Compression of encrypted three-dimensional objects using digital holography

Abstract

We present the results of applying data compression techniques to encrypted three-dimensional objects. The objects are captured using phase-shift digital holography and encrypted using a random phase mask in the Fresnel domain. Lossy quantization is combined with lossless coding techniques to quantify compression rates. Lossless compression alone applied to the encrypted holographic data achieves compression rates lower than 1.05. When combined with quantization and an integer encoding scheme, this rises to between 12 and 65 (depending on the hologram chosen and the method of measuring compression rate) with good decryption and reconstruction quality. Our techniques are suitable for a range of secure three-dimensional object storage and transmission applications.

Keywords: digital holography, image compression, optical encryption, three-dimensional image processing.

Copyright 2004 Society of Photo-Optical Instrumentation Engineers.
This paper was published in the Journal of Optical Engineering volume 43 and is made available as an electronic reprint with permission of SPIE. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.