Journal of the Korea Computer Graphics Society (한국컴퓨터그래픽스학회논문지)

Korea Computer Graphics Society (한국컴퓨터그래픽스학회)
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Regeneration of Plausible Lighting using a Specular Sphere in Augmented Reality

증강현실에서의 반사구를 활용한 사실적 조명 생성

  • Lee, Seok-Jun (School of Computer Science and Engineering, College of IT Engineering, Kyungpook National University) ;
  • Jung, Soon-Ki (School of Computer Science and Engineering, College of IT Engineering, Kyungpook National University)
  • 이석준 (경북대학교 IT대학 컴퓨터학부) ;
  • 정순기 (경북대학교 IT대학 컴퓨터학부)
  • Received : 2011.06.30
  • Accepted : 2011.08.26
  • Published : 2011.09.01
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Abstract

This paper presents a practical method to estimate the directions of light sources in real environment, using a mirror sphere placed on a set of known natural features in augmented reality. For the stable result of static lighting, we take the multiple images around the sphere and estimate the principal light directions of the vector clusters for each light source in realtime. We also estimate the moving illuminant for changes of the scene illumination, and augment the virtual objects onto the real image with the proper highlighting and shadows. The proposed method of this paper can be applied to augmented reality visualization without any previous information respecting the environmental illuminations.

논문에서는 마커리스 증강현실 가시화에서 반사구(mirror-sphere)를 이용하여 실제 환경의 광원위치를 추정한 결과를 증강되는 가상객체에 적용하는 방법을 제안한다. 고정된 환경조명의 안정적인 추정을 위해, 카메라를 반사구 주위를 돌며 촬영하여 반사구에 대한 다중 영상을 획득한 후, 각 광원 벡터 클러스터의 주광원 방향을 추정한다. 본 논문에서는 환경 조명의 광원방향 추정과 함께 움직이는 광원에 대한 광원방향도 추정함으로써, 실제 조명환경을 증강되는 가상 객체에 반영하여 사실적인 음영효과와 그림자를 생성한다. 본 논문에서 제안하는 조명 추정 방법은 조명 환경에 대한 어떠한 사전 정보 없이도 즉각적으로 증강현실 가시화에 적용할 수 있다.

Keywords

References

  1. F. N athan, "A survey of light source detection methods," Mini-Project for CMPUT 603, (Online-published), 2003.
  2. Q. H. Jin-tao Ma, Ya Zhou and Y Zhang, "Marker cube and probe sphere based illuminant detection algorithm," in Int. Symp. Photoelectronic Detection and Imaging, 2007.
  3. Y. Zhang and Y.-H. Yang, "Multiple illuminant direction detection with application to image synthesis," IEEE Trans. on Pattern Analysis and Machine Intelligence, vol. 23, pp. 915-920, August 2001. https://doi.org/10.1109/34.946995
  4. Y. Feng, "Estimation of light source environment for illumination consistency of augmented reality," in Proc. the 2008 Congress on Image and Signal Processing, vol. 3. IEEE Computer Society, 2008, pp. 771-775.
  5. M. Aittala, "Inverse lighting and photorealistic rendering for augmented reality," Visual Computer, vol. 26, pp. 669-678, June 2010. https://doi.org/10.1007/s00371-010-0501-7
  6. P. Debevec, "Rendering synthetic objects into real scenes: Bridging traditional and image-based graphics with global illumination and high dynamic range photography," in Proc. the 25th Annual Conference on Computer Graphics and Interactive Techniques, ser. SIGGRAPH '98. ACM, 1998, pp. 189-198.
  7. T. Okatani and K. Deguchi, "Estimation of illumination distribution using a specular sphere," in Proc. 15th Int. Conf. on Pattern Recognition, vol. 3, 2000, pp. 592 -595 vol.3.
  8. M. Kanbara and N. Yokoya, "Real-time estimation of light source environment for photorealistic augmented reality," in 17th Int. Conf. on Pattern Recognition (ICPR '04), ser. ICPR '04, vol. 2. Washington, DC, USA: IEEE Computer Society, 2004, pp. 911-914. [Online]. Available: http://dx.doi.org/10.1109/ICPR.2004.735
  9. M. H. Peter Supan, Ines Stuppacher, "Image based shadowing in real-time augmented reality," Virtual Reality, vol. 5, pp. 1-7, 2006.
  10. M. Knecht, C. Traxler, O. Mattausch, W. Purgathofer, and M. Wimmer, "Differential instant radiosity for mixed reality," in Proc. 9th IEEE Int. Symp. on Mixed and Augmented Reality (ISMAR '10), 2010.
  11. M. Hailer, S. Drab, and W. Hartmann, "A real-time shadow approach for an augmented reality application using shadow volumes," in Proc. the ACM Symp. on Virtual Reality Software and Technology, ser. VRST '03. New York, NY, USA: ACM, 2003, pp. 56-65.
  12. M. N. Claus B. Madsen, "Towards probe-less augmented reality," in Int. Con! on Graphics Theory and Applications(GRAPP), 2008, pp. 255-261.
  13. J. M. Frahm, K. Koeser, D. Grest, and R. Koch, "Markerless augmented reality with light source estimation for direct illumination," in Conf. on Visual Media Production CVMP, 2005.
  14. S. Lee and S. K. Jung, "Estimation of illuminants for plausible lighting in augmented reality," in Int. Symp. on Ubiquitous Virtual Reality (ISUVR '11), 2011.
  15. D. G. Lowe, "Distinctive image features from scale-invariant keypoints," Int. J. Comput. Vision, vol. 60, pp. 91-110, November 2004.
  16. R. I. Hartley and A. Zisserman, Multiple View Geometry in Computer Vision, 2nd ed. Cambridge University Press, ISBN: 0521540518, 2004.
  17. 이석준, 장재석, and 정순기, "동영상 프레임간의 상호일관성을 이용한 단일 카메라 자세 안정화 기법," in 한국HCI학회 학술대회(HCI'11), 2011.
  18. ARToolKit, HIT Lab. [Online]. Available: http://www.hitl.washington.edu/artoolkit/