The Research On Robust Digital Watermarking Technology Based On Digital Hologram

With the rapid development of multimedia and network technology, people can exchange, transmit and store a variety of digital products more easily. However, the easy copying of digital products, easy communication, easy forge, making copyright protection of digital products become increasingly seriously, it becomes a urgent problem need to be resolved. Digital watermarking is regarded as "the last line of defense" to against media piracy, so digital watermarking technology has a broad application prospect and great economic value.Digital watermarking technology is a new type of digital copyright protection technology, developed in recent years, for robust watermarking, required it to be able to resist various attacks. The digital watermark's structure and the embedding algorithm are the two aspects to impact robustness of digital watermarking,therefore in order to improve the robustness of the digital watermark need to study the two aspects.When the carrier image was attacked,the watermark would lost information or be interferenced easily, which led to the watermark information can not be identified. The hologram has the characteristics of the part information could reconstruction of the whole information and the strong anti-attack capability, so it's suitable for embedding the hologram of the watermark. When the important information of the hologram damaged such as cutting attack, resulting in ineffective reconstruction of the hologram by lossing too much information, a scramble method based on chaotic map sequence to scramble hologram has been proposed, which could greatly improved the effection of the reconstruction hologram. It would increase the robustness of digital watermarking.According to the requirement of robust digital watermarking, a digital watermark embedding scheme was proposed based on digital hologram and DWT-SVD. The scheme combines the characteristics of strong resistance to geometric attacks by SVD transform and the characteristics of resistance to noise, compression by DWT transform, large number of experiments show that the scheme has good robustness, which can against various attacks, especially in strong noise, strong compression attack.