Layer-based hologram generation using diffraction calculation with minimum zero-padding

Holographic displays are a promising three-dimensional (3D) display technology because holography can reproduce wavefronts from 3D objects. In holographic displays, the calculation of the hologram is significant, and a layer-based approach is com- monly used. The layer-based method generates holograms by employing multiple diffraction calculations with zero-padding to convert circular convolution into linear convolution. Generally, zero-padding extends the calculation region to twice its original size both horizontally and vertically. However, this can be computationally and memory-wasteful. This study proposes a layer- based hologram generation method using diffraction calculation with minimal zero-padding. The strategy of minimal zero-padding is straightforward: The zero-padding region is extended by taking the diffraction angle into account.