Optical Image Encryption Using Devil’s Vortex Toroidal Lens in the Fresnel Transform Domain

Table 1

Image	Original image			Cipher image
	Horizontal	Diagonal	Vertical	Horizontal	Diagonal	Vertical
Lena	0.9562	0.9509	0.9817	0.0093	0.0121	0.0086
OPT	0.9497	0.9354	0.9695	0.0106	0.0020	0.0092