• Title/Summary/Keyword: multiview

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Intermediate Image Generation based on Disparity Path Search in Block of Disparity Space Image (시차공간영상에서의 구간별 시차 경로 탐색을 이용한 중간 영상 생성)

  • Kwak, Ji-Hyun;Kim, Kyung-Tae
    • The KIPS Transactions:PartB
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    • v.15B no.1
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    • pp.9-16
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    • 2008
  • In this paper, we present an algorithm for synthesizing intermediate view image from a stereoscopic pair of images. An image of multiview is need for people in order to easily recognize 3D image. However, if many cameras are use for that, not only does system get more complicated but also transmission rating cause a big trouble. Hence, stereo images are photograph and issue on the sending side and algorithm to generate several intermediate view image is able to be use on the receiving side. The proposed method is based on disparity space image. First of all, disparity space image that is depicted by the gap of pixel followed by disparity of stereo image is generated. Disparity map is made by utilizing disparity space image for searching for optimal disparity path then eventual intermediate view image is generated after occlusion region which does not match is processed. Experimental results illustrate the performance of the proposed technique and we obtained a high quality image of more than 30 dB PSNR.

Factors Clustering Approach to Parametric Cost Estimates And OLAP Driver

  • JaeHo, Cho;BoSik, Son;JaeYoul, Chun
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.707-716
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    • 2009
  • The role of cost modeller is to facilitate the design process by systematic application of cost factors so as to maintain a sensible and economic relationship between cost, quantity, utility and appearance which thus helps in achieving the client's requirements within an agreed budget. There are a number of research on cost estimates in the early design stage based on the improvement of accuracy or impact factors. It is common knowledge that cost estimates are undertaken progressively throughout the design stage and make use of the information that is available at each phase, through the related research up to now. In addition, Cost estimates in the early design stage shall analyze the information under the various kinds of precondition before reaching the more developed design because a design can be modified and changed in all process depending on clients' requirements. Parametric cost estimating models have been adopted to support decision making in a changeable environment, in the early design stage. These models are using a similar instance or a pattern of historical case to be constituted in project information, geographic design features, relevant data to quantity or cost, etc. OLAP technique analyzes a subject data by multi-dimensional points of view; it supports query, analysis, comparison of required information by diverse queries. OLAP's data structure matches well with multiview-analysis framework. Accordingly, this study implements multi-dimensional information system for case based quantity data related to design information that is utilizing OLAP's technology, and then analyzes impact factors of quantity by the design criteria or parameter of the same meaning. On the basis of given factors examined above, this study will generate the rules on quantity measure and produce resemblance class using clustering of data mining. These sorts of knowledge-base consist of a set of classified data as group patterns, of which will be appropriate stand on the parametric cost estimating method.

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New Prefiltering Methods based on a Histogram Matching to Compensate Luminance and Chrominance Mismatch for Multi-view Video (다시점 비디오의 휘도 및 색차 성분 불일치 보상을 위한 히스토그램 매칭 기반의 전처리 기법)

  • Lee, Dong-Seok;Yoo, Ji-Sang
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.6
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    • pp.127-136
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    • 2010
  • In multi-view video, illumination disharmony between neighboring views can occur on account of different location of each camera and imperfect camera calibration, and so on. Such discrepancy can be the cause of the performance decrease of multi-view video coding by mismatch of inter-view prediction which refer to the pictures obtained from the neighboring views at the same time. In this paper, we propose an efficient histogram-based prefiltering algorithm to compensate mismatches between the luminance and chrominance components in multi-view video for improving its coding efficiency. To compensate illumination variation efficiently, all camera frames of a multi-view sequence are adjusted to a predefined reference through the histogram matching. A Cosited filter that is used for chroma subsampling in many video encoding schemes is applied to each color component prior to histogram matching to improve its performance. The histogram matching is carried out in the RGB color space after color space converting from YCbCr color space. The effective color conversion skill that has respect to direction of edge and range of pixel value in an image is employed in the process. Experimental results show that the compression ratio for the proposed algorithm is improved comparing with other methods.

