Abstract

A compression method for phase-shifting digital holographic data is presented. We used Fresnelets in phase shifting digital holography (PSDH) for the compression of such holographic data. Four interference patterns and one file containing intensity of the object are recorded. The complex wavefront in the camera plane is extracted by applying the phase shifting algorithm. This phase and amplitude information of the digital hologram is then propagated to the object plane using the Fresnel transformation. Standard JPEG-2000 image compression techniques are applied to the Fresnel-reconstructed interference patterns to reduce the amount of data to be stored. Currently JPEG-2000 implements a rate distortion optimized rate allocation, meaning it selects data included in the bit stream in such a way that the distortion is minimal for a given target rate. In our experiment JPEG-2000 compression is applied to Fresnel-transformed wavefronts at different target rates and the results are verified with real holographic data. The results show that the Fresnel transform of phase-shifting holograms in combination with EBCOT encoder of JPEG-2000 can be used very effectively for the compression of holographic data.