| Digital watermarking technology is very important in the field of information security.However,the original digital watermarking technology will cause irreversible deformation of the original carrier.In addition,JPEG image as a compressed format image,it has a characteristics of wide range of applications and fast transmission speed,so the JPEG image as a carrier of reversible watermarking technology research is very valuable.This paper investigated JPEG image reversible watermarking technology,summarized the development status of JPEG image reversible watermarking technology,aimed at the existing difficult problems of JPEG image reversible watermarking technology,analyzed some existing algorithm vulnerabilities,and further proposed three different JPEG image reversible watermarking algorithm.The details are as follows:(1)Proposed a reversible JPEG image watermarking algorithm based on DCT ac coefficient.The algorithm uses the quantized DCT dc coefficient and zero ac coefficient to measure the smoothness of the image block,and embedded the information in the image block with high smoothness is preferred to reduce the distortion.The watermark information is embedded in the quantized DCT ac coefficient of+/-1 successively.The experimental results show that the proposed algorithm causes little image distortion and has little effect on the size of file storage space.(2)Proposed a reversible JPEG image watermarking algorithm based on adaptive coefficient selection.The algorithm puts a kind of adaptive DCT coefficient in the forward using selection algorithm,and after using the quantitative measure the local complexity of image block DCT dc coefficients.Sorting the image block according to the local complexity,then use the frequency to divide the quantified DCT ac coefficients into 63 groups,separately generated 63 histograms.Then using rate of distortion model respectively to calculate the best embedded DCT coefficient of each histogram,embedding information in each histogram with minimal distortion,reduce the distortion at the same time increase the embedding capacity.However,each histogram embedding information brings different distortion,so the embedding efficiency function is used to measure the histogram embedding distortion,and the information embed in the histogram with small embedding distortion in priority.Experimental results show that the proposed algorithm has high embedding capacity and small distortion.(3)Proposed a robust reversible JPEG image watermarking algorithm to react against compression.The quantized dc coefficients are predicted by the Rhombus prediction pattern and the prediction error histogram is generated.The watermark information is embedded in the quantized dc coefficient by histogram shift technique.Since the quantized dc coefficient is less affected by JPEG compression,the algorithm can resist a certain extent compression attack.The experimental results show that the proposed algorithm can achieve reversibility and robustness under a certain degree of JPEG compression under low embedding capacity and relatively small image distortion. |
