Pure optical dynamical color encryption

Abstract

We introduce a way to encrypt-decrypt a color dynamical phenomenon using a pure optical alternative. We split the three basic chromatic channels composing the input, and then each channel is processed through a 4f encoding method and a theta modulation applied to the each encrypted frame in every channel. All frames for a single channel are multiplexed. The same phase mask is used to encode all the information. Unlike the usual procedure we do not multiplex the three chromatic channels into a single encoding media, because we want to decrypt the information in real time. Then, we send to the decoding station the phase mask and the three packages each one containing the multiplexing of a single channel. The end user synchronizes and decodes the information contained in the separate channels. Finally, the decoding information is conveyed together to bring the decoded dynamical color phenomenon in real-time. We present material that supports our concepts.

Storage and reconstruction of multiple color images with a phase-only hologram

“…He et al realized the storage of four color images with an orthogonal composite grating [12]. Mosso et al introduced a pure optical dynamical color image encryption method to implement 30 color images at one time [13]. Obviously, the proposed techniques have limited storage capacity for color images.…”

A review of optical image encryption techniques

“…The Hartley transform (HT), which is effectively a real Fourier transform without any phase information, has also been proposed for the use in optical DRPE systems [41][42][43][44][45]. In addition, the DRPE has been investigated for use in multiple-image encryption [46][47][48] and color image encryption [49][50][51][52][53][54][55][56]. The image scrambling techniques, which can be viewed as computer based numerical preprocessing procedure, have also been applied in conjunction with theDRPE system using the Jigsaw transform (JT) [57][58][59] and the Arnold transform (ART) [60][61][62][63][64].…”

Optical field data compression by opto-digital means

“…This technique has given rise to the development of sophisticated opto-digital methods that profit from both the properties of optical systems and the flexibility of digital data processing algorithms. Among the applications of digital holography, we find metrology, microscopy, medical imaging, and optical security [1][2][3][4][5][6][7][8][9][10], to name a few. Specifically, digital holography allows for recording information from 2D and 3D objects [11,12], providing additional degrees of freedom for optical processing [13][14][15], and consequently making possible the reconstruction of scenes with depth [16].…”