Effective generation of digital holograms of three-dimensional objects using a novel look-up table method
TL;DR: A novel approach to dramatically reduce the size of the conventional LUT, still keeping its advantage of fast computational speed, is proposed, which is called here a novel LUT (N-LUT) method.
Abstract: Several approaches for increasing the speed in computation of the digital holograms of three-dimensional objects have been presented with applications to real-time display of holographic images. Among them, a look-up table (LUT) approach, in which the precalculated principal fringe patterns for all possible image points of the object are provided, has gained a large speed increase in generation of computer-generated holograms. But the greatest drawback of this method is the enormous memory size of the LUT. A novel approach to dramatically reduce the size of the conventional LUT, still keeping its advantage of fast computational speed, is proposed, which is called here a novel LUT (N-LUT) method. A three-dimensional object can be treated as a set of image planes discretely sliced in the z direction, in which each image plane having a fixed depth is approximated as some collection of self-luminous object points of light. In the proposed method, only the fringe patterns of the center points on each image plane are precalculated, called principal fringe patterns (PFPs) and stored in the LUT. Then, the fringe patterns for other object points on each image plane can be obtained by simply shifting this precalculated PFP according to the displaced values from the center to those points and adding them together. Some experimental results reveal that the computational speed and the required memory size of the proposed approach are found to be 69.5 times faster than that of the ray-tracing method and 744 times smaller than that of the conventional LUT method, respectively.
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20 Nov 2020
TL;DR: Compared with other 3D displays, the holographic display has unique advantages in providing natural depth cues and correcting eye aberrations and holds great promise to be the enabling technology for next-generation VR/AR devices.
Abstract: Wearable near-eye displays for virtual and augmented reality (VR/AR) have seen enormous growth in recent years. While researchers are exploiting a plethora of techniques to create life-like three-dimensional (3D) objects, there is a lack of awareness of the role of human perception in guiding the hardware development. An ultimate VR/AR headset must integrate the display, sensors, and processors in a compact enclosure that people can comfortably wear for a long time while allowing a superior immersion experience and user-friendly human–computer interaction. Compared with other 3D displays, the holographic display has unique advantages in providing natural depth cues and correcting eye aberrations. Therefore, it holds great promise to be the enabling technology for next-generation VR/AR devices. In this review, we survey the recent progress in holographic near-eye displays from the human-centric perspective.
175 citations
TL;DR: A rapid calculation method of Fresnel computer-generated-hologram (CGH) using look-up table and wavefront-recording plane (WRP) methods toward three-dimensional (3D) display is presented.
Abstract: A rapid calculation method of Fresnel computer-generated-hologram (CGH) using look-up table and wavefront-recording plane (WRP) methods toward three-dimensional (3D) display is presented. The method consists of two steps: the first step is the calculation of a WRP that is placed between a 3D object and a CGH. In the second step, we obtain an amplitude-type or phase-type CGH to execute diffraction calculation from the WRP to the CGH. The first step of the previous WRP method was difficult to calculate in real-time due to the calculation cost. In this paper, in order to obtain greater acceleration, we apply a look-up table method to the first step. In addition, we use a graphics processing unit in the second step. The total computational complexity is dramatically reduced in comparison with conventional CGH calculations. We show optical reconstructions from a 2,048×2,048 phase-type CGH generated by about 3×10(4) object points over 10 frames per second.
158 citations
TL;DR: Three different techniques, an improved coding scheme, a multilayer depth- fused 3D method and a fraction method are introduced to improve the calculation speed and depth cues quality of layer-based method for holographic image display.
Abstract: Layer-based method has been proposed as an efficient approach to calculate holograms for holographic image display. This paper further improves its calculation speed and depth cues quality by introducing three different techniques, an improved coding scheme, a multilayer depth- fused 3D method and a fraction method. As a result the total computation time is reduced more than 4 times, and holographic images with accommodation cue are calculated in real time to interactions with the displayed image in a proof-of-concept setting of head-mounted holographic displays.
