A new low-resolution and robust digital watermarking technique for the personalization of travel documents
Alexander Herrigel, Slava Voloshynovskiy, Yuriy Rytsar · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2004
This paper presents a new approach for the protection of travel documents. We propose a digital watermarking technique which requires for the verification process a low scanning resolution of at least 72 DPI. The approach is based on the wavelet decomposition and supports three key aspects: Message encoding is accomplished by iterative error correction codes satisfying a nearly optimal channel capacity. This encoding is based on specific modulation that requires for the implementation a significant lower complexity as the often applied M-array modulation. The watermark embedding is applied in the wavelet domain based on stochastic driven perceptional criteria for a good quality and invisibility. The watermarking process is considered as a communication process with side information. The approach utilizes two different watermarks, one for the channel state information estimation and one for the informative watermark which carries as a payload the hidden information.