• Title/Summary/Keyword: camera image

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RGB-LED-based Optical Camera Communication using Multilevel Variable Pulse Position Modulation for Healthcare Applications

  • Rachim, Vega Pradana;An, Jinyoung;Pham, Quan Ngoc;Chung, Wan-Young
    • Journal of Sensor Science and Technology
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    • v.27 no.1
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    • pp.6-12
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    • 2018
  • In this paper, a 32-variable pulse position modulation (32-VPPM) scheme is proposed to support a red-green-blue light-emitting-diode (RGB-LED)-based optical camera communication (OCC) system. Our proposed modulation scheme is designed to enhance the OCC data transmission rate, which is targeted for the wearable biomedical data monitoring system. The OCC technology has been utilized as an alternative solution to the radio frequency (RF) wireless system for long-term self-healthcare monitoring. Different biomedical signals, such as electrocardiograms, photoplethysmograms, and respiration signals are being monitored and transmitted wirelessly from the wearable biomedical device to the smartphone receiver. A common 30 frames per second (fps) smartphone camera with a CMOS image sensor is used to record a transmitted optical signal. Moreover, the overall proposed system architecture, modulation scheme, and data demodulation are discussed in this paper. The experimental result shows that the proposed system is able to achieve > 9 kbps using only a common smartphone camera receiver.

Development of A Prototype Device to Capture Day/Night Cloud Images based on Whole-Sky Camera Using the Illumination Data (정밀조도정보를 이용한 전천카메라 기반의 주·야간 구름영상촬영용 원형장치 개발)

  • Lee, Jaewon;Park, Inchun;cho, Jungho;Ki, GyunDo;Kim, Young Chul
    • Atmosphere
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    • v.28 no.3
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    • pp.317-324
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    • 2018
  • In this study, we review the ground-based whole-sky camera (WSC), which is developed to continuously capture day and night cloud images using the illumination data from a precision Lightmeter with a high temporal resolution. The WSC is combined with a precision Lightmeter developed in IYA (International Year of Astronomy) for analysis of an artificial light pollution at night and a DSLR camera equipped with a fish-eye lens widely applied in observational astronomy. The WSC is designed to adjust the shutter speed and ISO of the equipped camera according to illumination data in order to stably capture cloud images. And Raspberry Pi is applied to control automatically the related process of taking cloud and sky images every minute under various conditions depending on illumination data from Lightmeter for 24 hours. In addition, it is utilized to post-process and store the cloud images and to upload the data to web page in real time. Finally, we check the technical possibility of the method to observe the cloud distribution (cover, type, height) quantitatively and objectively by the optical system, through analysis of the captured cloud images from the developed device.

Depth Measurement System Using Structured Light, Rotational Plane Mirror and Mono-Camera (선형 레이저와 회전 평면경 및 단일 카메라를 이용한 거리측정 시스템)

  • Yoon Chang-Bae;Kim Hyong-Suk;Lin Chun-Shin;Son Hong-Rak;Lee Hye-Jeong
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.5
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    • pp.406-410
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    • 2005
  • A depth measurement system that consists of a single camera, a laser light source and a rotating mirror is investigated. The camera and the light source are fixed, facing the rotating mirror. The laser light is reflected by the mirror and projected to the scene objects whose locations are to be determined. The camera detects the laser light location on object surfaces through the same mirror. The scan over the area to be measured is done by mirror rotation. Advantages are 1) the image of the light stripe remains sharp while that of the background becomes blurred because of the mirror rotation and 2) the only rotating part of this system is the mirror but the mirror angle is not involved in depth computation. This minimizes the imprecision caused by a possible inaccurate angle measurement. The detail arrangement and experimental results are reported.

Precise Detection of Coplanar Checkerboard Corner Points for Stereo Camera Calibration Using a Single Frame (스테레오 카메라 캘리브레이션을 위한 동일평면 체커보드 코너점 정밀검출)

  • Park, Jeong-Min;Lee, Jong-In;Cho, Joon-Bum;Lee, Joon-Woong
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.7
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    • pp.602-608
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    • 2015
  • This paper proposes an algorithm for precise detection of corner points on a coplanar checkerboard in order to perform stereo camera calibration using a single frame. Considering the conditions of automobile production lines where a stereo camera is attached to the windshield of a vehicle, this research focuses on a coplanar calibration methodology. To obtain the accurate values of the stereo camera parameters using the calibration methodology, precise localization of a large number of feature points on a calibration target image should be ensured. To realize this demand, the idea with respect to a checkerboard pattern design and the use of a Homography matrix are provided. The calibration result obtained by the proposed method is also verified by comparing the depth information from stereo matching and a laser scanner.

3D Environment Perception using Stereo Infrared Light Sources and a Camera (스테레오 적외선 조명 및 단일카메라를 이용한 3차원 환경인지)

  • Lee, Soo-Yong;Song, Jae-Bok
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.5
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    • pp.519-524
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    • 2009
  • This paper describes a new sensor system for 3D environment perception using stereo structured infrared light sources and a camera. Environment and obstacle sensing is the key issue for mobile robot localization and navigation. Laser scanners and infrared scanners cover $180^{\circ}$ and are accurate but too expensive. Those sensors use rotating light beams so that the range measurements are constrained on a plane. 3D measurements are much more useful in many ways for obstacle detection, map building and localization. Stereo vision is very common way of getting the depth information of 3D environment. However, it requires that the correspondence should be clearly identified and it also heavily depends on the light condition of the environment. Instead of using stereo camera, monocular camera and two projected infrared light sources are used in order to reduce the effects of the ambient light while getting 3D depth map. Modeling of the projected light pattern enabled precise estimation of the range. Two successive captures of the image with left and right infrared light projection provide several benefits, which include wider area of depth measurement, higher spatial resolution and the visibility perception.

