Content modification using compressive sensing and double random phase encoding.

The encryption strength and compression efficiency are sometimes two opposing concepts in simultaneous picture compression and encryption methods. In this research, we suggest a novel lossy JPEG-based combined picture compression and encryption strategy that strives to increase encryption capability while preserving JPEG's compression efficiency. A covert orthogonal transform encrypts an original picture as a collection of coefficients. Since the image has a sparse representation in the conventional transform domain, it can be reconstructed from a small number of measurements, and thus allows the encrypted picture data to be compressed into a collection of measurement data. A secondary encryption approach based on the Fourier transform is used to a series of photographs to further strengthen their security. In addition, a fractional-order chaotic system with more complex chaotic behavior is constructed for application in picture compression and encryption. From what we can tell from experiments, the algorithm is robust and secure. First, we employ content-adaptive interpolation to acquire missing bitplanes and rejected pixels in order to rebuild the original picture. The first three MSBs are recovered losslessly by a combination of LDPC decoding, decryption, and Markov random field (MRF) exploitation. [ABSTRACT FROM AUTHOR]