• Title/Summary/Keyword: Digital Camera

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Non-Metric Digital Camera Lens Calibration Using Ground Control Points (지상기준점을 이용한 비측량용 카메라 렌즈 캘리브레이션)

  • Won, Jae-Ho;So, Jae-Kyeong;Yun, Hee-Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.30 no.2
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    • pp.173-180
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    • 2012
  • The most recent, 80 mega pixels digital camera appeared through the development of digital technology, and nonmetric digital cameras have been using in various field of photogrammetry. In this study, we experimented lens calibration using aerial photographs and ground control points. The aerial photographs were taken a non-metric digital camera which is CMOS(Complementary Metal Oxide Semiconductor) 21.1 mega pixels sensor and 35mm lens at a helicopter. And the ground control points were selected on the 1:1,000 plotting origin data. As a result, we calculated focal length, PPA(Principal Point of Autocollimation) and symmetric radial distortion coefficients from the lens. Also, RMSE(root mean square error) and maximum residual of the ground control points from the aerial triangulation were compared before and after calibration. And we found that the accuracy of the after calibration was improved very significantly.

Reconstruction of body contour with digital camera image (Digital Camera의 영상을 이용한 신체 단면도 제작)

  • Kwon, KT;Kim, CM;Kang, TY;Park, CS;Song, HK
    • The Journal of Korean Society for Radiation Therapy
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    • v.15 no.1
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    • pp.53-60
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    • 2003
  • I. Purpose It is essential to have the correct body contour information for the calculation of dose distribution. The role of CT images in the radiation oncology field has been increased. But there still exists a method to use cast or lead wire for the body contour drawing. This traditional method has drawbacks such as in accurate and time consuming procedure. This study has been designed to overcome this problem. II. Materials and Methods A digital camera is attached to a pole which stands on the opposite side of the gantry. Positional information was acquired from an image of the phantom which is specially designed for this study and located on the isocenter level of the simulator Laser line on the patients skin or on the phantom surface was digitized and reconstructed as the contour. Verification of usefulness this technique has been done with various shape of phantoms and a patients chest III. Results and Conclusions Contours from the traditional method with the cast or lead wire and the digital image method showed good agreement within experimetal error range. This technique showed more efficiente in time and convenience. For irregular shaped contour, like H&N region, special care are needed. The results suggest that more study is needed. To use of the another photogrammatory techinique with two camera system may be better for the actual clinical application

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Analysis of Coupling Between Digital Noise and Portable Smart Terminal Antenna According to Antenna Types (휴대용 스마트 단말기 안테나 타입에 따른 디지털 노이즈와 안테나의 결합 분석)

  • Kim, Joonchul
    • Journal of IKEEE
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    • v.23 no.3
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    • pp.873-877
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    • 2019
  • In this paper, we analyze the degree of digital noise coupling for Inverted F Antenna (IFA) and Loop Antenna, which are representative types of portable terminal antenna, using characteristic mode. Firstly, the degree of coupling according to the direction of digital signal lines and characteristic mode current of the printed circuit board (PCB) including the antenna is compared and analyzed, and based on this result, the coupling between WiFi antenna and the front camera noise is analyzed. For analysis, the digital signal line and ground line of the FPCB of the camera module are modeled as a loop feeder that excites the characteristic mode of the PCB ground and the change of noise coupling according to the antenna types are analyzed.

An HDTV-Compatible 3DTV Broadcasting System

  • Hur, Nam-Ho;Lee, Gwang-Soon;You, Woong-Shik;Lee, Jin-Hwan;Ahn, Chung-Hyun
    • ETRI Journal
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    • v.26 no.2
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    • pp.71-82
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    • 2004
  • We introduce a high-definition three-dimensional television (3DTV) broadcasting system that is fully compatible with the existing transmission system of high-definition television (HDTV). Specifically, we developed high-definition 3DTV broadcasting subsystems including a 3DTV camera, 3DTV video multiplexer and demultiplexer, 3DTV receiver, and 3DTV outdoor broadcast van. To verify the developed subsystems, we performed experimental services of 3DTV broadcasting during the 2002 FIFA World Cup Korea/Japan. According to our subjective evaluation test, 88% of 273 viewers rated the perceived depth of 3DTV as “Good,” and 36% of the viewers preferred 3DTV to other digital broadcasting services.

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A Design of Stand-Alone Linescan Camera Framegrabber Based on FPGA (FPGA 기반의 독립형 라인스캔 카메라 프레임그래버 설계)

  • Jeong, Heon;Choi, Han-Soo
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.12
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    • pp.1036-1040
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    • 2002
  • To process data of digital linescan camera, the frame grabber is essential to handle the data in low-level and in high speed more than 30 MHz stably. Traditional approaches to the development of hardware in vision system for the special purpose are mai y based on PC system, and are expensive and gigantic. Therefore, there are many difficulties in applying those in the field. So we investigate, in this paper, the implementation of FPGA for real-time processing of digital linescan camera. The system is not based on PC, but electronic device such as micropncessor. So it is expected that the use of FPGAs for low-level processing represents a fast, stable and inexpensive system. The experiments are carried out on the web guiding system in order to show the efficiency of the new image processor.

