Research On Adaptive Reversible Digital Image Watermarking Algorithm

With the continuous development of science and technology,the popularization of digital multimedia information has brought great convenience to people's lives,but at the same time also brought some challenges.For some criminals can easily get these digital multimedia information after the tampering release,has brought a series of problems of information security issues.Digital watermarking is a way to solve the related security problem.By embedding the containing the information of watermark to the relevant digital product,the legitimate user can extract the useful watermark to prove the relevant rights and interests of the user.Traditional digital watermarking technology to extract the embedded watermark will cause irreversible distortion of the original multimedia information,is not suitable the areas with higher quality requirements for original multimedia information,in order to overcome the traditional digital watermark shortcomings that reversible digital watermark emerges,Reversible digital watermarking refers to the extraction of embedded watermark,but also can completely to restore the original multimedia information without distortion.In this paper,the image is used as the original carrier of the reversible digital image watermarking technology,when using different embedded watermark capacity,the improved correlation algorithm makes the embedded watermark image quality can be improved.he main contents and innovations of the paper are as follows:(1)This paper introduces the development and application of reversible digital watermarking technology,and studies the current mainstream reversible digital watermarking algorithm,and analyzes the basic principles and implementation process of different algorithms.Using MATLAB to build the experimental platform,the experimental platform can be used to simulate the algorithm.(2)In order to solve the shortcomings of prediction error method in prediction accuracy and image imperceptibility,an adaptive selection block reversible image watermarking based on pixel sort prediction is proposed.Firstly,the original image is divided into blocks,and then the image sub block noise level is calculated by the gradient between the pixels and the average value,and combined with the pixel sort prediction operator to obtain the prediction error histogram;Finally,the predictive error histogram is used to adaptively select the appropriate location to embed the watermark.The algorithm can improve the predictive accuracy of the predictor.The adaptive selection image sub-block embeds the watermark so that the image distortion is reduced after embedding the watermark.(3)In order to solve the contradiction between the concealment of watermarked image and embedded watermark information capacity.A reversible image watermarking algorithm with adaptive two-pass on prediction distortion embedding was proposed.Firstly,the images is divided into blocks,the texture complexity of the sub-blocks is measured by variance.and the initial value of sub-block embedding intensity is set according to the texture complexity.and then dynamivally adjust the embedded intensity by sub-block prediction distortion.Finally,embedded watermarking is carried out by embedding intensity adaptive two-pass.The propose method can reduce image distortion effectively in high capacity embedding.A high capacity and high quality image reversible watermarking algorithm is implemented.