• 한국측량학회:학술대회논문집
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• 한국측량학회 2007년도 춘계학술발표회 논문집
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• pp.161-164
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• 2007

The paper studies in the wide-angle lens and distortion tendency and employs the correction techniques suitable to the fish-eye lens using the existing photographic survey methods. After carrying out the calibration of the the fish-eye lens, we calculated the correction parameters, and then developed the method that convert the original image-point to new image-point correcting distortion. The objectives of suggested calibration method in this paper are to calibrate the image of the the fish-eye lens used in the computer-vision and the control-instrumentation field widely. The proposed technique expects to improve the accuracy of the image of the fish-eye lens in the indoor tracking and monitoring field. Also the referenced cross point auto-extraction program is embodied for improving efficiency of the lens correction techniques. Consequently, this calibration method would be applied to the automated distorting correction method on not only the fish-eye lens also general lens.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2009년도 학술대회
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• pp.601-605
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• 2009

$180^{\circ}$ 이상의 영역을 획득하는 어안렌즈(fish-eye lens)는 최소의 카메라로 최대 시야각을 확보할 수 있는 장점으로 인해 차량 장착 시도가 늘고 있다. 운전자에게 현실감 있는 영상을 제공하고 센서로 이용하기 위해서는 캘리브레이션을 통해 방사왜곡(radial distortion)에 따른 기하학적인 왜곡 보정이 필요하다. 그런데 차량용 어안렌즈의 경우, 대각선 어안렌즈로 일반 원상 어안렌즈로 촬영한 둥근 화상의 바깥둘레에 내접하는 부분을 잘라낸 직사각형 영상과 같으며, 수직, 수평 화각에 따라 왜곡이 비대칭구조로 설계되었다. 본 논문에서는, 영상의 특징점(feature points)을 이용하여 차량용 어안렌즈에 적합한 카메라 모델 및 캘리브레이션 기법을 소개한다. 캘리브레이션한 결과, 제안한 방법은 화각이 다른 차량용 어안렌즈에도 적용 가능하다.

• 대한전자공학회논문지SP
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• 제42권5호
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• pp.79-84
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• 2005

일반적인 카메라의 시야는 사람에 비하여 매우 좁기 때문에 큰 물체를 한 화면으로 얻기 힘들며, 그 움직임도 넓게 감시하기에 어려움 점이 많다. 이에 본 논문에서는 어안 렌즈(Fish-Eye Lens)를 사용하여 넓은 시야의 영상을 획득하고 전방향 감시를 위한 투시(perspective) 영상과 파노라마(panorama) 영상을 복원하는 방법을 제시한다. 영상 변환 과정에서 어안 렌즈의 특성으로 인한 해상도 차이를 보완하기 위하여 여러 가지 영상 보간법을 적용하고 결과를 비교하였다. 그리고 ME(Moving Edge) 방법으로 움직임을 검출하여 다중 물체를 추적할 수 있도록 하였다.

• 전기학회논문지
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• 제62권9호
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• pp.1270-1275
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• 2013

A lot of research about camera calibration and lens distortion for wide-angle lens has been made. Especially, calibration for fish-eye lens which has 180 degree FOV(field of view) or above is more tricky, so existing research employed a huge calibration pattern or even 3D pattern. And it is important that calibration parameters (such as distortion coefficients) are suitably initialized to get accurate calibration results. It can be achieved by using manufacturer information or lease-square method for relatively narrow FOV(135, 150 degree) lens. In this paper, without any previous manufacturer information, camera calibration and barrel undistortion for fish-eye lens with over 180 degree FOV are achieved by only using one calibration pattern image. We applied QR decomposition for initialization and Regularization for optimization. With the result of experiment, we verified that our algorithm can achieve camera calibration and image undistortion successfully.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.299-301
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• 1996

Since a standard lens has small sight angle, a fish-eye lens can be used in order to obtain wide sight angle for the robot vision system. In spite of the advantage, the image through the lens has variable resolution; the central information of the lens is of high resolution, but the peripheral information is of low resolution. Owing to this difference of resolution, the variable resolution image should be transformed to a uniform resolution image in order to determine the positions of the objects in the image. In this work, the correction method for the distorted image is presented and the performance is analyzed. Furthermore, the camera with a fish eye lens can be used to determine the real world coordinates. The performance is shown through experiments.

