• Title/Summary/Keyword: 어안 렌즈

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A Bump Mapping Method Using Camera Lens (카메라 렌즈를 이용한 범프 맵핑)

  • Koh, Wook
    • Journal of the Korea Computer Graphics Society
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    • v.3 no.1
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    • pp.9-15
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    • 1997
  • Most rendering research has concentrated on two sub-problems: modeling the reflection of light sources, and calculating the direct and indirect illumination from light sources and other surfaces. As Kolb wrote in [1], the camera and lens model is an important key component of a rendering system. In this paper we describe a bump-mapping method using camera lens. It allows another level of control in rendering. We developed an efficient framework to develop customized bump mapping lens and combine with other sequence of lens elements to create various effects as shown in Figure 2,3,4,5.

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Vision-based Mobile Robot Localization and Mapping using fisheye Lens (어안렌즈를 이용한 비전 기반의 이동 로봇 위치 추정 및 매핑)

  • Lee Jong-Shill;Min Hong-Ki;Hong Seung-Hong
    • Journal of the Institute of Convergence Signal Processing
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    • v.5 no.4
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    • pp.256-262
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    • 2004
  • A key component of an autonomous mobile robot is to localize itself and build a map of the environment simultaneously. In this paper, we propose a vision-based localization and mapping algorithm of mobile robot using fisheye lens. To acquire high-level features with scale invariance, a camera with fisheye lens facing toward to ceiling is attached to the robot. These features are used in mP building and localization. As a preprocessing, input image from fisheye lens is calibrated to remove radial distortion and then labeling and convex hull techniques are used to segment ceiling and wall region for the calibrated image. At the initial map building process, features we calculated for each segmented region and stored in map database. Features are continuously calculated for sequential input images and matched to the map. n some features are not matched, those features are added to the map. This map matching and updating process is continued until map building process is finished, Localization is used in map building process and searching the location of the robot on the map. The calculated features at the position of the robot are matched to the existing map to estimate the real position of the robot, and map building database is updated at the same time. By the proposed method, the elapsed time for map building is within 2 minutes for 50㎡ region, the positioning accuracy is ±13cm and the error about the positioning angle of the robot is ±3 degree for localization.

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Conversion of Fisheye Image to Perspective Image Using Nonlinear Scaling Function (비선형 스케일링 함수를 이용한 어안 영상의 원근 변환)

  • Kim, Tae-Woo;Cho, Tae-Kyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.1
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    • pp.117-121
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    • 2009
  • The fisheye image acquired with a fisheye camera has wider field of view than a general use camera. But large distortion of the object in the image requires conversion of the fisheye image to the perspective image because of user's difficult perception. The existing Ishii's method[1] has the problem that the object can has sire and geometrical distortion in the transformed image because it uses equidistance projection. This paper presented a conversion technique of the fisheye image to the perspective image using sealing function. In the experiments, it was shown that our method reduced size and geometrical distortion by applying the scaling function.

A Study on Detecting Moving Objects using Multiple Fisheye Cameras (다중 어안 카메라를 이용한 움직이는 물체 검출 연구)

  • Bae, Kwang-Hyuk;Suhr, Jae-Kyu;Park, Kang-Ryoung;Kim, Jai-Hie
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.4
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    • pp.32-40
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    • 2008
  • Since vision-based surveillance system uses a conventional camera which has a narrow field of view, it is difficult to apply it into the environment whose the ceiling is low and the monitoring area is wide. To overcome this problem, the method of increasing the number of camera causes the increase of the cost and the difficulties of camera set-up For these problems, we propose a new surveillance system based on multiple fisheye cameras which have 180 degree field of view. The proposed method handles occlusions using the homography relation between the multiple fisheye cameras. In the experiment, four fisheye cameras were set up within the area of $17{\times}14m$ at height of 2.5 m and five people wandered and crossed with one another within this area. The detection rates of the proposed system was 83.0% while that of a single camera was 46.1%.

Distortion Center Estimation using FOV Model and 2D Pattern (FOV 모델과 2D 패턴을 이용한 왜곡 중심 추정 기법)

  • Seo, Jeong-Goo;Kang, Euiseon
    • The Journal of the Korea Contents Association
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    • v.13 no.8
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    • pp.11-19
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    • 2013
  • This paper presents a simple method to estimate center of distortion and correct radial distortion from fish-eye lens. If the center of image is not locate that of lens in a straight line, the disadvantage of FOV model is low accurate because of correcting distortion without estimated centre of distortion. We propose a method accurately estimating Distortion center using FOV model and 2D pattern from wide angle lens. Our method determines the center of distortion in least error between straight lines and curves with FOV model. The results of experimental measurements on synthetic and real data are presented.

