• Journal of the Optical Society of Korea
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• v.5 no.2
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• pp.43-48
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• 2001

A three-dimensional (3D) display system based on computer-generated integral photography (CGIP) is proposed and its feasibility is discussed. Instead of the pickup process in conventional If, the elemental images of imaginary objects are computer-generated. Using these images, we observed autostereoscopic 3D images in full color and full parallax. The lateral and depth resolutions of the integrated images are limited by some factors such as the image position, object thickness, the lens width, and the pixel size of display panel.

• Journal of the Optical Society of Korea
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• v.5 no.3
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• pp.117-122
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• 2001

A three-dimensional (3D) display system based on computer-generated integral photography (CGIP) is proposed and its feasibility is discussed. Instead of the pickup process in conventional IP, the elemental images of imaginary objects are computer-generated. Using these images, we observed autostereoscopic 3D images in full color and full parallax. The lateral and depth resolutions of the integrated images are limited by some factors such as the image position, object thickness, the lens width, and the pixel size of display panel.

• Information and Communications Magazine
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• v.34 no.2
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• pp.49-58
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• 2017

본고에서는 Computer generated holography (CGH) 기술에 대하여 알아본다. CGH는 3차원 물체에 대한 복소 광파를 계산하는 기술로서 홀로그래픽 디스플레이의 콘텐츠를 생성하는 핵심 기술 중 하나이다. 본 고에서는 대표적인 CGH 기술들인 점광원 기반 CGH, 삼각형 메쉬 기반 CGH, 광선 분포 기반 CGH, 다중 면 기반 CGH 기법들의 원리를 살펴보고, CGH의 최근 기술 동향을 알아본다.

• Journal of the Optical Society of Korea
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• v.12 no.4
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• pp.275-280
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• 2008

We propose a method generating elemental images for the integral imaging using 4-step phaseshifting digital holography. Phase shifting digital holography is a way recording the digital hologram by changing the phase of the reference beam and extracting the complex field of the object beam. Since all 3D information is captured by phase-shifting digital holography, the elemental images for any specifications of the lens array can be generated from single phase-shifting digital holography. In experiment, phase-shifting is achieved by rotating half- and quarter- wave plates and the resultant interference patterns are captured by a $3272{\times}2469$ pixel CCD camera with $27{\mu}m{\times}27{\mu}m$ pixel size.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1753-1756
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• 2007

In the field of 3D display, holographic displays are the only technology allowing optimal user comfort. We have developed systems based on compact projection optics, that allow advantageous new features, like large size full-color3D scenes generated at high rate on a micro-display with state of the art resolution.

• Journal of Broadcast Engineering
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• v.28 no.1
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• pp.21-30
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• 2023

Computer-generated holography requires much more computation costs and memory space rather than image processing. We implemented the diffraction calculation with low-precision and mixed-precision floating point numbers and compared the processing time and quality of the hologram with various precision. We compared diffraction quality with double, single and bfloat16 precision. bfloat16 shows 5.94x and 1.52x times faster performance than double precision and single precision. Also, bfloat16 shows lower PSNR and SSIM and higher MSE than other precision. However, there is no significant effect on reconstructed images. These results show low precision, like bfloat16, can be utilized for computer-generated holography.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.2
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• pp.29-32
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• 2012

Computer generated holography (CGH) is technology for generating holograms of synthetic, three dimensional (3D) objects which may not exist in the physical world. The process, however, requires heavy amount of computation as the resolution of a hologram is significantly higher than that of a typical optical image. This paper reviews four modern techniques for fast generation of digital Fresnel holograms which are important in the development of holographic video systems. The methods that will be described include the virtual window, sub-line, wavefront recording plane (WRP), and the interpolative WRP schemes. These works share the common objective to generate digital Fresnel hologram at a speed that is close to the video frame rate, and with complexity which is realizable with affordable computing and reconfigurable hardware devices. The author will present the principles and realization of these works, as well as some potential area of research in digital holography.

• Journal of Korea Multimedia Society
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• v.19 no.6
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• pp.1043-1051
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• 2016

In this paper, double encryption technique of binary image using random phase mask and 2-step phase-shifting digital holography is proposed. After phase modulating of binary image, firstly, random phase mask to be used as key image is generated through the XOR operation with the binary phase image. And the first encrypted image is encrypted again through the fresnel transform and 2-step phase-shifting digital holography. In the decryption, simple arithmetic operation and inverse Fresnel transform are used to get the first decryption image, and second decryption image is generated through XOR operation between first decryption image and key image. Finally, the original binary image is recovered through phase modulation.

• Electronics and Telecommunications Trends
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• v.32 no.5
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• pp.49-64
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• 2017

Digital holography is a computational operation and photo-electronic technology that enables calculating, encoding, and reconstructing a 3D scene based on the interference of a coherent light-wave field. The spatial light modulator in a holographic 3D display decodes a computer-generated hologram to optically regenerate a 3D scene in various depths, thus facilitating to match convergence and accommodation of the human eyes. This paper introduces recent technologies related with the content for digital holography called an ultimate 3D display.

• Journal of the Korean Physical Society
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• v.73 no.12
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• pp.1845-1848
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• 2018

We introduce a process for optically reconstructing full-color holographic images recorded by optical scanning holography. A complex RGB-color hologram was recorded and converted into a binary hologram using a direct binary search (DBS) algorithm. The generated binary hologram was then optically reconstructed using a spatial light modulator. The discrepancies between the reconstructed object sizes and colors due to chromatic aberration were corrected by adjusting the reconstruction parameters in the DBS algorithm. To the best of our knowledge, this represents the first optical reconstruction of a full-color hologram recorded by optical scanning holography.