• 제목/요약/키워드: SPOT images

검색결과 294건 처리시간 0.024초

차량의 사각 지대 제거를 위한 측/후방 카메라 영상 정합 시스템 (A Side-and Rear-View Image Registration System for Eliminating Blind Spots)

  • 박민우;장경호;정순기;윤팔주
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제36권8호
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    • pp.653-663
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    • 2009
  • 본 논문에서는 세 대의 카메라를 이용하여 사각지대를 효과적으로 제거하기 위한 파노라믹 비전 시스템(panoramic vision system)을 제안한다. 차량의 후방에는 광각 카메라를 사용하여 후방 거울(rear-view mirror)로부터 보이지 않는 사각지대를 제거하며, 나머지 두 대의 카메라는 측면 거울(side-view mirror)의 아래에 설치하여 측면 거울로 보지 못하는 사각지대를 제거한다. 좀 더 효과적인 사각지대 제거를 위해서 세 대의 카메라에서 얻어지는 영상을 정합하는 방법을 제공한다. 먼저, 후방 카메라에서 얻은 영상을 보정하고, 보정된 영상에서 focus-of-contraction(FOC)을 구한다. 그 뒤에 측방 카메라의 영상과 후방 카메라의 영상 사이의 호모그래피(homography)를 구한다. 그 다음으로 영상을 차도와 배경 영역으로 분리하고, 호모그래피를 사용하여 분리한 차도를 정합하고, 가상의 평면에 배경을 투영하여 최종정합을 완성한다. 마지막으로 정합된 영상을 보다 효과적으로 보여주기 위한 실린더 파노라마 영상, 가상의 Top-view 시스템, 그리고 차량의 다양한 정보와 함께 사각지대 영상을 보여주는 통합 정보 가시화 영상을 생성하여 제공한다.

호서 사이버 박물관: 웹기반의 파노라마 비디오 가상현실에 대한 효율적인 이미지 스티칭 알고리즘 (A proposed image stitching method for web-based panoramic virtual reality for Hoseo Cyber Museum)

  • 아르판 칸;홍성수
    • 한국산학기술학회논문지
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    • 제14권2호
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    • pp.893-898
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    • 2013
  • 파노라마 가상현실이란 특정 장소의 경험을 재현하는 방식으로, 현실 세계의 장소에 직접 가보지 않고 가상현실 속의 사물이나 정보를 보다 쉽고 빠르게 탐색하고 습득 할 수 있다. 본 논문에서는, 우리는 이상적인 키 포인트를 탐지하는 동적 프로그래밍을 사용하여 함께 이 지점과 인접한 이미지를 병합하고, 부드러운 색상 전환을 위해 이미지를 혼합하는데 사용된다. FAST와 SURF 탐지는 이미지의 확실한 특징을 찾는데 사용되고, 가장 가까운 이웃 알고리즘은 해당되는 특징을 일치시키는데 사용되며, RANSAC을 사용하여 일치하는 키 포인트를 homography로 판단한다. 이러한 방법으로 이미지를 자동 선택하여 스티칭하는 방법을 사용한다.

갑상선암 전이병소로 오인된 타석증 증례 (Sialolithiasis Mimicking Metastatic Thyroid Cancer)

  • 정환정;범희승;송호천;민정준;김성민;김지열
    • 대한핵의학회지
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    • 제34권1호
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    • pp.94-98
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    • 2000
  • We report a false positive case of I-131 scan due to a sialolithiasis in right submandibular gland. I-131 images showed not only remnant thyroid tissues and functional metastases in the anterior neck but also a hot uptake near right submandibular gland. We confirmed the sialolithiasis by radiologic studies. Sialolithiasis should be regarded as a false positive cause when I-131 scan shows a hot spot near salivary bed.

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위성영상과 삼각점조서를 이용한 비접근지역의 영상지도작성 가능성 분석 (Possibility study of Image Mapping using Triangulation Summaries in Inaccessible Area)

  • 이준혁;이승현;이영진
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2006년도 춘계학술발표회 논문집
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    • pp.133-138
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    • 2006
  • Currently high resolution satellite imagery has been used in lots of fields of terrain analysis, ocean development, change detection, cartography, classification, environmental monitoring, earth resource observation, meteorological observation as well as military The accuracy of the 3-D modeling of SPOT-5 stereopair images using these ground control points is about 5m in planimetric distance error and about 2m in height error. This study demonstrates the available ground control points for North Korea, of which accuracy is as good as to generate the digital map at the scale of 1:25,000.

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Investigation of physical sensor models for orbit modeling

  • Kim, Tae-Jung
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.217-220
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    • 2005
  • Currently, a number of control points are required in order to achieve accurate geolocation of satellite images. Control points can be generated from existing maps or surveying, or, preferably, from GPS measurements. The requirement of control points increase the cost of satellite mapping, let alone it makes the mapping over inaccessible areas troublesome. This paper investigates the possibilities of modeling an entire imaging strip with control points obtained from a small portion of the strip. We tested physical sensor models that were based on satellite orbit and attitude angles. It was anticipated that orbit modeling needed a sensor model with good accuracy of exterior orientation estimation, rather then the accuracy of bundle adjustment. We implemented sensor models with various parameter sets and checked their accuracy when applied to the scenes on the same orbital strip together with the bundle adjustment accuracy and the accuracy of estimated exterior orientation parameters. Results showed that although the models with good bundle adjustments accuracy did not always good orbit modeling and that the models with simple unknowns could be used for orbit modeling.