Correction of Fisheye Distortion and Perspective Distortion (어안렌즈왜곡 및 원근왜곡의 보정)

  • Song, Gwang-Yul;Yoon, Pal-Joo;Lee, Joon-Woong
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.10
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    • pp.22-29
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    • 2006
  • This paper considers the lens distortions such as a fisheye distortion and a perspective distortion. While a fisheye lens has a wide field-of-view, it causes a large distortion to the images. Regardless of a fisheye lens or a rectilinear lens, a lens generates perspective distortion in a vertical direction when the lens views in an upward direction or downward direction. These distortions deform images differently from human visual functions. Therefore, this paper presents a method to correct the distortions, and whereby, the research in this paper enlarges choices of images to image processing algorithm that may select the distorted images and the corrected images depending on applications. An infinite polynomial model is employed in the fisheye radial distortion correction, and the vertical perspective distortion correction is done by using a vanishing point. The methods introduced in this paper are implemented on the images captured by a rear-view camera installed on a vehicle and showed their robustness of the correction.

The Research for the Wide-Angle Lens Distortion Correction by Photogrammetry Techniques (사진측량 기법을 사용한 광각렌즈 왜곡보정에 관한 연구)

  • Kang, Jin-A;Park, Jae-Min;Kim, Byung-Guk
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.2
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    • pp.103-110
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    • 2008
  • General lens, widely using in Photogrammetry, has narrow view, and have to adjust "Image-Registration Method" after obtain images and it need cost; economic, period of time. Recent days, there is various study that use wide-angle lens, usually for robotics field, put to practical use in photogrammetry instead of general lens. In this studies, distortion tendency of wide-angle lens and utilize the correction techniques suitable to wide-angle lens by the existing photographic survey methods. After carrying out the calibration of the wide-angle lens, we calculated the correction parameters, and then developed the method that convert the original image-point to new image-point correcting distortion. For authorization the developed algorithm, we had inspection about shape and position; there are approximately 2D RMSE of 3 pixel, cx = 2, and cy = 3 different.

Design of an Achromatic Optical System Using a Symmetry Graphical Method (대칭 그래픽 방식을 이용한 광학계의 색수차 보정 설계)

  • Lim, Tae-Yeon;Ahn, Byoung-In;Jo, Sun-Hyoung;Kim, Jeongyun;Park, Sung-Chan
    • Korean Journal of Optics and Photonics
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    • v.29 no.1
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    • pp.13-18
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    • 2018
  • In this study, we present a symmetry graphical method to design an achromatic optical system composed of many lenses on an achromatic glass map. To take into account the lens spacing and the number of lenses, we use the relative ratio of paraxial ray height at each lens and the concept of an equivalent single lens. Converting an arbitrary optical system into various doublet systems, the most effective doublet is then selected to correct the color aberration, through material selection and the redistribution of the optical power. By designing a fisheye lens using this approach, an achromatic optical system is effectively obtained over the visible waveband.

An Experimental Comparison on Visualization Techniques of Long Menu-Lists (긴 메뉴항목 리스트의 시각화 기법 비교에 관한 실험적 연구)

  • Seo, Eun-Gyoung;Sung, Hye-Eun
    • Journal of the Korean Society for information Management
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    • v.24 no.2
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    • pp.71-87
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    • 2007
  • With the rapid change of the Web and E-transaction application, the search interface is providing more powerful search and visualization methods, while offering smoother integration of technology with task. Especially, visualization techniques for long menu-lists are applied in retrieval system with the goal of improving performance in user's ability to select one item from a long list. In order to review visualization techniques appropriate to the types of users and data set, this study compared the five visualization browsers such as the Tree-structured menu, the Table-of-contents menu, the Roll-over menu, the Click menu, and Fisheye menu. The result of general analyses shows that among the hierarchical methods, the experienced group prefers the Table-of-contents method menu, whereas the novice's group prefers the Tree-structure method menu. Among the linear methods, the two groups prefer the Roll-over menu. The Roll-over menu is most preferred among the five browsers by the two groups.

De-blurring Algorithm for Performance Improvement of Searching a Moving Vehicle on Fisheye CCTV Image (어안렌즈사용 CCTV이미지에서 차량 정보 수집의 성능개선을 위한 디블러링 알고리즘)

  • Lee, In-Jung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.4C
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    • pp.408-414
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    • 2010
  • When we are collecting traffic information on CCTV images, we have to install the detect zone in the image area during pan-tilt system is on duty. An automation of detect zone with pan-tilt system is not easy because of machine error. So the fisheye lens attached camera or convex mirror camera is needed for getting wide area images. In this situation some troubles are happened, that is a decreased system speed or image distortion. This distortion is caused by occlusion of angled ray as like trembled snapshot in digital camera. In this paper, we propose two methods of de-blurring to overcome distortion, the one is image segmentation by nonlinear diffusion equation and the other is deformation for some segmented area. As the results of doing de-blurring methods, the de-blurring image has 15 decibel increased PSNR and the detection rate of collecting traffic information is more than 5% increasing than in distorted images.