基于骑士巡游的灰度图象加密压缩算法

为了进一步提高涉密图像的存储和传输效率，提出了基于骑士巡游的灰度图像加密压缩算法。该算法将原始图像进行8×8分块，对每个块进行DCT变换，构建以块为单位的系数块化矩阵，然后采用骑士巡游置乱对该系数块化矩阵加密,对置乱加密后图像进行JPEG压缩得到加密压缩图像。实验仿真和分析表明,该算法密钥空间大、密钥敏感性高,在保证一定置乱度的前提下，获得了更高的压缩效率。

An Algorithm of Gray Image Encryption and Compression based on Knight's Tour

In order to improve the storage and transmission efficiency to transmit confidential images, an algorithm of gray image encryption and compression based on knight's tour is proposed. In this algorithm original image is divided in blocks of 8×8, then every block is transformed by DCT to build coefficient blocking matrix, afterwards the coefficient blocking matrix is scrambled by the knight's tour to get encrypted image, the encrypted compressed image could be gained after JPEG compression. The experimental results and analysis show that the algorithm has good effects such as the huge key space and the strong sensitivity, it get higher compression efficiency in premise of some degree of scrambling.