• Title/Summary/Keyword: digital shadow

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Specification and Implementation of Projective Texturing Node in X3D

  • Kim, In-Kwon;Jang, Ho-Wook;Yoo, Kwan-Hee;Ha, Jong-Sung
    • International Journal of Contents
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    • v.12 no.2
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    • pp.1-5
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    • 2016
  • Extensible 3D (X3D) is the ISO standard for defining 3D interactive web- and broadcast-based 3D content integrated with multimedia. With the advent of this integration of interactive 3D graphics into the web, users can easily produce 3D scenes within web contents. Even though there are diverse texture nodes in X3D, projective textures are not provided. We enable X3D to provide SingularProjectiveTexture and MultiProjectiveTexture nodes by materializing independent nodes of projector nodes for a singular projector and multi-projector. Our approach takes the creation of an independent projective texture node instead of Kamburelis's method, which requires inconvenient and duplicated specifications of two nodes, ImageTexture and Texture Coordinate.

A Study on Super Resolution Optimum Beam Steering Pattern for Improvement Moving Target Estimation Accuracy (이동 목표물 추정 정확도를 향상시키기 위한 고 분해능 최적 빔 지향 패턴에 관한 연구)

  • Cho, Sung Kuk;Jeon, Byung Kook;Yang, Gill Mo
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.10 no.4
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    • pp.71-78
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    • 2014
  • Method a target estimation in spatial are mobile wireless communication using network cell and GPS. It have much error that mobile wireless communication depend on cell size. GPS method can't find a target in shadow and inner area. In this paper, we estimate a target as direction of arrival method using adaptive array antenna system. Adaptive array antenna system can obtain desired signal to remove other signal This paper studied digital beamforming method in order to estimation a target. Proposed method is modified optimum weight and antenna error correction to estimation an optimal receive signal. Digital beamforming method decided a signal phase and amplitude from received signal on array antenna element. But if it is not to do error correction of received signal, system performance have decreased. Firstly, we proposed modified optimum weight in order to finding desired target. Secondly, we are error correction of antenna incident signals by optimal weight before digital beamforming method. Thirdly, throughly simulation, we showed that system performance of proposed method compare proposal method with general method. It have improved resolution of estimation target to good performance more proposed method than general method.

Head Position Detection Using Omnidirectional Camera (전 방향 카메라 영상에서 사람의 얼굴 위치검출 방법)

  • Bae, Kwang-Hyuk;Park, Kang-Ryoung;Kim, Jai-Hie
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.283-284
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    • 2007
  • This paper proposes a method of real-time segmentation of moving region and detection of head position in a single omnidrectional camera Segmentation of moving region used background modeling method by a mixture of Gaussian(MOG) and shadow detection method. Circular constraint was proposed for detecting head position.

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CNN-based Shadow Detection Method using Height map in 3D Virtual City Model (3차원 가상도시 모델에서 높이맵을 이용한 CNN 기반의 그림자 탐지방법)

  • Yoon, Hee Jin;Kim, Ju Wan;Jang, In Sung;Lee, Byung-Dai;Kim, Nam-Gi
    • Journal of Internet Computing and Services
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    • v.20 no.6
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    • pp.55-63
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    • 2019
  • Recently, the use of real-world image data has been increasing to express realistic virtual environments in various application fields such as education, manufacturing, and construction. In particular, with increasing interest in digital twins like smart cities, realistic 3D urban models are being built using real-world images, such as aerial images. However, the captured aerial image includes shadows from the sun, and the 3D city model including the shadows has a problem of distorting and expressing information to the user. Many studies have been conducted to remove the shadow, but it is recognized as a challenging problem that is still difficult to solve. In this paper, we construct a virtual environment dataset including the height map of buildings using 3D spatial information provided by VWorld, and We propose a new shadow detection method using height map and deep learning. According to the experimental results, We can observed that the shadow detection error rate is reduced when using the height map.

Application of Simulation for Road Design Evaluation (도로설계 평가를 위한 3차원 시뮬레이션 적용)

  • Kim, Ga-Ya;Jung, Beam-Seok;Kim, Nam-Seok
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.2
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    • pp.121-131
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    • 2008
  • Two dimensional road design is connoting danger factor because different point between design standard and driver's reaction. Consequently two dimensional road design is difficult to recognize problem that happen beforehand when before construction. Therefore three dimensional road design that can grasp problem after completion is required. In this study, three dimensional road was designed to evaluate road that is designed. Road designed by Inroad that is road design program. DTM is created using digital map and elevation data. Three dimensional road was designed by integrated DTM of road and topography. Road design evaluation was performed in three dimension. Driving simulation and sight distance assessment were carried out to estimate stability of alignment. Shadow simulation was executed on icy road section for bad section of icy road surface. As a result of evaluation, this study could confirm shape of road after completion. And sight distance could be calculated and visually confirmed. Also, icy road sections were extracted through shadow simulation.

