Validating the existence of watermarks on digital images using a mobile phone

The use of digital watermark in mobile platforms has been recently considered. This paper presents an strategy for watermark detection on digital images using a mobile phone. In the proposed scheme a digital watermark is inserted into an image and can be retrieved after a digital-analog (D/A) and analog-digital (A/D) conversion process. We propose the use of Neyman-Pearson criterion for the selection threshold, which consists in minimize the overall error probability, when the watermark is not actually present. In the proposed scheme, the digital watermark is embedded in the Discrete Fourier Transform (DFT) domain. Results obtained through abundant experiments show the effectiveness of the proposed approach.