• Title/Summary/Keyword: Various lighting conditions

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Real-Time Eye Detection and Tracking Under Various Light Conditions (다양한 조명하에서 실시간 눈 검출 및 추적)

  • 박호식;박동희;남기환;한준희;나상동;배철수
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.227-232
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    • 2003
  • Non-intrusive methods based on active remote IR illumination for eye tracking is important for many applications of vision-based man-machine interaction. One problem that has plagued those methods is their sensitivity to lighting condition change. This tends to significantly limit their scope of application. In this paper, we present a new real-time eye detection and tracking methodology that works under variable and realistic lighting conditions. eased on combining the bright-pupil effect resulted from IR light and the conventional appearance-based object recognition technique, our method can robustly track eyes when the pupils are not very bright due to significant external illumination interferences. The appearance model is incorporated in both eyes detection and tracking via the use of support vector machine and the mean shift tracking. Additional improvement is achieved from modifying the image acquisition apparatus including the illuminator and the camera.

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Neural Relighting using Specular Highlight Map (반사 하이라이트 맵을 이용한 뉴럴 재조명)

  • Lee, Yeonkyeong;Go, Hyunsung;Lee, Jinwoo;Kim, Junho
    • Journal of the Korea Computer Graphics Society
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    • v.26 no.3
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    • pp.87-97
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    • 2020
  • In this paper, we propose a novel neural relighting that infers a relighted rendering image based on the user-guided specular highlight map. The proposed network utilizes a pre-trained neural renderer as a backbone network learned from the rendered image of a 3D scene with various lighting conditions. We jointly optimize a 3D light position and its associated relighted image by back-propagation, so that the difference between the base image and the relighted image is similar to the user-guided specular highlight map. The proposed method has the advantage of being able to explicitly infer the 3D lighting position, while providing the artists' preferred 2D screen-space interface. The performance of the proposed network was measured under the conditions that can establish ground truths, and the average error rate of light position estimations is 0.11, with the normalized 3D scene size.

Synthesis of Realistic Facial Expression using a Nonlinear Model for Skin Color Change (비선형 피부색 변화 모델을 이용한 실감적인 표정 합성)

  • Lee Jeong-Ho;Park Hyun;Moon Young-Shik
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.43 no.3 s.309
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    • pp.67-75
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    • 2006
  • Facial expressions exhibit not only facial feature motions, but also subtle changes in illumination and appearance. Since it is difficult to generate realistic facial expressions by using only geometric deformations, detailed features such as textures should also be deformed to achieve more realistic expression. The existing methods such as the expression ratio image have drawbacks, in that detailed changes of complexion by lighting can not be generated properly. In this paper, we propose a nonlinear model for skin color change and a model-based synthesis method for facial expression that can apply realistic expression details under different lighting conditions. The proposed method is composed of the following three steps; automatic extraction of facial features using active appearance model and geometric deformation of expression using warping, generation of facial expression using a model for nonlinear skin color change, and synthesis of original face with generated expression using a blending ratio that is computed by the Euclidean distance transform. Experimental results show that the proposed method generate realistic facial expressions under various lighting conditions.

Visible Light Communication with Color and Brightness Control of RGB LEDs

  • Choi, Kyungmook;Jang, Yunseon;Ju, MinChul;Park, Youngil
    • ETRI Journal
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    • v.35 no.5
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    • pp.927-930
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    • 2013
  • We propose a visible light communication system in which the color and brightness are controllable. Pulse width modulation and variable pulse position modulation (VPPM) schemes are used to control the color and brightness, respectively. A digital algorithm to decode VPPM signals is suggested and implemented. A seamless transmission is observed in a testbed experiment under various environmental conditions. The proposed scheme can be applied to emotional-lighting-based wireless optical communication.

A Fuzzy Neural-Network Algorithm for Noisiness Recognition of Road Images (도로영상의 잡음도 식별을 위한 퍼지신경망 알고리즘)

  • 이준웅
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.5
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    • pp.147-159
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    • 2002
  • This paper proposes a method to recognize the noisiness of road images connected with the extraction of lane-related information in order to prevent the usage of erroneous information. The proposed method uses a fuzzy neural network(FNN) with the back-Propagation loaming algorithm. The U decides road images good or bad with respect to visibility of lane marks on road images. Most input parameters to the FNN are extracted from an edge distribution function(EDF), a function of edge histogram constructed by edge phase and norm. The shape of the EDF is deeply correlated to the visibility of lane marks of road image. Experimental results obtained by simulations with real images taken by various lighting and weather conditions show that the proposed method was quite successful, providing decision-making of noisiness with about 99%.

