Digital watermarking technology would be very useful as part of a related service introduction system (RSIS); this system provides related information to content, and the function of watermark in RSIS is analogous to that of barcode, i.e., watermark binds content ID to analog content such as an image on printed material.In this paper, we focus on a camera-equipped cellular phone used as a terminal for RSIS, and propose a fast watermark detection scheme from a captured image. The proposed scheme consists of two processes, one is to correct geometric distortion of the captured image, and the other is to detect watermark information from the rectified image. We also propose a new watermarking algorithm which is robust against small geometric distortion and suitable for the proposed scheme. Moreover, we introduce a quantitative evaluation method for indicating detection reliability, which is indispensable for RSIS service.Finally, we show that the proposed scheme enables users to detect embedded information in approximately one second, even when implemented as a Java application on a cell phone with limited resources, and report experiments that confirm the proposed scheme's efficiency.

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An improved scheme for integrity protection of binary images representing text documents based on the topologies of these images is proposed. The image skeleton and the inverse skeleton are found through thinning and the skeleton signature is combined with watermark information. The result is encrypted asymmetrically and hidden in embeddable locations of the image. A series of attack experiments are conducted to demonstrate that the approach is capable of detecting tampering. Even single malicious pixel modifications are detected. The approach has a lower computation cost than previous methods.

Digital watermarking technology can be applied to reference services that provide digital information related to pictures taken by mobile phone cameras. Conventional reference services for mobile phones are designed for still images and detect watermarks from single pictures. We propose a video watermarking scheme for fast, robust detection to develop a reference service for video. To handle spatial synchronization, the scheme uses the rectangular tracking technique, and to provide temporal synchronization and robustness against noise, it uses the watermark technique based on the SFPSS method. We also introduce a quantitative evaluation method to determine reliability of the detection results. Finally, we evaluate the scheme's implementation on a mobile phone and demonstrate its efficiency.