Object VR-based 2.5D Virtual Textile Wearing System : Viewpoint Vector Estimation and Textile Texture Mapping (오브젝트 VR 기반 2.5D 가상 직물 착의 시스템 : 시점 벡터 추정 및 직물 텍스쳐 매핑)

  • Lee, Eun-Hwan;Kwak, No-Yoon
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.19-26
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    • 2008
  • This paper is related to a new technology allowing a user to have a 360 degree viewpoint of the virtual wearing object, and to an object VR(Virtual Reality)-based 2D virtual textile wearing system using viewpoint vector estimation and textile texture mapping. The proposed system is characterized as capable of virtually wearing a new textile pattern selected by the user to the clothing shape section segmented from multiview 2D images of clothes model for object VR, and three-dimensionally viewing its virtual wearing appearance at a 360 degree viewpoint of the object. Regardless of color or intensity of model clothes, the proposed system is possible to virtually change the textile pattern with holding the illumination and shading properties of the selected clothing shape section, and also to quickly and easily simulate, compare, and select multiple textile pattern combinations for individual styles or entire outfits. The proposed system can provide higher practicality and easy-to-use interface, as it makes real-time processing possible in various digital environment, and creates comparatively natural and realistic virtual wearing styles, and also makes semi -automatic processing possible to reduce the manual works to a minimum. According to the proposed system, it can motivate the creative activity of the designers with simulation results on the effect of textile pattern design on the appearance of clothes without manufacturing physical clothes and, as it can help the purchasers for decision-making with them, promote B2B or B2C e-commerce.

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Robust Semi-auto Calibration Method for Various Cameras and Illumination Changes (다양한 카메라와 조명의 변화에 강건한 반자동 카메라 캘리브레이션 방법)

  • Shin, Dong-Won;Ho, Yo-Sung
    • Journal of Broadcast Engineering
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    • v.21 no.1
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    • pp.36-42
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    • 2016
  • Recently, many 3D contents have been produced through the multiview camera system. In this system, since a difference of the viewpoint between color and depth cameras is inevitable, the camera parameter plays the important role to adjust the viewpoint as a preprocessing step. The conventional camera calibration method is inconvenient to users since we need to choose pattern features manually after capturing a planar chessboard with various poses. Therefore, we propose a semi-auto camera calibration method using a circular sampling and an homography estimation. Firstly, The proposed method extracts the candidates of the pattern features from the images by FAST corner detector. Next, we reduce the amount of the candidates by the circular sampling and obtain the complete point cloud by the homography estimation. Lastly, we compute the accurate position having the sub-pixel accuracy of the pattern features by the approximation of the hyper parabola surface. We investigated which factor affects the result of the pattern feature detection at each step. Compared to the conventional method, we found the proposed method released the inconvenience of the manual operation but maintained the accuracy of the camera parameters.

New Illumination compensation algorithm improving a multi-view video coding performance by advancing its temporal and inter-view correlation (다시점 비디오의 시공간적 중복도를 높여 부호화 성능을 향상시키는 새로운 조명 불일치 보상 기법)

  • Lee, Dong-Seok;Yoo, Ji-Sang
    • Journal of Broadcast Engineering
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    • v.15 no.6
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    • pp.768-782
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    • 2010
  • Because of the different shooting position between multi-view cameras and the imperfect camera calibration, Illumination mismatches of multi-view video can happen. This variation can bring about the performance decrease of multi-view video coding(MVC) algorithm. A histogram matching algorithm can be applied to recompensate these inconsistencies in a prefiltering step. Once all camera frames of a multi-view sequence are adjusted to a predefined reference through the histogram matching, the coding efficiency of MVC is improved. However the histogram distribution can be different not only between neighboring views but also between sequential views on account of movements of camera angle and some objects, especially human. Therefore the histogram matching algorithm which references all frames in chose view is not appropriate for compensating the illumination differences of these sequence. Thus we propose new algorithms both the image classification algorithm which is applied two criteria to improve the correlation between inter-view frames and the histogram matching which references and matches with a group of pictures(GOP) as a unit to advance the correlation between successive frames. Experimental results show that the compression ratio for the proposed algorithm is improved comparing with the conventional algorithms.

