In this paper, a digital watermarking technique for image annotation has been applied for the purpose of turning a conventional printed medium into a hypermedia. By exploiting redundancy available in photographic images, hyperlink information can be invisibly embedded. To achieve the goal as stated, a spread spectrum-based watermarking method with high embedding capacity has been developed for the task at hand. In addition, by choosing image part for watermark embedding based on its spatial-hyperlink relationship, embedding of 'image map' coordinates is not needed. Computer experiments have been carried out to evaluated the proposed concept and the developed spread spectrum-based watermarking method.
