Image Encryption-Then-Compression System Operated in the Prediction Error Domain and Random Permutation

In many practical scenarios, image encryption has to be conducted prior to image compression. This has led to problem of how to design a pair of image encryption and compression algorithms such that compressing the encrypted images can still be efficiently performed. In this paper, we design highly efficient image encryption-then-compression (ETC) system, where both the lossy and lossless compression are considered. The proposed image encryption technique operated in the prediction error domain is shown to be able to provide high level of security. In this paper wealso demonstrate that an arithmetic coding-based approach can be exploited to efficiently compress the encrypted images. The proposed compression approach applied to encrypted images is only slightly worse, in terms of the compression efficiency, than the state-of-the-art loosely/lossless image coders, which take original, unencrypted images as inputs. In contrast, most of existing ETC solutions induce significant penalty on the compression efficiency.