Study On Reversible Data Hiding And Its Application In Medical Image

Reversible data hiding technology can not only extract the embedding secretinformation, but also restore the original cover image, so the reversible data hiding schemehas become popular in last few years. Reversible data hiding technology is applied inmedical image, which can ensure medical image diagnosis and the patient data does notdisorder, can used to the integrity of the certification of medical image, In this paper,reversible information hiding are mainly studied theoretically and experimentally, themain work of the paper is as follows:This paper compared the advantage and disadvantage the two basic methods ofhistogram modification and difference expansion. Summary and Analysis on theimprovement scheme on histogram modification reversible data hiding method: gettingtwo peak points in the data hiding to hide more information; In the scheme of histogrammodification based on difference, setting infinity as zero point to decrease the length ofextra information; making multi-level hide to make sure hiding points are fully used.In the research of frequency domain and transformation, the way of transformationwhich is often used in picture is summarize in this article. By doing the research of thesome lossless information hiding, a mathematic model of data embedding is made to dofurther research. Then, the rule is work out, which the transformation matrix must obey inthe reversible information hiding. It is to let the reverse transformation matrix to be integeror part of it is integer.In this article, some experiments in which the medical images is used as the coverimage is also made to compare hide capacity of the data hiding scheme of Haar discretewavelet transformation and CDF(2,2) transformation. Then, the more simple improvedmethods of CDF(2,2) is proposed. To combine the transformation and embeddingtechnology, the improved CDF(2,2) is used to change a picture from special domain tofrequency domain and the data is embedded in the high frequency band by using theimproved histogram modification method.