• 전자공학회논문지B
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• 제33B권5호
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• pp.118-126
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• 1996

In object analysis by image processing, finding lines plays a universal role. And these lines can be easily found by detecting ridges and valleys in digital gray scale images. In this paper, a new method of detecting ridges and valleys by using local min/max operations was presented. This method detects ridges and valleys of desired width by using erosion and dilation properties of local min/max operations, and requires no information of ridge or valley direction. Therefore the method is efficient and computationally simple in comparision with the conventional analytical method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.730-734
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• 2003

A beamforming method is a kind of spatial filter that focus the amy's signal capturing abilities in a desired direction. In this paper, we detect the location of a source under reflective condition using the multi-dimensional MUSIC algorithm then, we can iud the image source locations from the experimental geometry, and we reconstruct the partial fields for direct wave and reflected wave by using Adaptive nulling algorithm. Numerical simulations are performed to verify its performance under various conditions.

• 전자공학회논문지
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• 제53권5호
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• pp.123-131
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• 2016

저조도 환경에서 근적외선은 사람 눈에 보이지 않는 추가적인 정보를 제공하여 물체를 보다 분명하게 구별하고 인식하도록 도움을 준다. 컬러 영상과 근적외선 영상을 동시에 획득하기 위해서 다중 분광 필터 배열을 사용하였다. 그러나 렌즈의 굴절률은 빛의 파장 길이에 따라 다르기 때문에 초점면에 상이 다르게 맺히게 된다. 그 결과 색수차 문제가 발생하고 영상은 흐려지게 되며 영상의 해상도가 떨어지게 된다. 본 논문에서는 이러한 색수차 문제를 고려한 영상 복원 알고리즘을 제안하고자 한다. 다중 분광 필터 배열 영상에 컷오프 주파수가 추정된 저주파 통과 필터를 적용하여 기반 영상을 추정하도록 하였다. 이 영상을 이용하여 다중 분광 영상의 색수차 문제가 해결된 영상을 추정하도록 하였다. 영상 획득 과정에서, 색수차 문제와 기반 영상 형성 과정을 모델링하였다. 이러한 모델을 바탕으로, 기반 영상과 다중 분광 영상 간의 고주파 성분 차이에 대한 최소 자승법을 풀어서 다중 분광 영상을 획득하도록 하였다. 실험 결과는 제안하는 알고리즘이 색수차 문제가 최소화된 고화질의 다중 분광 영상을 추정한 것을 보여준다.

• 한국정보과학회논문지:데이타베이스
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• 제29권1호
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• pp.27-33
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• 2002

트리플 이미지 색인 기법에는 두 가지 문제점이 있는 데 그 하나는 개념기반 이미지 검색을 지원하지 않는다는 것이고 다른 하나는 이접 레이블링(labeling)이 허용되지 않는다는 점이다. 이 문제점들을 해결하기 위해서 본 논문에서는 불확정적 퍼지 트리플(I-퍼지 트리플)이라는 새로운 이미지 색인 자료 형을 제안한다. I-퍼지 트리플에 의한 이미지 색인 방식에서는 이접 레이블링을 허용하기 때문에, 이미지 내 객체들이 꼭 확정적으로 인식될 필요가 없으며, 또 확정적으로 인식되지 않는 이미지들에 대해서도 개념 기반 이미지 정합이 가능하다. 본 논문에서 제안하는 이접 레이블링은 확장된 폐 세계 가정에 기반을 두고 있으며, 기념 기반 이미지 검색은 퍼지 술어에 의한 정합에 근거를 두고 있다. 본 논문에서는 또한 이접 레이블링에 의해 불확정적으로 색인된 이미지 데이터베이스로부터 원하는 답을 $\alpha$$\in$[0,1]확정도로 구해내는 개념기반 질의 평가 방식도 제안한다.