Modal Parameter Extraction Using a Digital Camera (디지털 카메라를 이용한 구조물의 동특성 추출)

  • Kim, Byeong-Hwa
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.11a
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    • pp.61-68
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    • 2008
  • A set of modal parameters of a stay-cable have been extracted from a moving picture captured by a digital camera supported by shaking hands. It is hard to identify the center of targets attached on the cable surface from the blurred cable motion image, because of the high speed motion of cable, low sampling frequency of camera, and the shaking effect of camera. This study proposes a multi-template matching algorithm to resolve such difficulties. In addition, a sensitivity-based system identification algorithm is introduced to extract the natural frequencies and damping ratios from the ambient cable vibration data. Three sets of vibration tests are conducted to examine the validity of the proposed algorithms. The results show that the proposed technique is pretty feasible for extracting modal parameters from the severely shaking motion pictures.

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Development of Inspection System for Aluminum Castings with X-Ray TDI Camera (X-Ray TDI Camera를 이용한 알루미늄 주강품 검사장치 개발)

  • Nam, Mun-Ho;Park, Seong-Wook;Kim, Chang-Ho;Chung, Chan-Soo
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1734-1735
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    • 2011
  • In case of inspection on aluminum castings, traditional RT (Radiographic Testing) method have been utilized for its advantages in interpretation, cost and perpetual storage. But it has disadvantages like time consumption in film processing, low efficiency in storage and environmental pollution. In this thesis, a DRS (Digital Radiography System) utilizing X-Ray TDI Camera (Time Delay and Integration Camera) is developed. Inspections on aluminum castings are performed using the developed Digital Radiography System, DRS and reviewed if newly developed system can substitute for the traditional method.

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Analysis of convergent looking stereo camera model (교차 시각 스테레오 카메라 모델 해석)

  • 이적식
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.10
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    • pp.50-62
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    • 1996
  • A parallel looking stereo camera was mainly used as an input sensor for digital image processing, image understanding and the extraction of 3 dimensional information. Theoretical analysis and performance evaluation are dealt in this paper for a convergent looking stereo camera model having a fixation point with the result of crossing optical axes. The quantization error, depth resolution and equidepth map due to digital pixels, and the misalignments effects of pan, tilt and roll angles are analyzed by using rhe relationship between the reference and image coordinate systems. Also horopter, epipolar lines, probability density functions of the depth error, and stereo fusion areas for the two camera models are discussed.

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Modal Parameter Extraction Using a Digital Camera (카메라를 이용한 구조물의 동특성 추출)

  • Kim, Byeong-Hwa
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.12
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    • pp.1229-1236
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    • 2008
  • A set of modal parameters of a stay-cable have been extracted fi:on a moving picture captured by a digital camera supported by shaking hands. It is hard to identify the center of targets attached on the cable surface from the blurred cable motion image, because of the high speed motion of cable, low sampling frequency of camera, and the shaking effect of camera. This study proposes a multi-template matching algorithm to resolve such difficulties. In addition, a sensitivity-based system identification algorithm is introduced to extract the natural frequencies and damping ratios from the ambient cable vibration data. Three sets of vibration tests are conducted to examine the validity of the proposed algorithms. The results show that the proposed technique is pretty feasible for extracting modal parameters from the severely shaking motion pictures.

Proposal of 3D Camera-Based Digital Coordinate Recognition Technology (3D 카메라 기반 디지털 좌표 인식 기술 제안)

  • Koh, Jun-Young;Lee, Kang-Hee
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2022.07a
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    • pp.229-230
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    • 2022
  • 본 논문에서는 CNN Object Detection과 더불어 3D 카메라 기반 디지털 좌표 인식 기술을 제안한다. 이 기술은 3D Depth Camera인 Intel 사의 Realsense D455를 이용해 대상을 감지하고 분류하며 대상의 위치를 파악한다. 또한 이 기술은 기존의 Depth Camera 내장 거리와는 다르게 좌표를 인식하여 좌표간의 거리까지 계산이 가능하다. 또한 Tensorflow SSD 구조와의 메모리 공유를 통해 시스템의 자원 낭비를 줄이며, 속도를 높이는 멀티쓰레드를 탑재했다. 본 기술을 통해 좌표간의 거리를 계산함으로써 스포츠, 심리, 놀이, 산업 등 다양한 환경에서 활용할 수 있다.

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