Data hiding in complex-amplitude modulation using a digital micromirror device

Abstract A digital micromirror device (DMD) is conventionally an amplitude-type binary spatial light modulator. However, the complex-amplitude light modulation with a DMD can be achieved using a superpixel scheme. In the superpixel scheme, we notice that multiple different DMD local block patterns may correspond to the same complex-amplitude superpixel value. Based on this inherent encoding redundancy, a large amount of external data can be embedded into the DMD pattern without extra cost. Meanwhile, the original complex light field information carried by the DMD pattern is fully preserved and almost no quality degradation will be caused by the embedded data. This proposed data hiding or watermarking scheme is favorable for applications such as secure information transmission and copyright protection in holographic display.