基于最优DCT频段嵌入的JPEG图像可逆信息隐藏方法  

JPEG reversible data hiding method based on optimal DCT frequency embedding

作　　者：周子扬 谭云[1] 秦姣华[1] 向旭宇 ZHOU Ziyang;TAN Yun;QIN Jiaohua;XIANG Xuyu(Central South University of Forestry and Technology,Changsha 410004,China)

机构地区：[1]中南林业科技大学,湖南长沙410004

出　　处：《网络与信息安全学报》2023年第4期166-177,共12页Chinese Journal of Network and Information Security

基　　金：国家自然科学基金(62002392);湖南省自然科学基金(2020JJ4140,2020JJ4141,2022JJ31019)。

摘　　要：JPEG(joint photographic experts group)图像不仅能够保证良好的画质,且所需存储空间较小,是目前互联网应用最广泛的图像格式。JPEG图像可逆信息隐藏(RDH,reversible data hiding)方法可以隐藏和提取秘密信息,并无损恢复原始图像,被广泛用于文件管理和图像认证,具有非常重要的意义。现有的大多数RDH方法在嵌入秘密信息后会明显增加载密图像的存储空间,对基于离散余弦变换(DCT,discretecosine transform)系数嵌入的方法来说,如何选择频段位置是影响JPEG图像可逆信息隐藏性能的关键问题。提出一种基于最优DCT频段嵌入的JPEG图像可逆信息隐藏方法。将熵解码后的JPEG图像分割成大小为8×8非重叠的DCT块,计算每个DCT块的平均纹理复杂度并进行升序排序,并将相邻DCT块中相同频段的交流系数(AC,alternating current)进行两两配对,在满足待嵌入信息容量的条件下,根据AC系数频段的失真代价函数求出最优AC系数频段位置集合。根据所设计的二维直方图映射策略嵌入秘密信息。实验结果表明,与现有方法相比,所提方法不仅降低了载密图像文件存储大小的扩展,且载密图像能够保持良好的视觉质量。Joint photographic experts group(JPEG)images are widely used on the Internet due to their ability to maintain good picture quality while requiring less storage space.Reversible data hiding(RDH)techniques for JPEG images enable the hiding and extraction of secret information while allowing for lossless restoration of the original image.RDH is of great significance in file management and image authentication.However,many existing RDH methods result in a significant increase in the storage space of the encoded image after embedding secret information.For methods based on discrete cosine transform (DCT) coefficient embedding, the key issue that affects theperformance of reversible information hiding in JPEG images is how to select the frequency band position. Areversible information hiding method for JPEG images was proposed, based on optimal DCT frequency embedding.The entropy decoded JPEG image was divided into 8×8 non-overlapping DCT blocks. The average texture complexityof each DCT block was calculated and ordered in ascending order. Then the alternating current (AC) in adjacent DCTblocks was paired pairwise. By satisfying the capacity of the information to be embedded, the optimal AC coefficientfrequency position set was obtained from the distortion cost function of the AC coefficient frequency. The secretinformation was embedded according to the designed two-dimensional histogram mapping strategy. Experimentalresults demonstrate that the proposed method can reduce the expansion of the loaded image file’s storage sizecompared to existing methods, while maintaining good visual quality of the cover image.

关 键 词：JPEG图像 可逆信息隐藏 二维直方图 平均纹理复杂度 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]