Holographic 3D Display Using Depth Maps Generated by 2D-to-3D Rendering Approach

Holographic display has the potential to be utilized in many 3D application scenarios because it provides all the depth cues that human eyes can perceive. However, the shortage of 3D content has limited the application of holographic 3D displays. To enrich 3D content for holographic display, a 2D to 3D rendering approach is presented. In this method, 2D images are firstly classified into three categories, including distant view images, perspective view images and close-up images. For each category, the computer-generated depth map (CGDM) is calculated using a corresponding gradient model. The resulting CGDMs are applied in a layer-based holographic algorithm to obtain computer-generated holograms (CGHs). The correctly reconstructed region of the image changes with the reconstruction distance, providing a natural 3D display effect. The realistic 3D effect makes the proposed approach can be applied in many applications, such as education, navigation, and health sciences in the future.

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Scaling of Three-Dimensional Computer-Generated Holograms with Layer-Based Shifted Fresnel Diffraction

Applied Sciences ◽

10.3390/app9102118 ◽

2019 ◽

Vol 9 (10) ◽

pp. 2118 ◽

Cited By ~ 2

Author(s):

Hao Zhang ◽

Liangcai Cao ◽

Guofan Jin

Keyword(s):

Three Dimensional ◽

Fresnel Diffraction ◽

Depth Image ◽

Depth Information ◽

Display System ◽

3D Images ◽

Holographic Display ◽

Computer Generated Holograms ◽

3D Scene ◽

Human Eyes

Holographic three-dimensional (3D) displays can reconstruct a whole wavefront of a 3D scene and provide rich depth information for the human eyes. Computer-generated holographic techniques offer an efficient way for reconstructing holograms without complicated interference recording systems. In this work, we present a technique for generating 3D computer-generated holograms (CGHs) with scalable samplings, by using layer-based diffraction calculations. The 3D scene is partitioned into multiple layers according to its depth image. Shifted Fresnel diffraction is used for calculating the wave diffractions from the partitioned layers to the CGH plane with adjustable sampling rates, while maintaining the depth information. The algorithm provides an effective method for scaling 3D CGHs without an optical zoom module in the holographic display system. Experiments have been performed, demonstrating that the proposed method can reconstruct quality 3D images at different scale factors.

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Computer-Generated Hologram Based on Reference Light Multiplexing for Holographic Display

Applied Sciences ◽

10.3390/app11167199 ◽

2021 ◽

Vol 11 (16) ◽

pp. 7199

Author(s):

Dapu Pi ◽

Juan Liu

Keyword(s):

Image Quality ◽

Numerical Simulations ◽

Light Wave ◽

Information Capacity ◽

Improve Image Quality ◽

Multiple Images ◽

Holographic Display ◽

Light Waves ◽

Computer Generated Holograms ◽

Holographic Displays

In this article, we propose a reference light wave multiplexing scheme to increase the information capacity of computer-generated holograms. The holograms were generated by different reference light waves and superimposed together as a multiplexed hologram. A modified Gerchberg–Saxton algorithm was used to improve image quality, and different images could be reconstructed when the multiplexed hologram was illuminated by corresponding reference light waves. We performed both numerical simulations and optical experiments to demonstrate the feasibility of the proposed scheme. Numerical simulations showed that the proposed method could reconstruct multiple images successfully by a single multiplexed hologram and optical experiments are consistently good with numerical simulations. It is expected that the proposed method has great potential to be widely applied in holographic displays in the future.

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The Zerotrope, a Dynamic Holographic Display: Design and Implementation

Applied Sciences ◽

10.3390/app9163378 ◽

2019 ◽

Vol 9 (16) ◽

pp. 3378

Author(s):

Philippe Gentet ◽

Jinbeom Joung ◽

Yves Gentet ◽

Kwang-Jib Kim ◽

Seung-Hyun Lee

Keyword(s):

Constant Speed ◽

3D Display ◽

Display Design ◽

Holographic Display ◽

Design And Implementation ◽

Full Color ◽

Zero Degree ◽

Stop Motion

This paper presents the Zerotrope, an improved version of the classic phenakistiscope and zoetrope devices. This device is used to create a new 360-degree dynamic 3D display by the inclusion of a single ultra-realistic full-color hologram. The Zerotrope is built with a zero-degree transplane hologram mounted on a disk rotating at a constant speed. When a stroboscopic lamp synchronized with the rotation illuminates this hologram, the recorded characters, arranged radially around the center of the disk, are animated as in a stop-motion movie. The operation of the Zerotrope is successful and shows the effect of a 3D display without the need for special viewing aids.

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