• 보존과학회지
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• 제37권4호
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• pp.312-321
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• 2021

Underwater archaeology relies heavily on photography and video image recording during surveillances and excavations like ordinary archaeological studies on land. All underwater images suffer poor image quality and distortions due to poor visibility, low contrast and blur, caused by differences in refractive indices of water and air, properties of selected lenses and shapes of viewports. In the Yellow Sea (between mainland China and the Korean peninsula), the visibility underwater is far less than 1 m, typically in the range of 30 cm to 50 cm, on even a clear day, due to very high turbidity. For photographing 1 m x 1 m grids underwater, a very wide view angle (180°) fisheye lens with an 8 mm focal length is intentionally used despite unwanted severe barrel-shaped image distortion, even with a dome port camera housing. It is very difficult to map wide underwater archaeological excavation sites by combining severely distorted images. Development of practical compensation methods for distorted underwater images acquired through the fisheye lens is strongly desired. In this study, the source of image distortion in underwater photography is investigated. We have identified the source of image distortion as the mismatching, in optical axis and focal points, between dome port housing and fisheye lens. A practical image distortion compensation method, using customized image processing software, was explored and verified using archived underwater excavation images for effectiveness in underwater archaeological applications. To minimize unusable area due to severe distortion after distortion compensation, practical underwater photography guidelines are suggested.

• 한국통신학회논문지
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• 제18권6호
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• pp.895-906
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• 1993

본 논문에서는 영상의 대역분할 부호화를 위한 다중비트율 트리구조 벡터양자화를 제안하였다. 영상의 대역분할은 원영상을 특정 대역과 방향성을 갖는 대역성분들로 분리하므로, 대역분할을 거친 각 대역성분을 학습영상으로 사용하여 다중비트율 트리구조 벡터양자화기를 설계하였다. 대역분할을 거친 각 대역성분에 대한 최적비트할당은 원하는 비트율과 왜곡을 갖는 다중 비트율 트리구조 벡터양자화기의 전정서브트리를 선택하는 문제로 귀착된다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제11권3호
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• pp.211-216
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• 2011

The detection of defective parts in a factory is usually performed by the human eye. Therefore, heavy manpower is in demand for minor enterprises. An image processing system is desired to solve this drawback. However, due to the variety of the products characteristics, an general algorithm is needed that can adapt to these characteristics. Therefore, in this paper, the key pad parts' characteristics which need to be dealt with are analyzed in order to embody the image processing algorithm that is suggested. The experimental results show the probability of detecting a defective part is 95% with a detection time of 0.203 seconds, on the average.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2007년도 춘계학술대회 논문집
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• pp.71-72
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• 2007

In this study and design, I explore the visual communication design process related to wayfinding in Wonkwang University Hospital in Iksan City. The purpose for designing an integrated is to graphically communicate the complex information. I have designed a graphic information system combining graphic elements such as typography, color, image and text layout, and graphic image to present interpretive and communicative processes. As a result of designing, the wayfinding is s term used to describe the program of applying environmental graphics and or architectural sign systems. In other words, wayfinding is the art of helping people find their way by utilizing visual communications such as signs, directories, landmarks, edges, paths and so on. Wayfinding can also be explained as the ability to know where one is in space and how to find one's way through space. Wayfinding design then becomes a systematic arrangement of the variables that allows patients and visitors to successfully find their desired destinations, especially in a hospital.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제18권3호
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• pp.225-244
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• 2014

In this work, we discuss segmentation algorithms based on the level set method that incorporates shape prior knowledge. Fundamental segmentation models fail to segment desirable objects from a background when the objects are occluded by others or missing parts of their whole. To overcome these difficulties, we incorporate shape prior knowledge into a new segmentation energy that, uses global and local image information to construct the energy functional. This method improves upon other methods found in the literature and segments images with intensity inhomogeneity, even when images have missing or misleading information due to occlusions, noise, or low-contrast. We consider the case when the shape prior is placed exactly at the locations of the desired objects and the case when the shape prior is placed at arbitrary locations. We test our methods on various images and compare them to other existing methods. Experimental results show that our methods are not only accurate and computationally efficient, but faster than existing methods as well.

• 대한전기학회논문지
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• 제43권6호
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• pp.1010-1019
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• 1994

It is shown that there exists a nonlinear mapping which transforms image features and their changes to the desired camera motion without measuring of the relative distance between the camera and the object. This nonlinear mapping can eliminate several difficulties occurring in computing the inverse of the feature Jacobian as in the usual feature-based visual feedback control methods. Instead of analytically deriving the closed form of this mapping, a Fuzzy Membership Function-based Neural Network (FMFNN) incorporating a Fuzzy-Neural Interpolating Network is used to approximate the nonlinear mapping. Several FMFNN's are trained to be capable of tracking a moving object in the whole workspace along the line of sight. For an effective implementation of the proposed FMF network, an image feature selection process is investigated. Finally, several numerical examples are presented to show the validity of the proposed visual servoing method.