Application of Adaptive Loop Filter for NRT-Based Stereoscopic Video Coding (비실시간 기반 스테레오스코픽 비디오 부호화를 위한 적응루프필터 적용기법)

  • Lee, Byung-Tak;Lee, BongHo;Choi, Haechul;Kim, Jin-Soo;Yun, Kugjin;Cheong, Won-Sik;Kim, Jae-Gon
    • Journal of Broadcast Engineering
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    • v.18 no.2
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    • pp.261-270
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    • 2013
  • A stereoscopic 3D video service is able to provide a 3D video service while keeping backward compatibility with the existing 2D video service. In the terrestrial digital television (DTV) system, a stereoscopic video codec is required to have high coding efficiency in order to provide a 3D video service in the same channel capacity. A hybrid codec consisting of MPEG-2 for base video and H.264/AVC or HEVC for 3D auxiliary video is considered. Furthermore, Non-Real-Time (NRT) delivery of stereoscopic video is also considered as a service scenario for 3DTV services to overcome the limited bandwidth. In this paper, we propose a stereoscopic video coding scheme using adaptive loop filter (ALF) which had been considered in HEVC as a pre-/post-filter for enhancing coding efficiency in NRT-based 3DTV services. In order to apply ALF as a post-filter to the reconstructed additional view coded by H.264/AVC, we devise a method in which ALF is adaptively applied based on a structure determined by using macroblock (MB) coding information such as MB mode type and reference index instead of coding unit (CU) structure on which ALF is applied in the HEVC. Experimental results shows that the proposed stereoscopic video coding scheme applying ALF obtains up to 24.9% gain of bit saving.

Multiple Camera Based Imaging System with Wide-view and High Resolution and Real-time Image Registration Algorithm (다중 카메라 기반 대영역 고해상도 영상획득 시스템과 실시간 영상 정합 알고리즘)

  • Lee, Seung-Hyun;Kim, Min-Young
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.49 no.4
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    • pp.10-16
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    • 2012
  • For high speed visual inspection in semiconductor industries, it is essential to acquire two-dimensional images on regions of interests with a large field of view (FOV) and a high resolution simultaneously. In this paper, an imaging system is newly proposed to achieve high quality image in terms of precision and FOV, which is composed of single lens, a beam splitter, two camera sensors, and stereo image grabbing board. For simultaneously acquired object images from two camera sensors, Zhang's camera calibration method is applied to calibrate each camera first of all. Secondly, to find a mathematical mapping function between two images acquired from different view cameras, the matching matrix from multiview camera geometry is calculated based on their image homography. Through the image homography, two images are finally registered to secure a large inspection FOV. Here the inspection system of using multiple images from multiple cameras need very fast processing unit for real-time image matching. For this purpose, parallel processing hardware and software are utilized, such as Compute Unified Device Architecture (CUDA). As a result, we can obtain a matched image from two separated images in real-time. Finally, the acquired homography is evaluated in term of accuracy through a series of experiments, and the obtained results shows the effectiveness of the proposed system and method.

Illumination Mismatch Compensation Algorithm based on Layered Histogram Matching by Using Depth Information (깊이 정보에 따른 레이어별 히스토그램 매칭을 이용한 조명 불일치 보상 기법)

  • Lee, Dong-Seok;Yoo, Ji-Sang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.8C
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    • pp.651-660
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    • 2010
  • In this paper, we implement an efficient histogram-based prefiltering to compensate the illumination mismatches in regions between neighboring views. In multi-view video, such illumination disharmony can primarily occur on account of different camera location and orientation and an imperfect camera calibration. This discrepancy can cause the performance decrease of multi-view video coding(MVC) algorithm. A histogram matching algorithm can be exploited to make up for these differences in a prefiltering step. Once all camera frames of a multi-view sequence are adjusted to a predefined reference through the histogram matching, the coding efficiency of MVC is improved. However general frames of multi-view video sequence are composed of several regions with different color composition and their histogram distribution which are mutually independent of each other. In addition, the location and depth of these objects from sequeuces captured from different cameras can be different with different frames. Thus we propose a new algorithm which classify a image into several subpartitions by its depth information first and then histogram matching is performed for each region individually. Experimental results show that the compression ratio for the proposed algorithm is improved comparing with the conventional image-based algorithms.