一种加密域可逆隐藏算法的分析及改进

Analysis and Improvement of a Reversible Hiding Algorithm in Encrypted Domain

分析指出一种加密域可逆信息隐藏算法不能实现无损恢复的原因——仅用四邻域预测像素类型.为实现原始图像的无损恢复,结合像素自身和四邻域来预测像素类型,利用类型标示矩阵记录像素的平滑性并将其压缩后隐藏在部分平滑像素中,接收者利用提取的类型标示矩阵与邻域像素可无损恢复原始图像.实验仿真结果表明,所提出的改进算法不仅能无损恢复原始图像,而且进一步提高了嵌入容量和解密图像的质量.

It is analyzed that the four-adjacent-pixel prediction reversible information hid-ing algorithm cannot achieve a lossless recovery from encrypted images. In order to achieve the errorless recovery of the original image, a new the pixel-type is proposed by combining four neighborhoods with pixel to be predicted itself, and compressing type-mark matrix, which is used to record the smoothness of the pixels, and embedding it into the smooth pixels. Accordingly, in the recovery phase, the original image can be recovered perfectly with the help of the extracted type-mark matrix and its neighbor pixels. Experimental results demonstrate that the proposed method can achieve real reversibility, and further improve the embedding capacity and the quality of decryption image.