A Study on the Various Light Source Radiation Conditions and use of LED Illumination for Plant Factory (식물공장 각종광원의 방사조건과 LED조명의 활용에 관한 연구)

  • Yoon, Cheol-Gu;Choi, Hong-Kyoo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.10
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    • pp.14-22
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    • 2011
  • The artificial lights to be introduced for the plant factories is requiring the artificial light resources with minimizing the energy consumption to reduce the greenhouse gases which is a major cause of global warming, and maximizing the efficiency in photosynthesis effect light-wave range, in which the plants can be greatly grown and developed, and having the signal light-wave range for forming the light types. the best growing and developing environment for the plants has recently realized with utilizing the LED(Lighting Emitting Diode) lamps, as a environment-friendly green lamps, which can elevating the light efficiency with using only the specific light wave range. In this study, to provide the necessary lights for the full artificial light type of the plant factory, the following research/study and experiments has been conducting. experiments of the spectrum for each light sources, and LED, The intensity of illumination, Irradiance, Photosynthesis Photon Flux Density.

Implementation of Transceiver for Optical Wireless Communication System (광무선통신 시스템의 송수신기 구현)

  • Lee, Sun Yui;Kim, Jin Young
    • Journal of Satellite, Information and Communications
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    • v.8 no.1
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    • pp.71-76
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    • 2013
  • In this paper, a transceiver of VLC (Visible Light Communication) using LED white lighting has been implemented. The transmitted waveforms of LED and PD (Photo Diode) of the received signal are analyze to restore VLC data. Audio signal was successfully transmitted to demonstrate possibility and potential of optical wireless communication systems. Various modulation formats are considered to evaluate and compare performance in diverse channel conditions.

Corresponding Color Reproduction on CRT between Illuminated Environment viewing Conditions (관찰환경에 따른 소프트카피의 대응적 색재현)

  • 곽한봉;안성아;서봉우;이영호;안석출
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2001.06a
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    • pp.241-244
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    • 2001
  • A various color device became generalization. Therefore, request about expression of correct color is increased. Device independent color reproduction system acquires and reproduce color of object regardless characteristic of Input/Output device. Human visual system is partially adapted to the CRT monitor's white point and the ambient light. The visual experiments were performed on the effect of the ambient lighting under mixed chromatic adaptation. In this paper, It was found that human visual system is 40% to 60% adapted to CRT monitor's white point light and the rest to ambient light.

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Daylighting Performance Evaluation of Lightshelf Window System by Lightscape (Lightscape를 이용한 광선반 창호시스템의 채광성능평가)

  • Moon, Ki Hoon;Kim, Jeong Tai
    • KIEAE Journal
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    • v.4 no.4
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    • pp.45-52
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    • 2004
  • Simulation of daylighting by computer program is a method to avoid unnecessary efforts in manufacture of its testing models, to reduce its measuring tolerances and be able to provide variations of various weather conditions as well. Many simulation programs on daylighting have been released freely or commercialized for selling, however, a demonstration of their availability and validity as a tool for evaluating daylighting performance is required since each one has its own characteristics. The objectives of this study lie in suggesting an application method of evaluation tools and demonstration of limits and characteristics so as to more easily determine the daylightingperformance in the very initial stages of planning for an arbitrary office space in which windows with daylight access are built. We produced scale model of the general light inducing type side lighting with lightshelfand ceiling, and the luminance (at 78 measuring points) and illuminance (at 84 measuring points) were measured in a clear sky. And a comparison of the measured values and the calculated values from a computer simulation using the Lightscape program was performed.

Image-Based Fog Detection Algorithm Using a Neural Network (신경회로망 기반의 주야간 안개 감지 알고리즘)

  • Kang, Chung-Hun;Kim, Gyeong-Hwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.42 no.3
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    • pp.673-676
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    • 2017
  • In this paper, we propose a day and night fog detection algorithm that is not affected by lighting conditions. First, we present the definitions and the extraction methods of fog features in daytime and nighttime environments, respectively. We then propose the fog detection algorithm using a neural network from the fog features. A set of experiments has been conducted with images taken at various environments, and the average recall of the proposed algorithm is 97.5%.