Digital holography is the analysis and synthesis of wavefronts by means of digital computers. Here "analysis" means the construction of images of objects and the measurement of their physical characteristics by recording and measur- ing the wavefronts scattered by these objects. The "synthesis" is the reconstruc- tion of a wavefront of an object which is specified numerically. Problems involving the analysis and synthesis of wave fronts arise frequently in modem science and engineering. These are the problems encountered in the use of electromagnetic and sound waves to peer into the interior...