Real-time gradation-expressible amplitude-modulationtype electroholography based on binary-weighted computer-generated hologram

In amplitude-modulation-type electroholography, the binary-weighted computer-generated hologram(BW-CGH) facilitates the gradation-expressible reconstruction of three-dimensional(3 D) objects. To realize real-time gradation-expressible electroholography, we propose an efficient and high-speed method for calculating bit planes consisting of BW-CGHs. The proposed method is implemented on a multiple graphics processing unit(GPU) cluster system comprising 13 GPUs. The proposed BW-CGH method realizes eight-gradation-expressible electroholography at approximately the same calculation speed as that of conventional electroholography based on binary computer-generated holograms. Consequently, we were able to successfully reconstruct a real-time electroholographic 3 D video comprising approximately 180,000 points expressed in eight gradations at 30 frames per second.

High-speed playback of spatiotemporal division multiplexing holographic 3D video stored in a solid-state drive using a digital micromirror device

We propose a high-speed playback method for the spatiotemporal division multiplexing electroholographic three-dimensional(3D)video stored in a solid-state drive(SSD)using a digital micromirror device.The spatiotemporal division multiplexing electroholography prevents deterioration in the reconstructed 3D video from a 3D object comprising many object points.In the proposed method,the stored data is remarkably reduced using the packing technique,and the computer-generated holograms are played back at high speed.Consequently,we successfully reconstructed a clear 3D video of a 3D object comprising approximately 1,100,000 points at 60 frames per second by reducing the reading time of the stored data from an SSD.