Pre-calculated object light-based fast calculation method for computer-generated hologram

Computer generated holograms are expected to be an ideal three-dimensional display system. Enormous computation time, however, is required to calculate holograms. There are fast calculation methods based on fast Fourier transforms using a patch model, but they require two-dimensional fast Fourier transforms for each patch. Therefore, calculating the object light from a complex object that has many patches takes much computation time. We propose a fast calculation method using pre-calculated object light without the fast Fourier transform and show the results of our method. Our method calculates object lights from complex objects including large-angle tilted patches using only one cylindrical pre-calculated object light. The memory needed for pre-calculated object light is smaller than the previously proposed method.