• Title/Summary/Keyword: camera image

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Proposed Schemes for Image Sensors Compatibility in IEEE TG7r1 Image Sensor Communications

  • Nguyen, Trang;Hong, Chang Hyun;Jang, Yeong Min
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.7
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    • pp.799-808
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    • 2016
  • The IEEE 802.15.7r1 Task Group (TG7r1), known as the revision of the IEEE 802.15.7 Visible Light Communication standard targeting the commercial usage of visible light communication systems which mainly use either image sensors or cameras, is of interest in this paper. The vast challenge in Image Sensor Communications (ISC), as it has been addressed in the Technical Consideration Document (TCD) of the TG7r1, is the Image Sensor Compatibility to support the variety of different commercial cameras available on the market. The on-going ISC standard must adhere to compatible image sensors regulations. This paper brings an inside review of the TG7r1 and an inside look of related works on Image Sensor Communications. The paper analyzes the compatibility features by introducing a revised model of receiver to explain how those features are necessary. One of the most challenging but interesting features is the capability in being compatible to camera frame rates. The variation of camera frame rate is modeled from verified experimental results. Noticeably, three singular approaches to support frame rates compatibility, including temporal approach, spatial approach, and frequency-domain approach, are proposed on the paper along with concise definitions. Those schemes have been presented as valuable proposals on the call-for-proposal meeting series of the TG7r1 recently.

Epipolar Resampling for High Resolution Satellite Imagery Based on Parallel Projection (평행투영 기반의 고해상도 위성영상 에피폴라 재배열)

  • Noh, Myoung-Jong;Cho, Woo-Sug;Chang, Hwi-Jeong;Jeong, Ji-Yeon
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.4
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    • pp.81-88
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    • 2007
  • The geometry of satellite image captured by linear CCD sensor is different from that of frame camera image. The fact that the exterior orientation parameters for satellite image with linear CCD sensor varies from scan line by scan line, causes the difference of image geometry between frame and linear CCD sensor. Therefore, we need the epipolar geometry for linear CCD image which differs from that of frame camera image. In this paper, we proposed a method of resampling linear CCD satellite image in epipolar geometry under the assumption that image is not formed in perspective projection but in parallel projection, and the sensor model is a 2D affine sensor model based on parallel projection. For the experiment, IKONOS stereo images, which are high resolution linear CCD images, were used and tested. As results, the spatial accuracy of 2D affine sensor model is investigated and the accuracy of epipolar resampled image with RFM was presented.

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Sequence Images Registration by using KLT Feature Detection and Tracking (KLT특징점 검출 및 추적에 의한 비디오영상등록)

  • Ochirbat, Sukhee;Park, Sang-Eon;Shin, Sung-Woong;Yoo, Hwan-Hee
    • Journal of Korean Society for Geospatial Information Science
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    • v.16 no.2
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    • pp.49-56
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    • 2008
  • Image registration is one of the critical techniques of image mosaic which has many applications such as generating panoramas, video monitoring, image rendering and reconstruction, etc. The fundamental tasks of image registration are point features extraction and tracking which take much computation time. KLT(Kanade-Lucas-Tomasi) feature tracker has proposed for extracting and tracking features through image sequences. The aim of this study is to demonstrate the usage of effective and robust KLT feature detector and tracker for an image registration using the sequence image frames captured by UAV video camera. In result, by using iterative implementation of the KLT tracker, the features extracted from the first frame of image sequences could be successfully tracked through all frames. The process of feature tracking in the various frames with rotation, translation and small scaling could be improved by a careful choice of the process condition and KLT pyramid implementation.

