Analysis and Comparison of Typical Reversible Watermarking Methods Yongjian Hu 1,2 , Byeungwoo Jeon 1 , Zhiquan Lin 2 , and Hui Yang 2 1 School of Information and Communication Engineering Sungkyunkwan University, Suwon Gyeonggi-do 440-746, Korea bjeon@yurim.skku.ac.kr 2 College of Automation Science and Engineering South China University of Technology, Guangzhou 510641, PRC eeyjhu@scut.edu.cn Abstract. In sensitive imagery, such as deep space exploration, mili- tary reconnaissance and medical diagnosis, traditional watermarks can be hardly found useful. The main reason is that the users are too worried about the loss of original information after the image being embedded with other data. Although early watermarking methods only distort the host signal imperceptibly, there is still some host information that may be permanently (irreversibly) lost. To avoid this disadvantage, some re- searchers (e.g. [1]-[3]) proposed the concept of reversible (lossless) water- mark. Recently, more and more reversible watermarking methods have been proposed. However, the influence of [1]-[3] is obvious. In this paper, we focus on analyzing and comparing these three reversible watermarking methods. Our investigation covers several aspects including data hiding capacity, image quality, capacity resilience and control, computational complexity, security, and blind data extraction. Such analysis and com- parison provide indispensable information for the design of new reversible watermarking techniques. Keywords: reversible watermarking, lossless watermark, data hiding, data compression. 1 Introduction Traditional watermarking methods accomplish watermark insertion into the host signal by sacrificing imperceptible host information. For example, one can replace the LSB (least significant bit) plane of the host image with a fragile watermark [4]. But such a strategy is not suitable for some new application scenarios like remote sensing, military imagery and medical diagnosis, where authentication or data integrity verification is only allowed under the condition that no host information is permanently distorted. As a solution to this problem, some researchers proposed the concept of reversible (lossless) watermark (e.g. [1]-[3]). However, as pointed out in [1], invertible authentication is not possible if we insist that all images, including “random” images, be authenticable. A real random image can not accommo- Y.Q. Shi and B. Jeon (Eds.): IWDW 2006, LNCS 4283, pp. 333–347, 2006. c  Springer-Verlag Berlin Heidelberg 2006