Researches Of Digital Watermarking Technology In Transfoming Region Based On Image Sub-Block

Digital watermarking is a new technology in information security, whose purpose is to protect the copyright of digital product. Generally, it can be classified in three parts: digital video watermarking, digital audio watermarking and digital image watermarking. Imperceptibility and robustness are its main characteristics. The high robustness is decided by the occasion used in, so it can guarantee the security of watermarks. Currently, image watermarking is discussed more frequently than the others, some reasons of which are the wide use of images. To image watermarking, imperceptibility means the invisibility of watermarks inserted, so the watermark is cryptic and at the same time the image product can be used normally; Robustness describes the ability to resist the outside attack. Although great progress has been made in digital watermarking, digital watermarking is theoretically weak. At present, the research is focused on the balance between invisibility and robustness. And robustness to the normal image processing is the main content in...