Modified computational integral imaging-based double image encryption using fractional Fourier transform

• Double image encoding using computational integral imaging and FrFT.
• Proposed scheme provides high resolution due to the modified CII algorithm.
• Our method provides a high degree of security because of the multiple key spaces.
• The hologram-like property of EIA provides high robustness and security.

In this paper, we propose an image encryption technique to simultaneously encrypt double or multiple images into one encrypted image using computational integral imaging (CII) and fractional Fourier transform (FrFT). In the encryption, each of the input plane images are located at different positions along a pickup plane, and simultaneously recorded in the form of an elemental image array (EIA) through a lenslet array. The recorded EIA to be encrypted is multiplied by FrFT with two different fractional orders. In order to mitigate the drawbacks of occlusion noise in computational integral imaging reconstruction (CIIR), the plane images can be reconstructed using a modified CIIR technique. To further improve the solution of the reconstructed plane images, a block matching algorithm is also introduced. Numerical simulation results verify the feasibility and effectiveness of the proposed method.