利用行列变换的无损信息隐藏算法

为了充分挖掘载体图像的像素相关性，提出一种利用行列变换的无损信息隐藏算法LDHA RT。该算法依次计算列方向、行方向和对角线方向的像素差及其直方图，对获得的像素差直方图进行移位以构造冗余空间，实现在指定差值处嵌入隐藏信息。在提取隐藏信息后，LDHA RT算法可以无损地恢复载体图像，不需要除隐藏信息以外的附加信息。仿真实验表明，与参考文献的算法相比，LDHA RT算法的PSNR／bits是最低的或接近最低的，表明该算法在保证图像质量的情况下，具有隐藏信息容量大的优势。

Lossless data hiding with ranks transform

For taking full advantage of carrier image's pixel correlation, a lossless data hiding algorithm with ranks transform (LDHA_RT) is proposed. Along with three directions of column, row and diagonal, the pixel difference images and their histograms are calculated one after another. The obtained pixel difference histograms are shifted to construct the redundancy spaces, so that the hiding information could be embedded in a designated position. After the hiding data is extracted, the carrier image could be recovered reversibly without any additional information. The experiments demonstrate that the PSNR/bits of the LDHA_RT is the lowest or close to the lowest, compard with these algorithms mentioned in the references. This implies that the LDHA_RT has large capacity of hiding data under a good image quality.