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MODELING SATELLITE IMAGE STRIPS WITH COLLINEARITY-BASED AND ORBIT-BASED SENSOR MODELS

  • Kim, Hyun-Suk;Kim, Tae-Jung
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.578-581
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    • 2006
  • Usually to achieve precise geolocation of satellite images, we need to get GCPs (Ground control points) from individual scenes. This requirement greatly increases the cost and processing time for satellite mapping. In this article, we focus on finding appropriate sensor models for entire image strips composing of several adjacent scenes. We tested the feasibility of modelling whole satellite image strips by establishing sensor models of one scene with GCPs and by applying the models to neighboring scenes without GCPs. For this, we developed two types of sensor models: collinearity-based type and orbit-based type and tested them using different sets of unknowns. Results indicated that although the performance of two types was very similar, for modelling individual scenes, it was not for modelling the whole strips. Moreover, the performance of sensor models was remarkably sensitive to different sets of unknowns. It was found that the orbit-based model using attitude biases as unknowns can be used to model SPOT image strips of 420 Km in length.

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충주시 중원대교 야간경관조명 계획방안에 관한 연구 (A Study on the Lighting Plan for the Jung-won bridge in Chungju City)

  • 신동인;정유근
    • KIEAE Journal
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    • 제8권4호
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    • pp.49-54
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    • 2008
  • Chungju city with beautiful natural environments and various cultural resources recently meets the new economic revival caused by opening of Jungbu Naeruk express way and invitation of the enterprise city. Now, the out door lightings come to the major issues to improve Chungju night image and to exploit new scenic spots. this study aims to develop the lighting plan for the jung-won bridge as a representative scenic spot in Chungju city. For the study, the field surveys and computer simulations were performed. As results, the lighting concepts such as entrance and apple images and alternative lighting plans were suggested.

STUDY ON THE GRID REFERENCE SYSTEM FOR KOMPSAT-3 IMAGERY

  • Kang, Chi-Ho;Ahn, Sang-Il
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.486-488
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    • 2007
  • The Grid Reference System, which was firstly used in SPOT series, has been successfully adapted in KOMPSAT-1 and KOMPSAT-2 program, which identifies the geographical location to make image collection plans and manage the database of satellite images. Each Grid Reference System for KOMPSAT-1 and KOMPSAT-2 was designed based on system parameters related to each KOMPSAT-1 and KOMPSAT-2 and this fact leads to the need for the design of the Grid Reference System for KOMPSAT-3 (KGRS-3, hereafter), which reflects system parameters for KOMPSAT-3. The (K, J) coordinate system has been defined as the Grid Reference System for KOMPSAT-3 using heritages from KOMPSAT-1 and KOMPSAT-2 programs. The numbering of K begins with the prime meridian of K = 1 with running eastward on earth increasingly, and the numbering of J uses a value of J = 1000 at all points on the equator and begin with running northward increasingly. The Grid Reference System for KOMPSAT-3 is to be implemented in Ground Segment of KOMPSAT-3 system.

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레이저 충격파 클리닝에서 발생되는 유동장의 실험적 해석 (Experimental analysis of flow field for laser shock wave cleaning)

  • 임현규;장덕석;김동식
    • 한국레이저가공학회지
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    • 제7권1호
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    • pp.29-36
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    • 2004
  • The dynamics of laser-induced plasma/shock wave and the interaction with a surface in the laser shock cleaning process are analyzed by optical diagnostics. Shock wave is generated by a Q-switched Nd:YAG laser in air or with N$_2$, Ar, and He injection into the focal spot. The shock speed is measured by monitoring the photoacoustic probe-beam deflection signal under different conditions. In addition, nanosecond time-resolved images of shock wave propagation and interaction with the substrate are obtained by the laser-flash shadowgraphy. The results reveal the effect of various operation parameters of the laser shock cleaning process on shock wave intensity, energy-conversion efficiency, and flow characteristics. Discussions are made on the cleaning mechanisms based on the experimental observations.

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More Efficient Method for Determination of Match Quality in Adaptive Least Square Matching Algorithms

  • Lee, Hae-Yeoun;Kim, Tae-Jung;Lee, Heung-Kyu
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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    • pp.274-279
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    • 1998
  • For the accurate generation of DEMs, the determination of match quality in adaptive least square matching algorithm is significantly important. Traditionally, only the degree of convergence of a solution matrix in least squares estimation has been considered for the determination of match quality. It is, however, not enough to determine the true match quality. This paper reports two approaches of match quality determination based on adaptive least square correlation : the conventional if-then logic approaches with scene geometry and correlation as additional quality measures; and, the fuzzy logic approaches. Through these, accurate decision of match quality will minimize the number of blunder and maximize the number of exact match. The proposed methods have been tested on JERS and SPOT images and the results show good performance.

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