Prediction Error Based Compression of Encrypted Images
Ankita Vaish, Manoj Kumar · 2015
This paper presents, an efficient scheme for compression of encrypted images. In which, encryption is performed by decomposing the image into sub-images. For encryption, out of these sub-images a sub-image is encrypted using pseudorandom numbers which are derived from a secret key while for the other sub-images at first, prediction error is calculated and each of the prediction errors are encrypted using pseudo random permutation. For compression, pseudo randomly encrypted sub-image and each of the permuted prediction errors are compressed independently using quantization and Huffman coding technique respectively. At the receiver side, with the help of compressed data and secret key, a reliable decompression and decryption scheme is used in a joint way to reconstruct the original image content. To give the evidence of our findings, the proposed scheme is compared with an existing scheme and achieved better compression performance with improved image quality.