• Journal of Digital Contents Society
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• v.19 no.1
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• pp.165-171
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• 2018

Shadow is a physical phenomenon observed in natural scenes and has a negative effect on various image processing systems such as intelligent video surveillance, traffic surveillance and aerial imagery analysis. Therefore, shadow detection should be considered as a preprocessing process in all areas of computer vision. In this paper, we define and analyze various feature elements for shadow detection in a single natural image that does not require a reference image. The shadow elements describe the intensity, chromaticity, illuminant-invariant, color invariance, and entropy image, which indicate the uncertainty of the information. The results show that the chromaticity and illuminant-invariant images are effective for shadow detection. In the future, we will define a fusion map of various shadow feature elements, and continue to study shadow detection that can adapt to various lighting levels, and shadow removal using chromaticity and illuminance invariant images.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.759-762
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• 2001

주행차량의 영상으로부터 개별차량이 포함하는 고유정보를 추출하는 과정은 선택된 프레임에 포함된 차량의 위치 및 상태에 의존적이다. 고정된 카메라에 의해 설정된 영상내의 기준을 불규칙적으로 진행하는 개별차량에 동일하게 적용하는 것은 특징요소의 검출과 인식에서 결과의 신뢰성에 영향을 준다. 프레임 선택과정에서는 도로상의 그림자가 차량검출을 어렵게 하는 요소이다. 본 논문에서는 그림자의 영향을 받지 않고 영상내 설정된 범위에 차량이 위치한 프레임을 선택하는 방법과 불규칙적으로 진행하는 개별적인 차량의 기준을 설정하는 방법을 제시하였고, 차량이 포함하는 패턴을 이용하여 특징요소의 위치를 인식하는 방법에 대해 실험하였다.

• Journal of Digital Contents Society
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• v.19 no.9
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• pp.1787-1793
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• 2018

Shadow is a common phenomenon observed in natural scenes, but it has a negative influence on image analysis such as object recognition, feature detection and scene analysis. Therefore, the process of detecting and removing shadows included in digital images must be considered as a pre-processing process of image analysis. In this paper, the existing methods for acquiring 1D invariant images, one of the feature elements for detecting and removing shadows contained in a single natural image, are described, and a method for obtaining 1D invariant images based on linear regression has been proposed. The proposed method calculates the log of the band-ratio between each channel of the RGB color image, and obtains the grayscale image line by linear regression. The final 1D invariant images were obtained by projecting the log image of the band-ratio onto the estimated grayscale image line. Experimental results show that the proposed method has lower computational complexity than the existing projection method using entropy minimization, and shadow detection and removal based on 1D invariant images are performed effectively.

• Journal of The Korean Association For Science Education
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• v.41 no.5
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• pp.371-390
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• 2021

The purpose of this study is to develop a neuropsychological model for the spatial ability factor and to divide the brain active area involved in the light & shadow problem solving process into the domain-general ability and the domain-specific ability based on the neuropsychological model. Twenty-four male college students participated in the study to measure the synchronized eye movement and electroencephalograms (EEG) while they performed the spatial ability test and the light & shadow tasks. Neuropsychological model for the spatial ability factor and light & shadow problem solving process was developed by integrating the measurements of the participants' eye movements, brain activity areas, and the interview findings regarding their thoughts and strategies. The results of this study are as follows; first, the spatial visualization and mental rotation factors mainly required activation of the parietal lobe, and the spatial orientation factor required activation of the frontal lobe. Second, in the light & shadow problem solving process, participants use both their spatial ability as a domain-general thought, and the application of scientific principles as a domain-specific thought. The brain activity patterns resulting from a participants' inferring the shadow by parallel light source and inferring the shadow when the direction of the light changed were similar to the neuropsychological model for the spatial visualization factor. The brain activity pattern from inferring an object from its shadow by light from multiple directions was similar to the neuropsychological model for the spatial orientation factor. The brain activity pattern from inferring a shadow with a point source of light was similar to the neuropsychological model for the spatial visualization factor. In addition, when solving the light & shadow tasks, the brain's middle temporal gyrus, precentral gyrus, inferior frontal gyrus, middle frontal gyrus were additionally activated, which are responsible for deductive reasoning, working memory, and planning for action.

• Journal of Broadcast Engineering
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• v.26 no.4
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• pp.419-428
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• 2021

Shadow removal plays a key role for the pre-processing of image processing techniques such as object tracking and detection. With the advances of image recognition based on deep convolution neural networks, researches for shadow removal have been actively conducted. In this paper, we propose a novel method for shadow removal, which utilizes self attention distillation to extract semantic features. The proposed method gradually refines results of shadow detection, which are extracted from each layer of the proposed network, via top-down distillation. Specifically, the training procedure can be efficiently performed by learning the contextual information for shadow removal without shadow masks. Experimental results on various datasets show the effectiveness of the proposed method for shadow removal under real world environments.

