• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.571-572
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• 2020

3D 디스플레이 산업에 있어서 홀로그램의 상용화는 여전히 많은 문제점을 가지고 있다. Computer Generated Hologram(CGH)은 홀로그램 분야 중에서도 3D 물체를 생성하는데 여러 가지 강점을 가지고 있지만 큰 해상도를 가진 CGH를 생성하는데 많은 연산시간이 걸려 상업화에 걸림돌이 되고 있다. 이 논문에서는 이를 해결하기 위하여 오목 렌즈 함수를 이용한 초 고해상도 CGH를 생성하는 알고리즘을 이용하여 초 고해상도 홀로그램을 생성하는 방법을 제안하였다. 초 고해상도 CGH를 생성하기 위하여 필요한 일반적인 방법으로 실제로 계산해야 될 CGH의 크기는 4 메가픽셀(2k X 2k) 수준의 저해상도로서, 저사양의 컴퓨터로서도 충분히 빠르고 부담 없이 계산해낼 수 있는 사이즈이다. 생성된 CGH로 Array를 형성한 후, 해당 위치에 알맞은 임의의 오목 렌즈 함수를 곱해줌으로서 임의의 크기 및 복원 거리를 가지는 초고해상도 CGH를 생성할 수 있음을 확인하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.246-249
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• 2022

최근 들어 세계적으로 크게 관심을 받는 메타버스 및 몰입형(가상현실, 확장현실, 및 라이트필드) 콘텐츠 서비스의 응용 범위를 확대하기 위해서는 3D 객체의 실시간 전송을 위한 압축 기술이 필요하다. ISO/IEC 23090 MPEG-I Part 5 로 2021 년 표준화 완료된 V-PCC (Video-based Point Cloud Compression)는 이러한 산업계의 관심 및 필요에 의해서 국제 표준화된 동적 3D 포인트 클라우드 객체 부호화 기술이다. V-PCC 기술의 압축 성능은 기존 산업계 기술에 비해 매우 우수하나, 부호화기의 연산 복잡도가 매우 높다는 단점을 가지고 있다. 본 논문에서는 V-PCC 부호화기에서 가장 높은 연산 복잡도를 갖는 법선 추정 알고리즘의 결합 고속화 기법을 제안한다. 법선 추정은 2 개의 알고리즘으로 구성되어 있다. 첫번째는 "방향을 무시하는 법선 추정 알고리즘(normal estimation)"이고, 두번째는 첫번째 알고리즘에서 추정된 법선들을 대상으로 하는 "법선 방향 추정 알고리즘(normal orientation)"이다. 본 논문에서 제안하는 고속화 기법은 2 개 알고리즘을 결합하여 첫번째 법선 추정 알고리즘에서 획득한 부가 정보를 두번째 법선 방향 추정 알고리즘에서 활용함으로써 연산량을 대폭 줄이고, 또한 법선 방향 추정 알고리즘 내의 우선순위 큐 자료구조를 변경하여 추가적인 고속화를 달성한다. 7 개 테스트 영상에 대한 실험 결과, 압축 효율 저하 없이 법선 방향 추정 알고리즘의 속도를 평균 89.2% 향상시킬 수 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.635-638
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• 2009

The latest, Digital art is attempt new field's Art, that is utilize variously digital media image, sound, simulation, 3D holography. A large number of Digital Art is contact with the audiance in pavilion(limit place and limit period). However, It will be possible, If Digital Art can use place digital form media even there are indoor, outdoor, anywhere. This paper analyze reciprocal action for utilize Digital Art in indoor space design, and this paper study expression about indoor design base of interactive.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.276-284
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• 2022

In this paper, we implemented cloud rendering using WebRTC for high-quality AR and VR services. Cloud rendering is an applied technology of cloud computing. It efficiently handles the rendering of large volumes of 3D content. The conventional VR and AR service is a method of downloading 3D content. The download time is delayed as the 3D content capacity increases. Cloud rendering is a streaming method according to the user's point of view. Therefore, stable service is possible regardless of the 3D content capacity. In this paper, we implemented cloud rendering using WebRTC and analyzed its performance. We compared latency of 100MB, 300MB, and 500MB 3D AR content in 100Mbps and 300Mbps internet environments. As a result of the analysis, cloud rendering showed stable latency regardless of data volume. On the other hand, the conventional method showed an increase in latency as the data volume increased. The results of this paper quantitatively evaluate the stability of cloud rendering. This is expected to contribute to high-quality VR and AR services

• Journal of Broadcast Engineering
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• v.17 no.3
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• pp.491-502
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• 2012

