The main purpose of this article is to develop a program package which generates artificial holograms by numerical methods and these computer generated holograms are numerically reconstructed. For the calculation of light propagation needed in the generation of holograms or in the reconstruction of the object from the hologram, we use two strategies, the first is the Fourier-based algorithm and the second uses finite difference discretization, and numerical tests that assess the accuracy of these algorithms are presented. © 2007 American Institute of Physics.