Research On Image Information Hiding In Wavelet Domain

Information hiding is a new technique for information security and multimedia signal processing, which embeds the cryptical information into the open media information forever to testify the ownership of the media information and integrality of the data, consequently offers a new resolvable method for digital information security.Based on gray images, firstly we gives a brief introduction about the basic knowledge of the information hiding technique, which mainly includes the types, principle, common algorithms and difference on cryptography of information hiding technique.Since image scrambling is the basic work for image information hiding problem. Firstly this paper introduces the characteristic of scrambling transform and the function in image information hiding, and then the paper introduces a typical scrambling transform-Arnold transform. Through calculating with matrix transform, we derived the algorithm of anti-Arnold transform and apply it to all kinds of image scrambling.Finally we testify the superiority of Arnold transform to the other scrambling transform with scrambling degree.We introduce in succession the wavelet transform and the application in image watermark, which lay the stability foundation for the following study.According to the data fusion technique, the last part of this paper gives a method that the two images' low frequency portions are divided into segments of the same size for the purpose of image information hiding. At first, the blocked low frequency segments are scrambled and encrypted, then the different scrambled segments are embedded with cryptical image information according to the difference of the image segments' energy. In conclusion, the robustness of the algorithm is improved with numerical experiments, the advantage and the disadvantage are found as well through the comparison of the experiment data.