The Research Of Jpeg Blind Watermarking Based On Embedded System

Digital watermarking is one of important ways to solve the digital multimediaauthentication, it is one of effective complement means of traditional encryption and becomesan important research in the field of information security. Digital watermarking technologyrefers to embed the hidden information into digital multimedia works embedded hiddeninformation in digital multimedia works can be extracted through only the dedicated detector.With the popularization of embedded devices, they will face nodes and image forgery attacks.When image data are sent by wirless network, image watermarking can certificate nodes anddata source on the embedded system. This thesis researches based on embedded system ofJPEG blind digital watermarking, the major work can be summarized as following:A blind digital watermarking algorithm of JPEG based on embedded system is proposedfor solving the problems of authentication and mass data transmission on the embeddedmonitoring system. The steps of inserting watermarking are: Firstly, watermarking image isscrambled by Anorld’s transform; Secondely, host image is devided into non-overlap datablocks; Thirdly, blocks data are executed pseudo three-dimension DCT, and insertedwatermarking by QIM, and execute inverse one-deminsion DCT; Finally, blocks data arequantizated and enthropy coded to be JPEG data. The steps of extracting watermarking are:Firstly, JPEG data are entropy decoded and inverse quantizated; Secondly, blocks data areexecuted inverse one-dimension DCT and extracted watermarking by QIM extractingcalculation; Thirdly, the extracted watermarking is conducted periodically Arnold’s transform.This algorithm combines JPEG with QIM and DCT to strengthen its invisibility androbustness.The proposed algorithm is transplanted on ARM11embedded system that uses linuxoperating system. Camera acquisites image data by v4l2technique, and are inserted watermarking by proposed algorithm to be JPEG format data that are sent to computer viawireless network. The JPEG data can be extracted watermarking and converted into AVIvideo on computer, and checked the true of source of data. Practical application testifys thatthe proposed algorithm is good for the performance of all resistance gaussian noise, salt noise,cropping attack, filtering attacks although it is not excellen for the performance of resistancespinning attack.