基植區塊式像素值差異法之多媒體隱藏研究

Blocked Pixel-Value Differencing to Secret Embedding in Multimedia Image Systems

楊政興(Cheng-Hsing Yang) ； 王旭正(Shiuh-Jeng Wang) ； 翁麒耀(Chi-Yao Weng) ； 孫宏民(Hung-Ming Sun)

《資訊管理學報》 15卷3期 (2008/07) Pp. 29-47

https://doi.org/10.6382/JIM.200807.0029

摘要

一個良好的藏密學技術必須是高容量以及偽裝後的影像不易被察覺。在2003年學者Wu et al.提出利用二個相鄰像素之間的像素值差異來隱藏資訊。本研究以四個相鄰的像素為一個區塊，利用像素的差異值來衡量區塊屬於邊緣區域或是平滑區域。如果區塊屬於邊緣區域，則可以容忍隱藏大量的資訊；反之，區塊屬於平滑區城，則可容忍隱藏較少的資訊量。區塊式像素值差異(Blocked Pixel-Value Differencing; Blocked PVD)的觀念為擴展學者Wu et al.提出的像素值差異(PVD)，將四個相鄰像素的差異值整體做考量，然後再劃分為二個群組，分別利用像素值差異法來隱藏資訊。另外，我們提出像素值移位的技術，讓嵌入的方法更具彈性。由實驗數據顯示，我們所提出的Blocked PVD方法，其資訊隱藏量比PVD方法還要多。

關鍵字

藏密學 ； 資訊隱藏 ； 像素值移位 ； 像素值差異

並列摘要

An efficient steganographic method usually provides a large embedding capacity and a small distortion for the stego-images. In 2003, Wu et al. proposed the pixel-value differencing (PVD) approach which applies the difference value of two consecutive pixels to data hiding. In this paper, we process a four-pixel block at a time, and use its difference value to judge that it is located in edged areas or smooth areas. If a block is located in edged areas, it may tolerate larger embedded information than those in smooth areas. Our blocked PVD approach is based on the PVD approach of Wu and Tsai. Each four-pixel block is divided into two two-pixel groups elaborately and each group is processed by the PVD approach. Moreover, an idea of pixel-value shifting is proposed in order to embed data more flexibly. Experimental results show that our method provides a larger embedding capacity than that of Wu and Tsai.

並列關鍵字

Steganography ； information hiding ； pixel-value shifting ； pixel-value differencing

參考文獻

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