Abstract: To ensure the security and robustness of hiding image information under the conditions of visibility, a digital image hiding method based on a chaotic system with variable parameters was proposed. Firstly, with the pseudo-random sequences generated by the chaos system, a hiding image was encrypted. Secondly, the one-dimensional vector which transformed from the template image was divided into a number of equal parts according to the size of the hiding image, and each part corresponding to each pixel of the hiding image. Finally, with the new chaotic sequences and digital image blending technique, the pixel of hiding image was blended into a position of the part. This digital image hiding technique improves the imperceptibility and security of hiding image. Simulation results show that the proposed technique has good imperceptibility and high robustness.

Key words: chaos sequence, image encryption, image blending, Piecewise Linear Chaotic Map （PLCM）

摘要： 在数字图像隐藏方案中，为了在保证隐藏信息不可见性的条件下，尽可能地提高隐藏图像信息的安全性与鲁棒性，提出一种基于变参数混沌系统与图像融合技术相结合的数字图像隐藏技术。首先，利用变参数混沌系统产生的混沌序列对待隐藏的秘密图像进行加密预处理；而后根据待隐藏图像的大小，把由模板图像按行转换成的一维向量分为若干等份，每一等份唯一对应于待隐藏图像的一个像素；最后，再次利用该混沌系统生成新的混沌序列来确定待隐藏图像的每个像素在每一等份中的位置,并结合图像融合技术把该像素隐藏在该等份的这个位置上。该算法保证了隐藏图像的安全性，提高了隐藏的视觉效果。实验结果证明，本算法具有很好的隐藏效果和较好的鲁棒性。

关键词: 混沌序列, 图像加密, 图像融合, 分段线性混沌映射