• International Journal of CAD/CAM
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• 제12권1호
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• pp.38-47
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• 2012

The paper proposes a method for generating a sequence of images with smooth transition of illumination from two input images with different lighting conditions. Our relighting approach is image-based, such as the light field rendering. We store the luminances (pixel RGB values) into "lighting functions" consisting of a couple of parameters related to normal vectors. Images with different light positions are rendered by interpolating the luminances retrieved from the lighting functions. The proposed method is a promising technique for many applications requiring a scene with variety of lighting effects, such as movies, TV games, and so on.

• 한국컴퓨터그래픽스학회논문지
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• 제20권1호
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• pp.13-19
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• 2014

본 논문에서는 현실감 있는 렌더링을 위하여 최근 널리 사용되고 있는 영상 기반 조명(image-based lighting)과정을 실시간으로 처리하기위한 기술을 다룬다. 기존의 영상을 광원으로 사용하는 실시간 렌더링 기법에서는 주로 난반사(diffuse reflection)와 거울 면 정반사(mirror-like specular reflection)을 다루는 반면, 본 논문에서는 기존에 컴퓨터 그래픽스 분야에서 널리 사용하던 퐁 반사 모델(Phong reflection model)을 실시간으로 렌더링 하기 위한 방법을 제안한다. 특히 새로운 방법론 보다는 기존의 방법들을 확장하여 게임이나 실시간 미리보기 등의 응용에서 전통적인 방법으로 제작된 표면 속성을 가지는 기하객체를 보다 사실적으로 렌더링하기 위한 실용적인 방법을 제안한다. 난반사의 경우에는 기존의 방법과 유사하게 전처리 과정에서 원본 광원 영상으로부터 난반사를 실시간으로 계산하기 위한 영상을 생성하는 방법을 사용한다. 정반사의 경우에도 유사하게 전처리 과정에서 광택도(shininess)에 따른 반사 맵을 미리 생성하고 이를 물체의 광택도(shininess)에 따라서 보간하는 방법을 사용한다. 이와 같은 방법으로 실시간에 비교적 매우 적은 양의 계산과 적은 텍스처 참조를 통하여 영상 기반 조명을 근사할 수 있다.

• 한국의상디자인학회지
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• 제17권3호
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• pp.1-11
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• 2015

This study comparatively analyzed the images and preference of lighting space using the emotion-based technique in order to effectively use it in clothing shops and fashion marketing. In terms of color temperature for light sources, 2,800K of lamp color, 6,500K of daylight color and 4,200K of white color were used. For the assessment, sensory evaluation technique was used. Then, the study found the followings: In terms of the image of lighting space by light source, different images were observed by light source with significant difference by the evaluation category. For factor analysis by the evaluation category, 7 factors were extracted. Among them, evaluation on lighting space was influenced by the following three images: modern space, elegant space and classical space. In particular, the modern space comprised of the following adjectives had the biggest effect on the assessment of the image of lighting space ('refreshing,' 'transparent,' 'bluish,' 'bright' and 'non-classical') (primary evaluation 30.13%). According to assessment on the preference of lighting space, the respondents' most favorite lighting space was 4,200K while their least favorable one was 6,500K in terms of color temperature. In terms of preference by the image of lighting space, they didn't like 'non-elegant' and 'non-beige' images even though they had the images of modern space. Therefore, it was confirmed that beige and elegant space images have an effect on the preference of lighting space.

• 한국인터넷방송통신학회논문지
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• 제14권3호
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• pp.147-153
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• 2014

본 논문에서는 안드로이드 플랫폼 기반의 스마트 감성조명 제어 시스템을 제안한다. 제안된 스마트 감성조명제어 시스템은 안드로이드 플랫폼, 감성조명 장치, 확장 디바이스와 지그비 모듈을 사용하였다. 안드로이드 플랫폼 기반의 스마트 감성조명 제어 시스템은 조도센서를 이용하여 자동제어와 수동제어 선택이 가능하며, 원하는 조명만을 선택하여 부분적인 제어도 가능하게 설계하였다. 제안된 스마트 감성조명 제어 시스템의 실험 결과 필요로 하는 부분의 조명기기 제어와 색온도 가변에 의한 제어가 가능하였고, 감성어휘에 의한 가변점등으로 효율적으로 기존 감성조명 제어 시스템보다 전력 소비를 감소시켰다. 그리고 상황에 적합한 색상과 밝기를 제어하여 사무실에서 행위를 함에 있어 집중력과 업무능력 향상에도 효과적인 제어가 가능하였다.

