Research On Reversible Data Hiding Scheme Based On Digital Image

With the rapid development of information technology, the importance of information security became more and more important. Reversible information hiding is an important branch of information hiding,which played important role in medical, military, legal and other sensitive data field,and reversible data hiding sheme based on digital image draws our country and the attention of scholars at home and abroad. Reversible data hiding sheme embed secret information by modifing digital image, the image can be recovered completely in information extraction process. At present the domestic and foreign scholars have put forward a lot of reversible information hiding algorithm, this paper aims to improving and innovating their algorithm, all of this is to improve the hiding capacity of image and ensure the quality of secret image.The research mainly covers following 3 sections:1. Reversible information hiding algorithm based on difference of adjacent pixels. The algorithm is based on the image blocks, which scanning the image blocks by difference scanning order, and calculate the difference value of calculate pixels in sanning process. Draw the histograms of difference value of difference scanning order, select the histogram that has largest number of peak and pixel distribution is more concentrated. Then insert the secret data by selected histogram using the classic histogram shifting algorithm. The experimental results show that the algorithm can greatly improve the hiding capacity, at the same time, the secret image is embedded information can obtain higher image quality due to the use of different scanning sequence.2. Reversible information hiding algorithm based on edge of the prediction error. The algorithm used four directions of adjacent reference pixel to calculate prediction pixels of each embedded pixel value, then calculate the D-value between prediction value and original pixel. Setting the threshold for positive and negative prediction error for screening, select the embedded pixel according with the embedded conditions and insert the secret bit into cover image by expanding the prediction error. The experimental results show that the algorithm not only can get larger embedding capacity but also obtain smaller distortion.3. Reversible information hiding algorithm based on interpolation and difference expansion. The algorithm divides the cover image into two categories, reference pixel and the embedded pixel. Predicted values were average value of the reference pixels which around the embeddable computed by using traditional bilinear interpolation method. secret information is embedded with the interpolation pixel difference expansion. For large capacity of secret information we set a threshold value to screen reference pixels and embed the secret information to reference pixels. The results of experimental show that this algorithm compared with the previous difference expansion method can greatly improve the hiding capacity and stego image quality.