摘要
提出了一种基于计算全息和θ调制的彩色图像光学加密新方法.该方法利用彩色三基色原理和计算全息编码技术,首先将彩色图像的红、绿、蓝三基色分量进行随机相位调制和菲涅耳衍射变换,然后经过θ调制后进行图像叠加并编码为计算全息图,即加密过程是将一幅彩色图像加密为一幅实值的二元计算全息图,得到单幅密文.解密为加密的逆过程,首先将加密的计算全息图置于空间滤波和菲涅耳衍射系统中,经过相位密钥解调和基于滤光片的滤波器滤波,最后通过正确距离的菲涅耳衍射完成解密,得到彩色明文图像.计算机模拟结果证明了该方法的有效性和可行性.
In this paper, a new method of encrypting a color image based on θ modulation is proposed by using the tricolor principle and computer-generated hologram(CGH) technology. The encryption process includes the qmodulated three primary color components and the coding of computer-generated hologram, which is implemented in a Fresnel diffraction and spatial filtering system. Firstly, the color image modulated by the first random phase key is divided into three encryption channels by red laser, green laser, blue laser, and tricolor filters. Each channel is introduced by a transmissive amplitude-type sinusoidal grating with different directions,which is used to separate the three primary color components in the spatial spectrum plane. Secondly, the modulation results of tricolor components are superimposed together to form a compound image, and the phase truncation of the superposition result is performed to achieve the asymmetric encryption. Finally, the amplitude of the compound image is modulated by the second random phase key and is encoded into a binary real-value gray-color CGH by Roman-type coding method. Therefore, the gray-color information of the original image is completely hidden in the encrypted CGH, which is more general and deceptive in the storage and transmission process. Decryption is an inverse process of the encryption. Firstly, the encrypted CGH is placed on the input plane of the spatial filtering and Fresnel diffraction system. Secondly, the demodulation of CGH phase key and the spatial filtering based on optical filter are performed. Finally, the color plaintext image is obtained by using the correct Fresnel diffraction. The simulation results show the validity and feasibility of the proposed method.In addition, the anti-noise attack and anti-shearing attack performance of this color image encryption method are investigated. Compared with results from the three presented methods reported in the literature, our investigated results demonstrate that this method has good robustness to noise attack and shearing attack, and has obvious advantages when the attack noise density is larger. Due to the characteristics of high security and anti-noise, we believe that this color image encryption method promises to have important applications in the information transmission and multi-user authentication.
引文
[1]Refregier P,Javidi B 1995 Opt.Lett.20 767
[2]Liu Z,Chen H,Blondel W,Shen Z,Liu S 2018 Opt.Lasers Eng.105 1
[3]Chen L,Zhao D 2006 Opt.Express 14 8552
[4]Borujeni S E 2013 J.Telecommun.Syst.52 525
[5]Shi Y S,Li T,Wang Y L,Gao Q K,Zhang S G,Li H F 2013Opt.Lett.38 1425
[6]Yang N,Gao Q K,Shi Y S 2018 Opt.Express 26 31995
[7]Su Y,Tang C,Li B,Chen X,Xu W,Cai Y 2017 Appl.Opt.56 498
[8]Liu Z,Dai J,Sun X,Liu S 2010 Opt.Lasers Eng.48 800
[9]Abuturab M R 2012 Appl.Opt.51 3006
[10]Sui L S,Xin M T,Tian A L,Jin H 2013 Opt.Lasers Eng.511297
[11]Xiao D,Xie Y J 2013 Acta Phys.Sin.62 240508(in Chinese)[肖迪,谢沂均2013物理学报62 240508]
[12]Qin Y,Zheng C B 2012 Acta Phot.Sin.41 326(in Chinese)[秦怡,郑长波2012光子学报41 326]
[13]Yuan Q P,Yang X P,Gao L J,Zhai H C 2009 Optoelectron.Lett.5 147
[14]Faraoun K M 2014 Opt.Laser Technol.64 145
[15]Liu Z,Guo C,Tan J,Liu W,Wu J,Wu Q,Pan L,Liu S2015 Opt.Lasers Eng.68 87
[16]Gao L J,Yang X P,Li Z L,Wang X L,Zhai H C,Wang MW 2009 Acta Phys.Sin.58 1053(in Chinese)[高丽娟,杨晓苹,李智磊,王晓雷,翟宏琛,王明伟2009物理学报58 1053]
[17]Yang X P,Gao L J,Wang X L,Zhai H C,Wang M W 2009Acta Phys.Sin.58 1662(in Chinese)[高丽娟,杨晓苹,李智磊,王晓雷,翟宏琛,王明伟2009物理学报58 1662]
[18]Zhou N R,Wang Y X,Gong L H,He H,Wu J H 2011 Opt.Commun.284 2789
[19]Wang X,Zhao D 2012 Opt.Express 20 11994
[20]Ding X L,Yuan Q,Zhang L B 2014 Laser Technol.38 561(in Chinese)[丁湘陵,袁倩,张乐冰2014激光技术38 561]
[21]Xi S X,Wang X L,Song L P,Zhu Z Q,Yu N N,Wang H Y2017 Opt.Express 25 8212