Color image encryption using double random phase encoding

Abstract

A new encryption technique is proposed to encrypt color images using existing optical encryption systems for gray‐scale images. The color images are converted to their indexed image formats before they are encoded. At the decryption end, the color images are recovered by converting the decrypted indexed images back to their RGB formats. The proposed single‐channel color image encryption method is more compact and robust than the multichannels methods. Since color information is added to the shape information, better verification performance can be achieved in optical security systems. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 21: 318–323, 1999.

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

“…Since in many cases, color image provides more information than monochromatic one and to some extent, the color information can give more security level than the binary and gray images, therefore, in the past decade, many optical techniques and applications for the color image processing have been proposed and developed gradually [21][22][23][24]. In general, the most common method proposed for color information processing is the multichannel decomposition based on the RGB theory, however, the complexity and cost will be increased due to the multichannel representation of color image when it is achieved by optical means [22,23].…”

“…In general, the most common method proposed for color information processing is the multichannel decomposition based on the RGB theory, however, the complexity and cost will be increased due to the multichannel representation of color image when it is achieved by optical means [22,23]. Another common approach is single-channel optical realization based on digital transformation of the color image to indexed type [21], which is more compact and reliable when comparing with multichannel ones. Recently, parallel phase-shifting digital holography technology [25,26] is proposed which can be used to realize the color image hybrid recording.…”

“…There are a number of related security systems for color image processing having been done. It shows that since more information is contained in a single color image than the gray or binary one, to realize the multiple color images security will be even more complicated than other methods [11,12,14,[16][17][18][19][20][21][22][23][24]. In order to promote the system performance for color image processing, digital means should be used as an assistant way for their potential value in many occasions [16][17][18][19][20][21][22][23][24][25][26].…”

Optical color image encryption with redefined fractional Hartley transform

“…In many cases, we need the color information not only for its beauty in vision but also for the meaningful practical use. In 1999, Zhang and Karim introduced a color image encryption method on the basis of FT [15]. Later, a new real color fractional FT has been presented by Jin et al [16].…”

Color image single-channel encryption based on tricolor grating theory

“…More and more people have been attracted in this domain and some optical methods have been proposed in this area. Zhang and Karim introduced a method for color image encryption based on Fourier transform [7] . Zhao and Chen presented a multichannel color image encryption method by wavelength multiplexing based on lensless Fresnel transform holograms and double random phase encryption [8,9] .…”