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Automated Image Alignment and Monitoring Method for Efficient Stereoscopic 3D Contents Production (스테레오스코픽 3D 콘텐츠 제작의 효율성 향상을 위한 자동 영상정렬 및 모니터링 기법)

  • Kim, Jae-In;Kim, Taejung
    • Journal of Broadcast Engineering
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    • v.19 no.2
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    • pp.205-214
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    • 2014
  • Minimization of visual fatigue is important for production of high quality stereoscopic 3D contents. Vertical disparity of stereo images occurred during contents production is considered as the main factor of visual fatigue. To ensure correct stereoscopy vertical disparity needs to be eliminated. In this paper, a method for automated image alignment was proposed for Stereoscopic 3D contents generation and post-processing steps. The proposed method consists of two parts: rectification for image alignment and camera motion detection. The proposed method showed that its rectification performance was the most superior among the existing methods tested and that camera motion detection had a success rate of 98.35%. Through these evaluations, we confirmed that the proposed method can be effectively applied to 3D contents production.

Stereo cameras calibration bases on Epipolar Rectification and its Application

  • Chaewieang, Pipat;Thepmanee, Teerawat;Kummool, Sart;Jaruvanawat, Anuchit;Sirisantisamrid, Kaset
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.246-249
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    • 2003
  • The constraints necessary guarantee using the comparison of these extrinsic parameters, which each Rotation matrix and Translation Vector must be equal to the either, except the X-axis Translation Vector. Thus, we can not yet calculate the 3D-range measurement in the end of camera calibration. To minimize this disadvantage, the Epipolar Rectification has been proposed in the literature. This paper aims to present the development of Epipolar Rectification to calibrate Stereo cameras. The required computation of the transformation mapping between points in 3D-space is based on calculating the image point that appears on new image plane by using calibrated parameters. This computation is assumed from the rotating the old ones around their optical center until focal planes becomes coplanar, thereby containing the baseline, and the Z-axis of both camera coordinate to be parallel together. The optical center positions of the new extrinsic parameters are the same as the old camera, whereas the new orientation differs from the old ones by the suitable rotations. The intrinsic parameters are the same for both cameras. So that, after completed calibration process, immediately can calculate the 3D-range measurement. And the rectification determines a transformation of each image plane such that pairs of conjugate Epipolar lines become collinear and parallel to one of the image axis. From the experimental results verify the proposed technique are agreed with the expected specifications.

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Using Camera Tracking and Image Composition Technique in Visual Effect Imaginary Production (시각효과 영상제작에서 카메라 추적과 영상합성 기술의 활용)

  • Kim, Myung-Ha;Yu, Jung-Jae;Hong, Hyun-Ki
    • The Journal of the Korea Contents Association
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    • v.11 no.6
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    • pp.135-143
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    • 2011
  • Visual effect production by computer graphics techniques has become more important in these days. However, there are three problems in the domestic contents production environments. First of all, most Korean film companies have insufficient generally potential to maintain and support their R&D (Research and Development) teams. Secondly, they are much dependent on the abroad commercial software tools. Finally, many people have to participate in the image production pipeline, called the labor-intensive pipeline. In producing a demonstration work, "The Sixty -miles-an-hour man", we have evaluated the usefulness of the developed camera tracking and image composition methods and then examined various production consideration elements. In addition, in order to develop a productive technical element and write a competitive film script, mutual understanding between the developers and the production users should be achieved. Also, this paper describes a role of the technical supervisor to direct the production environment in detail.

Measurement of Target Objects Based on Recognition of Curvature and Plane Surfaces using a Single Slit Beam Projection (슬릿광 투영법을 이용한 곡면과 평면의 식별에 의한 대상물체의 계측)

  • Choi, Yong-Woon;Kim, Young-Bok
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.5
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    • pp.568-576
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    • 1999
  • Using a laser sheet beam projector combined with a CCD-Camera, an efficient technique to recognize complex surface of curvature and lane has been demonstrated for the purpose of mobile robot navigation. In general, obstacles of indoor environments in the field of SLIT-RAY plane are captured as segments of an elliptical arc and a line in the camera image. The robot has been capable of moving along around the obstacle in front of it, by recognizing the original shape of each segment with the differential coefficient by means of least squares method. In this technique, the imaged pixels of each segment, particularly elliptical arc, have been converted into a corresponding circular arc in the real-world coordinates so as to make more feasible the image processing for the position and radius measurement than conventional way based on direct elliptical are analyses. Advantages over direct elliptical cases include 1) higher measurement accuracy and shorter processing time because the circular arc process can reduce the shape-specifying parameters, 2) no complicated factor such as the tilt of elliptical arc axis in the image plane, which produces the capability to find column position and radiua regardless of the camera location . These are essentially required for a mobile robot application. This technique yields an accuracy less than 2cm for a 28.5cm radius column located in the range of 70-250cm distance from the robot. The accuracy obtained in this study is sufficient enough to navigate a cleaning robot which operates in indoor environments.

