Cosine Number Transform based hybrid image compression-encryption

A novel hybrid image compression-encryption based on Cosine Number Transform and measurement matrix is proposed. The Cosine Number Transform is defined over algebraic structures in a finite field. Therefore only modular arithmetic is needed for computing the transform. Simultaneous compression and encryption is achieved by using chaotic map based key in the generation of a measurement matrix. One dimensional logistic map is used to generate measurement matrix and to confuse and diffuse the compressed image. A block based compressive sampling technique is used which reduces computational complexity and memory requirements. Simulation results demonstrate that the cipher image has low data volume and robustness against various attacks.