Algorithm

Chaotic

Image compression

Materials science

Chaotic systems

Encryption

Image processing

Operating system

Computer science

Fractional Fourier transform

Wavelet transform

Discrete wavelet transform

Discrete cosine transform

Mathematics

Image (mathematics)

Fourier analysis

Mathematical analysis

Artificial intelligence

Composite material

Data compression

Compression (physics)

Fourier transform

Transform coding

Wavelet

Optics & Laser Technology

Based on hyper-chaotic system and discrete fractional random transform, an image compression-encryption algorithm is designed. The original image is first transformed into a spectrum by the discrete cosine transform and the resulting spectrum is compressed according to the method of spectrum cutting. The random matrix of the discrete fractional random transform is controlled by a chaotic sequence originated from the high dimensional hyper-chaotic system. Then the compressed spectrum is encrypted by the discrete fractional random transform. The order of DFrRT and the parameters of the hyper-chaotic system are the main keys of this image compression and encryption algorithm. The proposed algorithm can compress and encrypt image signal, especially can encrypt multiple images once. To achieve the compression of multiple images, the images are transformed into spectra by the discrete cosine transform, and then the spectra are incised and spliced into a composite spectrum by Zigzag scanning. Simulation results demonstrate that the proposed image compression and encryption algorithm is of high security and good compression performance.

Image compression-encryption algorithms by combining hyper-chaotic system with discrete fractional random transform