Research On Digital Video Watermarking Technology Based On Spread Spectrum

With the development of society science and technology,digital video as well as digital audio,image and other multimedia products has been widely used,which makes digital watermarking method to solve the ownership problem become particularly important.Watermarking technique of digital multimedia products has become one of the hottest fields to be studied in recent years.This paper firstly makes a brief description about digital video watermarking technology based on spread spectrum.The basic principle of digital watermarking system is analyzed and the algorithm and scheme of video watermarking are analyzed.Since the videos which we usually see are the compression of videos,watermark embedding can be before compression and after compression.Take the convenience and practice into consideration,the adjustive digital video watermarking based on spread spectrum and the DCT domain based on spread spectrum are proposed and compared.The first scheme mainly scrambles the watermark signal which is spreaded and modulated with the generation of m sequence to get a random sequence.This scheme is established on image watermark embedding based on the classical algorithm by making the watermarking information embed into the DC coefficient of DCT in the I frame of the video stream.The second scheme considers the human characteristics and information in the intra and inter frame and classifies the video image block according to the motion information and regional complexity.This algorithm selects the I frame for watermarking embedding.We will take the watermark information modulated by m sequence into DCT DC coefficient of different blocks in I frame.Then,according to the real-time of video,adaptive watermark information is embedded.In the two schemes,this paper uses Matlab 7.1 simulation software to do some simulations about the quality of video quality and the effect of the extraction of the watermark by different attack intensities of watermarking.Finally,the four attack types including zoom in attack,zoom out attack,cropping attack and noise attack are simulated and analyzed and the experimental results are also discussed.