A hologram generating apparatus is provided. The apparatus includes a hologram signal generating unit configured to, based on light projected on at least some points corresponding to an object, generate a hologram signal corresponding to the at least some points on at least one two-dimensional plane, a processor configured to calculate a sparsity corresponding to the two-dimensional plane based on the hologram signal, and to calculate a fringe pattern based on at least some of the hologram signal, and a pattern writing unit configured to record the fringe pattern on a computer-generated holography (CGH) plane, wherein the processor is further configured to repeatedly calculate a fringe pattern until a number of dominant signals of the calculated fringe pattern coincides with a predetermined threshold value determined based on the sparsity.