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Color Correction Using Chromaticity of Highlight Region in Multi-Scaled Retinex

  • Jang, In-Su;Park, Kee-Hyon;Ha, Yeong-Ho
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.59-62
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    • 2009
  • In general, as a dynamic range of digital still camera is narrower than a real scene‘s, it is hard to represent the shadow region of scene. Thus, multi-scaled retinex algorithm is used to improve detail and local contrast of the shadow region in an image by dividing the image by its local average images through Gaussian filtering. However, if the chromatic distribution of the original image is not uniform and dominated by a certain chromaticity, the chromaticity of the local average image depends on the dominant chromaticity of original image, thereby the colors of the resulting image are shifted to a complement color to the dominant chromaticity. In this paper, a modified multi-scaled retinex method to reduce the influence of the dominant chromaticity is proposed. In multi-scaled retinex process, the local average images obtained by Gaussian filtering are divided by the average chromaticity values of the original image in order to reduce the influence of dominant chromaticity. Next, the chromaticity of illuminant is estimated in highlight region and the local average images are corrected by the estimated chromaticity of illuminant. In experiment, results show that the proposed method improved the local contrast and detail without color distortion.

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A Scheme of User Face Recognition using a Moire Phenomenon in IoT Environment (IoT환경에서 무아레 현상을 이용한 사용자 얼굴 인증 기법)

  • Cho, Ik-Hyun;Lee, Keun-Ho
    • Journal of Digital Convergence
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    • v.17 no.2
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    • pp.171-176
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    • 2019
  • In modern times, many IoT products are being used as all things and devices are connected to the Internet and IoT products become easily accessible through the network. For the convenience of users, IoT products can be remotely operated automatically without manual operation. Various research and development are underway to improve the convenience of users by using IoT products. However, since only the convenience of the users is pursued, in terms of security, there is a serious problem that exposes the user's personal information. This paper has proposed a method to apply $moir{\acute{e}}$ technology to IoT products in order to improve the performance of security, and a method to increase the safety of IoT products using user face authentication based on shadow $moir{\acute{e}}$ as a $moir{\acute{e}}$ phenomenon method, and the projection $moir{\acute{e}}$. When comparing the existing IoT products and IoT products applied with $moir{\acute{e}}$ technology, IoT products applied with $moir{\acute{e}}$ technology are safer in terms of security.

Automated Water Surface Extraction in Satellite Images Using a Comprehensive Water Database Collection and Water Index Analysis

  • Anisa Nur Utami;Taejung Kim
    • Korean Journal of Remote Sensing
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    • v.39 no.4
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    • pp.425-440
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    • 2023
  • Monitoring water surface has become one of the most prominent areas of research in addressing environmental challenges.Accurate and automated detection of watersurface in remote sensing imagesis crucial for disaster prevention, urban planning, and water resource management, particularly for a country where water plays a vital role in human life. However, achieving precise detection poses challenges. Previous studies have explored different approaches,such as analyzing water indexes, like normalized difference water index (NDWI) derived from satellite imagery's visible or infrared bands and using k-means clustering analysis to identify land cover patterns and segment regions based on similar attributes. Nonetheless, challenges persist, notably distinguishing between waterspectralsignatures and cloud shadow or terrain shadow. In thisstudy, our objective is to enhance the precision of water surface detection by constructing a comprehensive water database (DB) using existing digital and land cover maps. This database serves as an initial assumption for automated water index analysis. We utilized 1:5,000 and 1:25,000 digital maps of Korea to extract water surface, specifically rivers, lakes, and reservoirs. Additionally, the 1:50,000 and 1:5,000 land cover maps of Korea aided in the extraction process. Our research demonstrates the effectiveness of utilizing a water DB product as our first approach for efficient water surface extraction from satellite images, complemented by our second and third approachesinvolving NDWI analysis and k-means analysis. The image segmentation and binary mask methods were employed for image analysis during the water extraction process. To evaluate the accuracy of our approach, we conducted two assessments using reference and ground truth data that we made during this research. Visual interpretation involved comparing our results with the global surface water (GSW) mask 60 m resolution, revealing significant improvements in quality and resolution. Additionally, accuracy assessment measures, including an overall accuracy of 90% and kappa values exceeding 0.8, further support the efficacy of our methodology. In conclusion, thisstudy'sresults demonstrate enhanced extraction quality and resolution. Through comprehensive assessment, our approach proves effective in achieving high accuracy in delineating watersurfaces from satellite images.

A Study on Church of the stage LED lighting system equipment cases (무대영상용 LED 조명 시스템 설비의 활용 가능성에 관한 연구 - 교회의 시공사례를 중심으로)

  • Lee, Jang-Weon
    • Journal of The Korean Digital Architecture Interior Association
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    • v.11 no.3
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    • pp.61-67
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    • 2011
  • This study examined the P Church in the Large chapel and S Church in the midium chapel were Analyzed to the installed stage broadcast lighting system. As a result of the installation of lighting equipment of LED class in P Church in the Large chapel, it provided clearer image and did not have shadow. While tungsten halogen illumination was very hot and heated to be preaching, LED was not heated so the pastor was very comfortable for preaching. S Church in the Midium chapel due to low ceiling height using LED lighting musical, theater and possibly were directed. If a similar structure of Dae-Hak Street theater to replace the existing fixtures by LED lighting, rendering effective and energy saving effect is thought to have much effect.