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Simultaneous velocity and temperature measurement of thermo-fluid flows by using particle imaging technique (화상처리기법을 이용한 온도장 및 속도장 동시 측정기법 개발)

  • Lee, Sang-Joon;Baek, Seung-Jo;Yoon, Jong-Hwan;Doh, Deog-Hee
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.10
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    • pp.3334-3343
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    • 1996
  • A quantitative flow visualization technique was developed to measure velocity and temperature fields simultaneously in a two-dimensional cross section of thermo-fluid flows. Thermochromic liquid crystal(TLC) particles are used as temperature sensor and velocity tracers. Illuminating a thermo-fluid flow with a thin sheet of white light, the reflected colors from the TLC particles in the flow were captured simultaneously by two CCD cameras; a 3-chip CCD color camera for temperature field measurement and a black and white CCD camera for velocity field measurement. Variations of temperature field were measured by using a HSI true color image processing system and TLC solution. The relationship between the hue values of TLC color image and real temperature was obtained and this calibration curve was used to measure the true temperature under the same camera and illumination condition. The velocity field was obtained by using a 2-frame PTV technique using the concept of match-probability to track true velocity vectors from two consecutive image frames. These two techniques were applied at the same time to the unsteady thermal-fluid flow in a Hele-Shaw cell to measure the temperature and velocity field simultaneously and some results are discussed.

Analysis of Visible Light Communication Module Degraded by High Dose-Rate Gamma Irradiation using Thermal Infrared Image (적외선 열영상을 이용한 가시광 통신모듈의 고선량 감마선조사에 따른 열화 분석)

  • Cho, Jai-Wan;Hong, Seok-Boong;Koo, In-Soo
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.12
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    • pp.1203-1209
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    • 2011
  • In this paper, the degradation evaluation method of VLC (Visible Light Communication) wireless module after high dose rate gamma-ray irradiation using the thermal infrared camera is proposed. First, the heating characteristics of the active devices embedded in the VLC wireless module during the condition of normal operation is monitored by thermal infrared camera. By the image processing technique, the trends of the intensity of the heat emitted by the active devices are calculated and stored. The feature of the blob area including the area of the active devices in the thermal infrared image is extracted and stored. The feature used in this paper is the mean value of the gray levels in the blob area. The same VLC module has been gamma irradiated at the dose rate of about 4.0 kGy/h during 72 hours up to a total dose of 288 kGy. And then, the heating characteristics of the active devices embedded in the VLC wireless module after high dose gamma ray irradiation is observed by thermal infrared camera. The high dose gamma-ray induced degradation of the active devices embedded in the VLC module was evaluated by comparing the mean value of the blob area to the one of the same blob area of the VLC module before the gamma ray irradiation.

Real-time Implementation and Application of Pointing Region Estimation System using 3D Geometric Information in Real World (실세계 3차원 기하학 정보를 이용한 실시간 지시영역 추정 시스템의 구현 및 응용)

  • Han, Yun-Sang;Seo, Yung-Ho;Doo, Kyoung-Soo;Kim, Jin-Tae;Choi, Jong-Soo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.2
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    • pp.29-36
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    • 2008
  • In this paper we propose a real-time method to estimate a pointing region from two camera images. In general, a pointing target exists in the face direction when a human points to something. Therefore, we regard the direction of pointing as the straight line that connects the face position with the fingertip position. First, the method extracts two points in the face and the fingertips region by using detecting the skin color of human being. And we used the 3D geometric information to obtain a pointing detection and its region. In order to evaluate the performance, we have build up an ICIGS(Interactive Cinema Information Guiding System) with two camera and a beam project.