• Journal of the Korea Computer Graphics Society
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• v.18 no.1
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• pp.1-9
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• 2012

Video-based modeling / rendering developed to produce photo-realistic video contents have been one of the important research topics in computer graphics and computer visions. To smoothly combine original input video clips and 3D graphic models, geometrical information of light sources and cameras used to capture a scene in the real world is essentially required. In this paper, we present a simple technique to estimate the position and orientation of an optimal light source from the topology of objects and the silhouettes of shadows appeared in the original video clips. The technique supports functions to generate well matched shadows as well as to render the inserted models by applying the estimated light sources. Shadows are known as an important visual cue that empirically indicates the relative location of objects in the 3D space. Thus our method can enhance realism in the final composed videos through the proposed shadow generation and rendering algorithms in real-time.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.105-110
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• 2001

차량이 증가함에 따라서 첨단 교통 시스템(intelligent Transportation System: ITS)은 교통의 효율성, 신뢰성, 안정성 향상에 중점을 두게되었다. 첨단 교통 시스템의 일부분인 운전자 도움 시스템(Advanced Drivers Assistance System)은 운전을 하고 있는 상황에서 도움을 주기 위한 체계이고, 전방의 장애물 검지는 운전자 도움 시스템에서 전방의 상황을 운전자에게 알려주기 위한 중요한 요소이다. 본 논문에서는 HSV 컬러모델을 이용하여 연속된 컬러 영상으로부터 도로상의 차선과 방향 표시자에 구애받지 않고 전방의 차량을 검출하는 방법을 제안한다. HSV 컬러 모텔에서 차량을 검출하기 위해서는 태도(Saturation)와 명도(Value)성분의 관계를 이용하여 차량 영역을 구하고, HSV성분과 위치 특징을 이용하여 이전 프레임의 차량인지 검증한다. 도로 영상에서 차량이 있는 경우 차량의 아래 부분에 그림자 영역이 존재한다는 점을 이용한다. 제안된 방식의 효과를 검증하기 위해 노트북 PC와 PC용 CCD 카메라로 도로에서의 영상을 촬영하고 차량검출알고리즘을 적용한 처리 시간, 정확도, 차량검지 등의 결과를 보인다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.267-270
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• 2016

차량 인식 기술은 지능형 자율주행 차량 및 첨단 운전자 보조 시스템 (ADAS: Advanced Driver Assistance System)의 개발에 있어서 핵심 요소 기술이다. 영상 기반의 차량 검출 알고리즘은 일반적으로 가설 생성 (HG: Hypothesis Generation) 단계와 가설 검증 (HV: Hypothesis Verification) 단계로 구성된다. 가설 검증 단계는 관심 영역 (ROI: Region of Interest) 내에 차량이 존재할 가능성이 있는 후보 영역을 만드는 단계로서 전체 알고리즘의 복잡도와 성능에 영향을 미친다. 본 논문에서는 관심 영역 내에 존재하는 그림자와 차량으로 인한 에지를 검출하고 두 특징 정보를 결합한 가설 생성 방법을 제안하고 차량 후방 영상을 이용하여 사각지대를 감시하는 시스템에 제안 방법을 적용하는 실험을 수행하였다. 실험 결과로 제안 방법이 차량 후보 영역의 존재 여부와 위치 정보를 판단하기에 적합하며 이를 통해 차량 검출 알고리즘의 계산 복잡도를 개선하면서도 다음 단계인 가설 검증 시 검출 성능을 향상시킬 수 있음을 확인하였다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.13-18
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• 2002

Foreign construction requires the globalization of management structure and role execution as a global manager. Therefore, this paper prospects the light and shadow of Korea construction business with the consideration about the foreign construction market and Korea's foreign construction. This paper interprets meaning about the foreign construction and analyzes the distinction, strategy, and competitive factor of foreign construction business. On the basis of interpretation and analysis, this paper suggests the innovative change of the domestic construction business manager and management system.

• Cartoon and Animation Studies
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• s.44
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• pp.263-284
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• 2016

The transformation of plots using the archetypical narratives is not just a repetition of the past story, but finding a new suitable meaning for present time and society. Due to this, the story can be variated depending on what the transformation has the main point for. Disney's animation overcomes the narrative feature of the past classic fairy tale that worked only for particular age and people, and recognized as a contemporary story that can give impression to more various people. This study use Vladimir Propp's Morphology of the Folktale, Carl Gustav Jung's complexes and shadow theory to examine how this animation is modernly recreated by transforming the archetypical narrative. As a result, we can find characteristics of structure and function for contemporary story, and those also work with characters in the recreated animation. Through this study we discovered that Disney's animation is a transfiguration of archetypical narrative through the exhaustive analysis, and this could be the helpful research for the future creation of animation which uses the archetypical narratives.