DOI QR코드

DOI QR Code

A Distortion Correction Method of Wide-Angle Camera Images through the Estimation and Validation of a Camera Model

카메라 모델의 추정과 검증을 통한 광각 카메라 영상의 왜곡 보정 방법

  • 김경임 (전남대학교 디지털컨버전스협동과정) ;
  • 한순희 (전남대학교 문화콘텐츠학부) ;
  • 박정선 (전남대학교 문화콘텐츠학부)
  • Received : 2013.10.05
  • Accepted : 2013.12.16
  • Published : 2013.12.31

Abstract

In order to solve the problem of severely distorted images from a wide-angle camera, we propose a calibration method which corrects a radial distortion in wide-angle images by estimation and validation of camera model. First, we estimate a camera model consisting of intrinsic and extrinsic parameters from calibration patterns, where intrinsic parameters are the focal length, the principal point and so on, and extrinsic parameters are the relative position and orientation of calibration pattern from a camera. Next we validate the estimated camera model by re-extracting corner points by inversing the model to images. Finally we correct the distortion of the image using the validated camera model. We confirm that the proposed method can correct the distortion more than 80% by the calibration experiments using the lattice shaped pattern images captured from a general web camera and a wide-angle camera.

본 논문에서는 광각 카메라로 촬영한 영상에서 생기는 영상의 왜곡 문제를 해결하기 위하여, 카메라 모델의 추정과 검증을 통하여 광각 카메라 영상에서의 방사형 왜곡을 보정하는 방법을 제안한다. 먼저, 교정 패턴으로부터 렌즈의 초점 거리와 주점의 위치 등으로 구성된 내부 파라미터와 회전과 위치 정보로 구성된 외부 파라미터를 찾음으로써 카메라의 왜곡 모델을 추정한다. 다음으로, 추정된 카메라 모델로부터 역으로 코너점을 다시 추출하여 검증하고, 마지막으로, 검증된 카메라 모델을 이용하여 영상의 왜곡을 보정한다. 일반 웹 카메라와 광각 카메라로부터 격자 모양의 교정 패턴을 촬영한 영상을 이용하여 방사형 왜곡을 보정하는 실험을 수행한 결과, 제안된 방법이 80% 이상의 개선 성능을 보임을 확인하였다.

Keywords

References

  1. Gary Rost Bradski and Adrain Kaehler, "Learning OpenCV : Computer Vision with the OpenCV Library", O'Reilly Media, 2008.
  2. R. Swaminathan and S.K. Nayar, "Nonmetric Calibration of Wide-angle Lenses and Polycameras", IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 22, No. 10, pp. 1172-1178, 2000. https://doi.org/10.1109/34.879797
  3. J.-S. Lee, S.-C.. Hong, Min-Goo Kang, and S.-I. Sonh, "Design of 2m High Resolution Wideangle Lenz for Smart NUX", in Proc. of the Spring conference of the Korea Institute of Electronic Communication Sciences, Vol. 6, No. 1, pp. 71-74, 2012.
  4. Jae-Gon Lee, Min-Goo Kang, Won-Kyu Kim, and Kyung-Taek Lee, "Design of Highresolution Wide-angle Lenz Module, and Image Distortion Compensation for Smart NUX", The Journal of the Korea Institute of Electronic Communication Sciences, Vol. 7, No. 5, pp. 999-1004, 2012.
  5. Xin Du, Hongdong Li, and Yunfang Zhu, "Camera Lens Radial Distortion Correction Using Two-view Projective Invariants", Optic Letters, Vol. 36, No. 24, pp. 4734-4736, 2011. https://doi.org/10.1364/OL.36.004734
  6. Byung-Ik Kim, Dea-Hyeon Kim, Tae-Wuk Bae, Young-Choon Kim, Tae-Een Shim, Duk-Gyoo Kim, "An Automatic Mapping Points Extraction Algorithm for Calibration of the Wide Angle Camera", Journal of Korea Multimedia Society, Vol. 13, No. 3, pp. 410-416, 2010.
  7. Han-Seog Seo and Wha-Young Yim, "A Compensation for Distortion of Stereo-scopic Camera Image Using Neuro-Fuzzy Inference System", The Journal of the Korea Institute of Electronic Communication Sciences, Vol. 5, No. 3, pp. 262-268, 2010.
  8. Janne Heikkila and Olli Silven, "A Four-step Camera Calibration Procedure with Implicit Image Correction", in Proc. of Int'l Conf. on Computer Vision and Pattern Recognition, pp. 1106-1112, 1997.
  9. Young-Ho Yu and Si-Woong Jang, "Design and Implementation of 4-sided Monitoring System Providing Bird's Eye View in Car PC Environment", The Journal of The Korean Institute of Information and Communication Engineering, Vol. 16, No. 1, pp. 153-159, 2012. https://doi.org/10.6109/jkiice.2012.16.1.153
  10. Van-Toan Cao and Sang-Bock Cho, "A New Method Using Geometric Invariability for Lens Distortion Correction", Journal of The Institute of Electronics Engineers of Korea, Vol. 48SP, No. 6, pp. 115-123, 2011.
  11. Zhengyou Zhang, "A Flexible New Technique for Camera Calibration", IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 22, No. 11, pp. 1330-1334, 2000. https://doi.org/10.1109/34.888718
  12. Duane C. Brown, "Close-range Camera Calibration", Photogrammetric Engineering, Vol. 37, pp. 855-866, 1971.
  13. http://www.adobe.com/kr/products/photoshop.html
  14. http://www.acasoft.dk/acapixus/rectfish/index.htm