A method for synthesizing a 360° computer-generated spherical hologram of real-existing objects is proposed. The whole three-dimensional (3-D) information of a real object is extracted by using a depth camera to capture multiple sides of the object. The point cloud sets which are obtained from corresponding sides of the object surface are brought into a common coordinate system by point cloud registration process. The modeled 3-D point cloud is then processed by hidden point removal method in order to identify visible point set for each spherical hologram point. The hologram on the spherical surface is finally synthesized by accumulating spherical waves from visible object points. By reconstructing partial region of the calculated spherical hologram, the corresponding view of the 3-D real object is obtained. The principle is verified via optical capturing using a depth camera and numerical reconstructions.

Light field displays comprise three-dimensional (3D) visual information presentation devices capable of providing realistic and full parallax autostereoscopic images. In this letter, the recent advances in the light field displays based on integral imaging (II) and holographic techniques are presented. Several advanced approaches to demonstrate the light field displays including viewing angle enhancement techniques of the II display, a fast hologram generation method using graphics processing unit (GPU) and multiple WRPs, and a holographic microscopy to display the living cells are reported. These methods improve some important constraints of the light field displays and add new features.

In this paper we present the method for fast computer generation hologram (CGH) of the long depth object using multiple wavefront recording planes (WRP). The wavefront recording planes are placed between object plane and hologram plane. Each WRP records the wavefront from a section of object. For a long depth object, multiple WRPs can reduce the calculation time and also enhance the quality of reconstruction object in comparison with those ones of single WRP. The hologram of object can be real time generated by out proposed method.

A method for fast computer hologram generation for long-depth objects using double wavefront recording planes (WRPs) and a graphics-processing unit (GPU) is presented. The WRPs are placed between the object and the hologram plane. Each WRP records the wavefront from a section of the object. Double WRPs can provide a shorter calculation time and enhanced reconstructed image quality compared with a single WRP, especially for long-depth objects. The average generation speed of two WRPs is 2.5 times that of one WRP. The correlation efficiency of the reconstructed layer relative to the original is 94% for two WRPs and 88.3% for one WRP at the close depth layer.

In this paper, we use multipoint light source illumination to enhance the resolution of digital holographic microscopy. The specimen is sequentially illuminated from many directions by using multipoint light sources which are created by a lens-array. The high spatial frequency information of the specimen is directed to the limited numerical aperture of the objective lens and captured at a fixed position of image sensor. The threedimensional information of the specimen can be reconstructed with enhanced resolution by reconstructing the captured holograms.