Colour image encryption using Gaussian apertured real-preserving fractional Mellin transform in diffraction domain

Abstract

A colour image encryption scheme based on Gaussian apertured real-preserving fractional Mellin transform (GARPFrMT) in diffraction domain and chaos permutation is proposed. Real-preserving fractional transform in diffraction domain using Gaussian aperture is constructed to ensure that the output is real, which is convenient for storage and communication. And the Gaussian aperture, as a soft aperture, can improve the intensity distributions of the output light, which contributes to prevent possible attacks for obtaining some useful information from the marginal leakage of light in the optical encryption systems. The colour space rotation transform is first used to convert the colour image from standard $RGB$ space to $R^{\mathrm{\prime }}{G}^{\mathrm{\prime }}{B}^{\mathrm{\prime }}$ space. And then, the three new colour components are transformed by GARPFrMT with three different diffraction channels, respectively. A 3D-logistic map is utilized to further scramble the three-colour components. At last, a logistic-sine map is used to perform Xor operation with three components, respectively. Simulation results demonstrate that the proposed algorithm is feasible and robust to noise attack and data loss.

KEYWORDS:

• Optical image encryption
• nonlinear GARPFrMT
• LCT
• 3D-logistic map
• Xor operation

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was partially financed by the National Natural Science Foundation of China [grant numbers 61861029 and 61662047], and Foundation of Jiujiang University [grant number 2015LGYB03].