Generation of distortion-free scaled holograms using light field data conversion

Abstract

A novel method to convert holograms for their scaled three-dimensional image reconstructions is proposed. Conventional methods that directly scale the hologram itself or simulate the optical imaging have a limitation that axial magnification of the reconstruction is different from the transverse magnification, causing distortion. In order to achieve constant transverse and axial magnifications, the proposed method performs the scaling in the light field data domain. The proposed method first extracts the light field from a hologram and performs the scaling to the light field data. The modified light field is then used to synthesize a new hologram. For the transformation between the hologram domain and the light field domain, angular spectrum bandpass filtering and non-hogel based computer generated hologram techniques are utilized. The linear nature of the light field data ensures the distortion free scaling with the same transverse and axial magnification of the reconstruction. The proposed method is verified by optical experiments.