Opto-digital image encryption by using Baker mapping and 1-D fractional Fourier transform

We present an optical encryption method based on the Baker mapping in one-dimensional fractional Fourier transform (1D FrFT) domains. A thin cylinder lens is controlled by computer for implementing 1D FrFT at horizontal direction or vertical direction. The Baker mapping is introduced to scramble the amplitude distribution of complex function. The amplitude and phase of the output of encryption system are regarded as encrypted image and key. Numerical simulation has been performed for testing the validity of this encryption scheme.

► Amplitude information is scrambled by Baker mapping.
► The changeable 1D fractional Fourier transform is used for hiding image.
► An electro-optical system is designed and applied in the encryption method.