01557nas a2200193 4500000000100000000000100001008004100002260000900043653002800052653003200080653003200112653001700144100001500161700002000176245005500196300001200251490000700263520109300270 2004 d c200410aBlock Truncation Coding10aCopyright Protection Scheme10aIntellectual Property Right10aWatermarking1 aShu-Fen Tu1 aChing-Sheng Hsu00aA BTC-Based Watermarking Scheme for Digital Images a216-2280 v153 a

This article presents a novel watermarking scheme for digital images based on Block Truncation Coding (BTC). Unlike other watermarking schemes, the proposed method does not alter the original image during the process of watermark casting. Instead, an ownership share is constructed as a key to reveal the watermark without resorting to the original image. Moreover, it is possible to register multiple watermarks for a single host image in the proposed scheme. During watermark casting, the feature of the host image, which is extracted by means of BTC, is combined with the watermark to generate an ownership share. When revealing the watermark, the author can address his/her ownership share to extract the watermark. Even though the host image has been attacked, the extracted watermark is still perceivable. Altogether, the method has many other applications besides copyright protection. For example, it can be used to cover the transmission of confidential images. The experimental results of this study show the robustness of the novel scheme against several common attacks.