Image hiding scheme by use of rotating squared sub-image in the gyrator transform domains

An image hiding scheme is proposed based on the scrambling process composed of the rotation of the squared sub-image in the gyrator transform domains. A squared sub-image is first selected from a secret image and is rotated along an axis, which is the center line or diagonal line of the sub-image. The rotation operation will be performed iteratively for utilizing more parameters being regarded as key. Subsequently, the rotated image is converted by gyrator transform into a complex function. The amplitude distribution and phase distribution are scrambled by the rotation process with different parameters. Finally, the encrypted image is obtained by gyrator transform from the rotated complex function. Numerical simulation is given to test the validity of the image encryption algorithm.

► A kind of random rotating operation and overturning operation is defined for encrypting an image.
► The rotation operation is employed iteratively for scrambling secret data.
► The proposed image encryption scheme can be implemented with an electro-optical system.