Dynamic watermarking of images

With the rapid growth of networked multimedia data systems, copyright protection of proprietary digitized media has gained importance. Inserting a robust and invisible signal that clearly identifies the owner or the recipient is beginning to emerge as the solution. Previous research in the field of watermarking has been successful in inserting a ´static´ watermark, which endures ownership rights but is not as robust and tamper-proof as the ´dynamic´ watermarks. This paper presents a novel invisible and robust watermarking technique that aims at dynamically inserting the watermark in digital images. Dynamic generation of watermark ensures that whenever the image is viewed, the watermark inserted in the image is different from the previous one providing more security against copyright attacks. This is accomplished by bundling the viewer and the image together, in which the viewer is responsible for embedding the new watermark using the spread spectrum watermarking algorithm every time. We have implemented the proposed scheme and present experimental results.