• 한국멀티미디어학회논문지
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• 제20권9호
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• pp.1481-1490
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• 2017

This paper presents an image quality enhancement algorithm for dark image acquired under poor lighting condition. Various retinex algorithms which are human perception-based image processing methods were proposed to solve this problem. Although MSR(Multi-Scale Retinex) among these algorithm works well under most lighting condition, it shows color degradation because their separate nonlinear processing of RGB color channels. To compensate for the loss of the color, MSRCR(Multi-Scale Retinex with Color Restoration) was proposed. However, it requires high computational load and has additional parameters that need to be adjusted according to input image. In order to overcome this problem, a new retinex algorithm based on MSR is proposed in this paper. The proposed method consists of V channel MSR, saturation correction, and separate contrast enhancement process. Experimental results show that the subjective and objective image quality of the proposed method better than those of the conventional methods.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.955-956
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• 2008

This paper presents a new method for illumination normalization in eye detection. Based on the retinex image formation model, we employ the discrete wavelet transform to remove the lighting effect in face image data. The final result based on the proposed method shows the better performance in detecting eyes compared with previous work.

• Journal of Multimedia Information System
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• 제6권4호
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• pp.329-332
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• 2019

Recently, smart lighting systems are the combination between sensors and lights. These systems turn on/off and adjust the brightness of lights based on the motion of object and the brightness of environment. These systems are often applied in places such as buildings, rooms, garages and parking lot. However, these lighting systems are controlled by lighting sensors, motion sensors based on illumination environment and motion detection. In this paper, we propose an automatic lighting control system using one single camera for buildings, rooms and garages. The proposed system is one integration the results of digital image processing as motion detection, hand gesture detection to control and dim the lighting system. The experimental results showed that the proposed system work very well and could consider to apply for automatic lighting spaces.

• ETRI Journal
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• 제45권6호
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• pp.1022-1034
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• 2023

In this study, the impact of varying lighting conditions on recognition and decision-making was considered. The luminosity approach was presented to increase gesture recognition performance under varied lighting. An efficient framework was proposed for sensor-based sign language gesture identification, including picture acquisition, preparing data, obtaining features, and recognition. The depth images were collected using multiple Microsoft Kinect devices, and data were acquired by varying resolutions to demonstrate the idea. A case study was designed to attain acceptable accuracy in gesture recognition under variant lighting. Using American Sign Language (ASL), the dataset was created and analyzed under various lighting conditions. In ASL-based images, significant feature points were selected using the scale-invariant feature transformation (SIFT). Finally, an artificial neural network (ANN) classified hand gestures using specified characteristics for validation. The suggested method was successful across a variety of illumination conditions and different image sizes. The total effectiveness of NN architecture was shown by the 97.6% recognition accuracy rate of 26 alphabets dataset with just a 2.4% error rate.

• 대한기계학회논문집A
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• 제21권1호
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• pp.1-11
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• 1997

Austomated visual inspection(AVI) capability has become an important key component in the automated manufacturing system. In such a visual inspection system an intensity(or color) image of a scene is quickly affected by optical property of objects, condition and roughness of surface, lens and filters, image sensor property and lighting system. In particular, the lighting system disign is the most important factor, since it affects overall performance of the visual system. For fast and cheap automated visual inspection system it is important to obtain the good image quality which results from careful attention to the design of the lighting system. In this paper, the lighting subsystem of AVI system is analysed for the inspection of printed circuit board(PCB) patterns. The spectral reflectance of materials, which are composed of PCB, is measured for choosing the light source. The reflection property is theoretically obtained by a reflection model and also obtained by experiments which measure intensity with varying the viewing direction of image sensor and the lighting direction of illuminator. The illumination uniformity of a ring-type illuminator. The lighting system is designed based upon the experimental results and theoretial analysis.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권5호
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• pp.235-240
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• 2000

A low cost lighting system for line-scan cameras has been developed with 3-phase power. When exposure time of line-scan camera is shorter than fluctuation period of illumination, the average gray value of each acquired 1-D image varies. Detecting defects on the objects's surface under such illuminating environment is very difficult. The proposed lighting system is composed of low-cost fluorescent lights based on 3-phase power. The specially designed lighting pack and the properly selected lighting position enable to get the rippleless lighting. The principle of the proposed lighting system has been explained analytically. The lighting system has been tested for fabric inspection with line-scan camera and it's efficacy has been proved.