Height Measurement of Cellphone Curved Glass using Camera (카메라를 이용한 휴대폰 곡면유리의 높이측정)

  • Kim, Han-Sol;Lee, Kyung-Jun;Jung, Dong-Yean;Lee, Yeon-Hyeong;Kim, Gab-Soon
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.12
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    • pp.1002-1010
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    • 2016
  • This paper describes the design of a cellphone curved glass measuring device using by camera. The measuring device was composed of two camera, two backlight system, a body and so on, and the program was made for a camera calibration and noise removal, and also the program was made for height measurement of a cellphone curved glass using by subpixel algorism. And then a new technique for measuring the height of the cell phone curved glass was proposed. The characteristics test of height measurement of gage blocks and cell phone curved glasses was carried out, the error of the height measurement of gage block is less than ${\pm}0.005$ and the error of the height measurement of the cell phone curved glasses is less than ${\pm}0.005$. Thus it thought that the designed cellphone curved glass measuring device and the new technique for measuring the height was used to measure the height of the cellphone curved glass.

A Study On The Configuration Of UHD High Speed Digital Camera System In the Naro Space Center (나로우주센터 초고화질(UHD) 고속 디지털카메라 시스템에 대한 구성방안 연구)

  • Park, Doo-Jin;Noh, Young-Hwan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.10a
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    • pp.536-538
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    • 2017
  • UHD high speed digital camera system will be installed around launch pad and launch complex tower to acquire high speed image for motion analysis of integral parts of launch vehicle during the lift-off of KSLV-II in the Naro space center. In this paper, We compared configuration of high speed digital camera system operating in the Naro space center with UHD high speed digital camera system for mission of KSLV-II.

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Monocular Camera based Real-Time Object Detection and Distance Estimation Using Deep Learning (딥러닝을 활용한 단안 카메라 기반 실시간 물체 검출 및 거리 추정)

  • Kim, Hyunwoo;Park, Sanghyun
    • The Journal of Korea Robotics Society
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    • v.14 no.4
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    • pp.357-362
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    • 2019
  • This paper proposes a model and train method that can real-time detect objects and distances estimation based on a monocular camera by applying deep learning. It used YOLOv2 model which is applied to autonomous or robot due to the fast image processing speed. We have changed and learned the loss function so that the YOLOv2 model can detect objects and distances at the same time. The YOLOv2 loss function added a term for learning bounding box values x, y, w, h, and distance values z as 클래스ification losses. In addition, the learning was carried out by multiplying the distance term with parameters for the balance of learning. we trained the model location, recognition by camera and distance data measured by lidar so that we enable the model to estimate distance and objects from a monocular camera, even when the vehicle is going up or down hill. To evaluate the performance of object detection and distance estimation, MAP (Mean Average Precision) and Adjust R square were used and performance was compared with previous research papers. In addition, we compared the original YOLOv2 model FPS (Frame Per Second) for speed measurement with FPS of our model.

Mobile Augmented Visualization Technology Using Vive Tracker (포즈 추적 센서를 활용한 모바일 증강 가시화 기술)

  • Lee, Dong-Chun;Kim, Hang-Kee;Lee, Ki-Suk
    • Journal of Korea Game Society
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    • v.21 no.5
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    • pp.41-48
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    • 2021
  • This paper introduces a mobile augmented visualization technology that augments a three-dimensional virtual human body on a mannequin model using two pose(position and rotation) tracking sensors. The conventional camera tracking technology used for augmented visualization has the disadvantage of failing to calculate the camera pose when the camera shakes or moves quickly because it uses the camera image, but using a pose tracking sensor can overcome this disadvantage. Also, even if the position of the mannequin is changed or rotated, augmented visualization is possible using the data of the pose tracking sensor attached to the mannequin, and above all there is no load for camera tracking.

Development of Wave Height Field Measurement System Using a Depth Camera (깊이카메라를 이용한 파고장 계측 시스템의 구축)

  • Kim, Hoyong;Jeon, Chanil;Seo, Jeonghwa
    • Journal of the Society of Naval Architects of Korea
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    • v.58 no.6
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    • pp.382-390
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    • 2021
  • The present study suggests the application of a depth camera for wave height field measurement, focusing on the calibration procedure and test setup. Azure Kinect system is used to measure the water surface elevation, with a field of view of 800 mm × 800 mm and repetition rate of 30 Hz. In the optimal optical setup, the spatial resolution of the field of view is 288 × 320 pixels. To detect the water surface by the depth camera, tracer particles that float on the water and reflects infrared is added. The calibration consists of wave height scaling and correction of the barrel distortion. A polynomial regression model of image correction is established using machine learning. The measurement results by the depth camera are compared with capacitance type wave height gauge measurement, to show good agreement.