Fast watermark detection scheme for camera-equipped cellular phone

Abstract

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.