• 한국컴퓨터정보학회논문지
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• 제13권4호
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• pp.97-103
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• 2008

이 논문은 응급상황을 인식하기 위하여 어안렌즈를 통해 획득된 영상을 이용하여 기절 동작을 인식하는 방법을 제안한다. 거실의 천장 중앙에 위치한 어안렌즈(fish-eye lens)를 장착한 카메라로부터 영상을 입력 받은 뒤, 가우시안 혼합 모델 기반의 적응적 배경 모델링 방법을 이용하여 전경 픽셀을 추출한다. 그리고 연결되어 있는 전경픽셀 영역들의 외곽점들을 추적하여 타원으로 매핑한다. 이 타원을 추적하면서 어안 렌즈 영상을 투시 영상으로 변환한 다음 타원의 크기 변화, 위치 변화, 이동 속도정보를 추출하여 이동과 정지 및 움직임이 기절동작과 유사한지를 판단한다. 실험 결과 어안 렌즈 영상을 그대로 사용하는 것보다 투시 영상으로 변환하여 타원의 크기변화, 위치변화, 이동속도 정보를 추출하는 방법이 보다 높은 인식률을 보였다.

• 한국어병학회지
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• 제16권2호
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• pp.75-80
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• 2003

Red scabream, Pagrus major , is a valuable aquaculture species in Korea , but spontaneous eye abnormality occurred in cultured individuals . The incidence of eye abnormality was 4% in the group of cultured red scebream. The abnormality was characterized by unilateral and bilateral exophthalmos, opacity and lens pathology. Lense prolapse was found in two cases. Lenses in diseased fishes was considerably small in diameter and eyes were deformed as a whole. In the group of induced hybrid red scabream Pagrus major (♀) x black seabrearn Acanthopagrus schlegeli (♂), the incidence of eye abnormality wa~ the same 4%, but only opacity was registered. Opacity was also found in two of sixteen examined Wild-caught red seabrcam. Histopathological changes of lenses in cultured red seabreem included vecuolated cytoplasm of lens fibers, necrosis of fibers in central part of lens, folding and increase in thickness of lens capsule, and epithelial proliferation beneath the anterior lens capsule. In affected eyes no parasites or gas bubbles were found.

• 한국측량학회지
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• 제27권3호
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• pp.323-330
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• 2009

최근 도시시설물의 안전과 범죄 모니터링에 대한수요가 증가하고 있으나, 사용되는 산업장비용 CCTV의 경우 고가가 대부분이다. 본 연구에서는 초 광각 렌즈인 어안렌즈와 사진측량 알고리즘을 이용하여 단일 카메라의 시야각을 증대시켜 모니터링의 효율성을 극대화 시키고자 한다. 어안렌즈를 이용한 모니터링을 위해 우선 실험실 내에서 왜곡계수 산출 실험을 실시하였는데 이는 일정 간격의 고정된 종이 타겟을 여러 방향에서 촬영한 후, 격자점을 이용하여 왜곡 계수를 추출하였다. 또한 추출된 왜곡보정 계수를 보정 및 모니터링 프로그램에 삽입하여 실시간 보정된 영상을 획득할 수 있다. 또한 보정된 영상에 대한 검증을 위해, 타겟을 스캐닝하여 왜곡 보정된 영상과 비교한 결과 RMSE가 3.2pixel로 나타났다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.663-668
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• 2003

This paper presents a new observation system which is useful to observe the scene of the remote controlled robot vision. This system is composed of a motionless camera and head motion detector with a motion sensor. The motionless camera has a fish eye lens and is for observing a hemisphere space. The head motion detector has a motion sensor is for defining an arbitrary subspace of the hemisphere space from fish eye lens. Thus processing the angular information from the motion sensor appropriately, the direction of face is estimated. However, since the fisheye image is distorted, it is unclear image. The partial domain of a fish eye image is selected by head motion, and this is converted to perspective image. However, since this conversion enlarges the original image spatially and is based on discrete data, crevice is generated in the converted image. To solve this problem, interpolation based on an intensity of the image is performed for the crevice in the converted image (space problem). This paper provides the experimental results of the proposed observation system with the head motion detector and perspective image conversion using the proposed conversion and interpolation methods, and the adequacy and improving point of the proposed techniques are discussed.

• 한국조경학회지
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• 제33권4호
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• pp.11-21
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• 2005

The purpose of this study was to analyze and evaluate landscape characteristics by classification of landscapes in Chuncheon. A system was developed to convert images taken with a fish-eye lens to panoramic pictures. Landscape characteristics were analyzed by appearance rate and area distribution rate of landscape elements on panorama picture. Landscape characteristics were analyzed according to the number of times landscape elements appeared and the amount of area that each element occupied in the panoramic picture. Each panoramic picture was classified into five types based on these landscape element factors. Landscape evaluation was carried out using dynamic images converted from picture by fish-eye lens. The results of this study can be summarized as follows. The urban landscape can be characterized by four essential factors: interconnectedness, nature, urban centrality and landscape scale. Five types of landscapes were determined: detached residential building landscape (type 1), street landscape with various elements (type 2), street landscape in the center of a city (type 3), landscape of housing complex (type 4), and landscape of green space (type 5). Type 5 had the highest degree of landscape satisfaction and the landscape satisfaction increased with the number of appearances of natural elements. The amount of peen space had a high relation with a landscape satisfaction.