Research On The Watermarking Algorithms For Digital Images

The watermarking techniques for digital images is a recently new techniques in the domain of research work in the world,which pertains to the solution for multimedia information security problem on network.It embeds watermarks into the digital images,then carries out the functions such as informations hiding,storing,copyright safeguarding by tracking the use of the image by detecting the watermarks.Hitherto,there are a quite few study institutions on it in China and in the world,but it is primary research phase and not really used.So the watermarking techniques for digital images has enormous potentials and immense space of application and development.The paper takes still images as example,firstly researches the major problems of watermarking techniques for digital images,especially have a discussion on typical algorithms and the characteristicness of Human Visual System, makes analysis on the watermark for the embedded places and the embedded strong and capacity etc.It innovates two different watermark schemes for digital images based on spatial or frequency domain.In the first scheme,it makes watermark to use chao sequences.one of chao sequences is used for watermark hiding,the other one is used for making watermark embedded into original image.Watermark embedded in principle must relate to chao sequences.When a bit in chao sequences is equal to 1,hiding watermark information of the corresponding bit is embedded into second Least Significant Bite.When a bit in chao sequences is equal to 0,hiding watermark information of the corresponding bit is embedded into Least Significant Bite.This paper brings forward a good manner by many tests.The second new scheme is a adaptive watermarking techniques for digital images based on DCT domain.It makes general analysis and research on DCT domain by the characteristicness of Human Visual System.Not only gives a permuting algorithms on digital image permuting and gives the manners of adaptive choice such as the embedded places,the embedded strong,the embedded capacity,but also brings forward some adaptive algorithms on watermark embedded and watermark decomposition.The final watermark image is made a similarity check against the original image.The results of computer simulation show that the proposed watermarking algorithms satisfy the requirements of robustness and transparency,and make foundation for the future research on the digital images watermarking techniques.The paper makes beneficial explore and research in the digital images watermarking techniques,which will promote development of digital watermark in a certain.