Flat panel-based parallax barrier or lenticular based 3D display devices that have been developed recently are designed to feel depth. In order to see a three-dimensional(3D) image by the display device, a multi-view image displayed on the flat panel must be regenerated from images of multi-views using a subsampling method. Previous subsampling methods are focused on reducing crosstalk. In this paper, we focus on a misalignment that is occurred on manufacture process of slanted parallax barrier based autostereoscopic display device. Therefore, we propose a interleaving method that considers tilt of slanted parallax barrier, aperture size, and distance between an autostereoscopic display device and a viewer to see a 3D image regardless of a viewer position.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.126-139
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• 2023

At present, naked-eye 3D appears more and more commonly on the facades of urban buildings. It brings an incredible visual experience to the audience by simulating the natural 3D 3D space effect. At the same time, it also creates enormous commercial value for city publicity and commercial advertisements. There is much research on naked-eye 3D visual effects, but for right-angle LED screens. Right-angle LED screen's brand-new expression method that has only become popular in recent years, how to convey a realistic naked-eye 3D effect through two LED screens combined at right angles has become a problem worth exploring. To explore the whole design ideas and production process of the naked-eye 3D impact of the right-angle LED screen, this paper is a preliminary study aimed at understanding the performance principle and expression features. Before the case analysis, first, understand the standard virtual 3D space construction techniques. Combining it with the optical illusion phenomenon, according to the expression principle of the naked-eye 3D effect of the right-angle LED screen, it can be summarized into seven expressions: Shadow, Color contrast, Background structure line, Magnify object, Object out of bounds, Object floating, Fusion of picture and background. By analyzing the optical illusion phenomenon used in the case, we summarized the main performance characteristics of the naked eye 3D effect. The emergence of right-angle LED screens breaks the limitation of a single plane of optical illusion art, perfectly combines building facades with naked-eye 3D visual effects, and provides designers with a brand-new creative platform. Understanding its production principles and main expressive features can help designers enter this innovative platform better.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.4
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• pp.181-185
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• 2017

In this paper, for Broadband Wireles LAN dual-band antenna was designed to satisfy the bandwidth of 2.32GHz and 5.79GHz. the substrate of proposed microstrip antenna is FR-4(er=4.3) and $34mm{\times}50mm{\times}1.5mm$ size and thickness t=0.035mm, and the simulation was used for CST Microwave Studio 2014. input return loss compared -10dB less than operates at and when gain 2.32GHz -19.321dB, 5.79GHz showed the results of -13.033dB. It increased impedance matching, minimized interference between adjacent frequencies, simplified small manufacturing methods, and demonstrated the characteristics of non-directional properties. Thus the proposed antenna satisfied the -10 dB impedancebandwidth requirement while simultaneously covering the Broadband Wireless LAN.

• Journal of Broadcast Engineering
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• v.10 no.3
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• pp.321-327
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• 2005

A MVC (Multi-view Video Coding) method, which uses both an illumination change-adaptive ME (Motion Estimation)/DC (Motion Compensation) and a 2D (Dimensional) direct mode, is proposed. Firstly, a new SAD (Sum of Absolute Difference) measure for ME/MC is proposed to compensate the Luma pixel value changes for spatio-temporal motion vector prediction. Illumination change-adaptive (ICA) ME/MC uses the new SAD to improve both MV (Motion Vector) accuracy and bit saving. Secondly, The proposed 2D direct mode that can be used in inter-view prediction is an extended version of the temporal direct mode in MPEG-4 AVC. The proposed MVC method obtains approximately 0.8dB PSNR (Peak Signal-to-Noise Ratio) increment compared with the MPEG-4 AVC simulcast coding.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.1
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• pp.35-43
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• 2022

In this paper, a study was conducted to produce 20W by combining a 10W MMIC and raising the unit power amplifier to 100W SSPA by combining the 8-way spatial coupler. SSPA requires low-loss, high-efficiency coupling techniques to meet high output with the output of a single element relatively low compared to TWTA. Designed and produced in this paper, the SSPA was manufactured as a 100W SSPA by mounting eight 20W high-power amplification modules in an 8-way spatial coupler with a reflection loss of 20dB or more and an excellent coupling efficiency of 94% or more. When -10dBm was applied, it was 112.2~169.8W at 20kHz 20%, 125.9~173.8W at 400kHz 40%, 117.5~162.2W at 800kHz 40%, showing performance of over 60dB and over 100W in all three PRF conditions.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.140-147
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• 2024

In Current artificial structures, we must periodically make their safety inspections. In this process, we should consider the safety of workers and the accuracy of safety checks and also consider time and cost savings for safety inspections. Additionally, in the fields of architecture and civil engineering, we are unavoidable the use of foreign commercialized BIM model tools. To address these challenges, we propose mapping crack areas and BIM 3D design drawings based on augmented reality (AR) for the safety inspection of Huge Bridges. For this purpose, we define indexing of 2D/3D drawing models, create the tabulation of all 2D/3D drawings into a database, analyze QR codes, and finally integrate with augmented reality devices. we may expect our method to improve the efficiency of safety inspections on bridge sites. Moreover, we will enable the domestics of our pure technology.