chang, and W. C. Fang, "Reversible data hiding with histogram-based difference expansion for QR code applications," Consumer Electronics, IEEE Transactions on, vol. 57, pp. 779-787, 2011.

[6] L. Li, R. Wang, and C. Chang, "A Digital Watermark Algorithm for QR Code," presented at the International Journal of Intelligent Information Processing, 2011.