Abstract: Two image scrambling algorithms are proposed based on Hilbert curve and Gray code that realize to any rectangular color image’s encryption.The first algorithm is aimed at the space scrambling of pixels，and the other is aimed at the pixels’24 bit which is correspond with R，G and B vectors.Decryption process is the inverse of the encryption.Experimental result proves that the new algorithm has a higher efficiency and reduces the relationship of pixels，especially the second algorithm，it has a higher degree of image scrambling.

摘要： 基于Hilbert曲线与Gray码，提出两种针对任意矩形彩色图像的加密算法，其一是对图像像素点的空域置乱，其二是对像素点的24位R、G、B分量的空域置乱，解密过程即加密过程的逆。实验证明，提出的算法具有更高的执行效率，并能更好地降低像素之间的相关性，尤其是后一种算法，具有非常高的图像置乱度。