151 citations
TL;DR: The recent progress in the CGH techniques is reviewed, covering the point-cloud-, light-ray-field-, layer-, and polygon-based techniques.
Abstract: Computer-generated holography (CGH) is a crucial technique in preparing contents for holographic three-dimensional displays. In this paper, the recent progress in the CGH techniques is reviewed, covering the point-cloud-, light-ray-field-, layer-, and polygon-based techniques.
130 citations
TL;DR: In this approach, object points to be involved in calculation of the CGH pattern can be dramatically reduced and, as a result, an increase of computational speed can be obtained.
Abstract: In this paper we propose a new approach for fast generation of computer-generated holograms (CGHs) of a 3D object by using the run-length encoding (RLE) and the novel look-up table (N-LUT) methods. With the RLE method, spatially redundant data of a 3D object are extracted and regrouped into the N-point redundancy map according to the number of the adjacent object points having the same 3D value. Based on this redundancy map, N-point principle fringe patterns (PFPs) are newly calculated by using the 1-point PFP of the N-LUT, and the CGH pattern for the 3D object is generated with these N-point PFPs. In this approach, object points to be involved in calculation of the CGH pattern can be dramatically reduced and, as a result, an increase of computational speed can be obtained. Some experiments with a test 3D object are carried out and the results are compared to those of the conventional methods.
119 citations
References
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IBM1
TL;DR: A theory for binary holograms is developed that is equivalent in terms of image reconstruction with ordinary holograms, proven theoretically and verified experimentally.
Abstract: When a hologram is desired from an object which does not exist physically but is known in mathematical terms, one can compute the hologram. An automatic plotter will make a drawing at a large scale which is then reduced photographically. Since the drawing can contain only black and white areas, we have developed a theory for binary holograms. They are equivalent in terms of image reconstruction with ordinary holograms. This has been proven theoretically and verified experimentally.
834 citations
TL;DR: Several methods of increasing the speed and simplicity of the computation of off-axis transmission holograms are presented, with applications to the real-time display ofholographic images.
Abstract: Several methods of increasing the speed and simplicity
of the computation of off-axis transmission holograms are presented, with applications to the real-time display ofholographic images. The bipolar intensity approach allows for the real-valued linear summation
of interference fringes, a factor of 2 speed increase, and the elimination of image noise caused by object self-interference. An order of magnitude speed increase is obtained through the use of a precomputed look-up table containing a large array of elemental interference patterns corresponding to point source contributions from each of the possible locations in image space. Results achieved using a data-parallelsupercomputer to compute horizontal-parallaxonly holographic patterns containing six megasamples indicate that an image comprised of 10,000 points with arbitrary brightness (gray
scale) can be computed in under 1 s. Implemented on a common workstation, the look-up table approach increases computation speed by a factor of 43.
508 citations
TL;DR: This work proposes a method of synthesizing computer-generated holograms of real-life three-dimensional (3-D) objects by using an ordinary digital camera to record several projections of the 3-D object from different points of view.
Abstract: We propose a method of synthesizing computer-generated holograms of real-life three-dimensional (3-D) objects. An ordinary digital camera illuminated by incoherent white light records several projections of the 3-D object from different points of view. The recorded data are numerically processed to yield a two-dimensional complex function, which is then encoded as a computer-generated hologram. When this hologram is illuminated by a plane wave, a 3-D real image of the object is reconstructed.
82 citations
TL;DR: The first article of a four-part series as discussed by the authors explores how optics can be used to create 3D illusions, and the tour is continued in the next part of the series.
Abstract: First article of a four-part series. You are invited to explore the wonderful world of three-dimensional imaging. The tour begins with this article, which explains how optics can be used to create 3D illusions.
60 citations
18 Jun 2007
TL;DR: The Reduced Look-up Table is proposed to increase the speed of CGH generation and to reduce the space required to store a precomputed table.
Abstract: In this paper, the Reduced Look-up Table is proposed to increase the speed of CGH generation and to reduce the space required to store a precomputed table.
2 citations