Image Information Hiding Based on CGH of Phase-Only Interference Holography

An image information hiding technique based on computer-generated hologram (CGH) of phase-only interference holography is proposed to significantly improve the traditional method. The importance of the phase in transformation is analyzed. Compared with the traditional method, the phase-only wave instead of complex function of the traditional Fourier-transformed object wave, which then is used to interfere with the reference wave and a high contrast CGH is obtained. The hologram is encrypted by security key and is superposed on discrete-cosine-transform domain of the host image. In the detection stage, the original information is extracted based on optical or digital inverse Fourier transform with the security key. Theoretical analysis and simulation results show that the improved method received better robustness than traditional information hiding technology based on CGH.