High Capacity Steganography via Optical Phase-Encoding and Transport of Intensity Equation

A high capacity steganography based on optical phase-encoding and transport of intensity equation (TIE) is proposed. The secret image is phase-encoded and then attached a real-valued host image to form a complex light field, which diffracts a short distance and generate a slightly different complex amplitude. Its intensity is recorded and the corresponding amplitude is calculated as the stegoimage. For extraction, the secret image could be reconstructed near perfectly by using the TIE method. It is well known that the capacity and the imperceptibility are two fundamental but contrary attributes in any a steganography scheme. However, in this work, the high capacity could be attained while the imperceptibility is well preserved based on the phase-encoding and TIE method. As the steganography is applied mainly on the digital media which are transmitted through the Internet, the optical experiments are not essential in this situation, and we only provide the simulation results to verify the validity and feasibility of our method.