Alternative representation for optimized phase compression in holographic data

Abstract

Recent advances in phase only liquid crystal on silicon spatial light modulators are making the prospect of commercial fully holographic display a distinct possibility in the near future. There are, however, many remaining challenges when dealing with holographic data. In particular, widespread lossless image compression algorithms like the Lempel-Ziv-Welch and DEFLATE show poor performance when applied to the phase of holographic data from diffuse objects. This effect is caused by the discontinuous nature of phase. We propose an alternative phase representation that reduces these discontinuities. This representation is then processed with common lossless compression algorithms, achieving a significant volume reduction when compared with the direct compression of the original phase. We demonstrate the effectiveness of our proposal using experimentally registered holograms of diffuse objects. Up to a fivefold increase in compression ratio is achieved with our technique. Experimental reconstruction of the compressed holograms is also tested.