Multiple color images encryption by triplets recombination combining the phase retrieval technique and Arnold transform

Generalized Arnold map-based optical multiple color-image encoding in gyrator transform domain

“…Besides single-image optical encryption, researchers have developed multiple-image optical encryption as well [22][23][24][25][26][27][28][29][30][31][32]. The reported methods include wavelength multiplexing [22][23][24], position multiplexing [25,26], spread-space spread-spectrum technique [27] and frequency shifting [28].…”

“…Recently, in order to enhance the encryption efficiency, multipleimage optical encryption algorithms have been further developed [29][30][31][32]. In [29], a new spectral multiple image fusion analysis based on the discrete cosine transform (DCT) and a specific spectral filtering method has been reported in which each DCT is filtered with low-pass filter whose size is related to the number of target images.…”

“…In [30], a multiple-image encryption scheme using the phase retrieval process and phase mask multiplexing in the fractional Fourier transform domain has been suggested where the proposed phase retrieval process has high convergence speed, and the encryption algorithm can avoid cross-talk; in addition, its encrypted capacity is considerably enhanced. In [31], a multiple color image encryption has been introduced where each one of the secret color image is decomposed into R, G and B channels and recorded by the wavelength-filter as a hybrid gray image. Then the hybrid result is permutated by the Arnold transform and encrypted by the phase retrieval technique adapted to the Fresnel transform domain.…”