The Research Base On DFT And Digital Watermarking Technologies For Characteristic Of Images

With the development of computer and network, digital media can be spread and copied easily. At the same time, digital copyright protection has become a serious problem. Watermarking is considered as a new means to solve this problem. Information is embedded to host media to protect the integrity and the ownership.Based on analysing the characteristics and demand of the information hiding technology,this article propose a kind of images digital watermarking algorithm based on the wavelet domain transformation and a meaning watermark algorithm based on DFT。This thesis providing a meaning watermark algorithm based on DFT。(1)In order to enhance the security, the watermark data was scrammed with Arnold transform before embedding.(2)For increasing the accurate rate of the traditional relativity examination method,embeding watermark adopt embeding two not related. (3) Because the low frequency coefficients contains the most of the energy, the modification causes to distortion.So this thesis modify the high and the middle frequency part to embeding.(4) The examination method of this thesis is a blind examination in half Only part of the original watermark information is involved in watermark detection, so it has practical meanings.Based on separate wavelet transformation auto-adapted image numeral watermark inserting algorithm. This article algorithm mainly takes the instruction using the human eye visual attention mechanism, rests on inserts the watermark in the image characteristic Finally confirmed this article algorithm through the experimental method to have the strong robustness, moreover joined the watermark could not affect the image the visual quality, and could carry on the watermark effectively the extraction and the examination.