A Novel Image Encryption Supported by Compression Using Multilevel Wavelet Transform

Abstract

In this paper we propose a novel approach for image encryption supported by lossy compression using multilevel wavelet transform. We first decompose the input image using multilevel 2-D wavelet transform, and thresholding is applied on the decomposed structure to get compressed image. Then we carry out encryption by decomposing the compressed image by multi-level 2-D Haar Wavelet Transform at the maximum allowed decomposition level. These results in the decomposition vector C and the corresponding bookkeeping matrix S. The decomposition vector C is reshaped into the size of the input image. The reshaped vector is rearranged by performing permutation to produce encrypted image. The vector C and the matrix S serve as key in the process of both encryption and decryption. In this analysis, we have noticed that the reconstructed image is a close replica of the input image.