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Journal of Zhejiang University SCIENCE C

, Volume 14, Issue 12, pp 930–940 | Cite as

An efficient projection defocus algorithm based on multi-scale convolution kernel templates

  • Bo Zhu
  • Li-jun Xie
  • Guang-hua Song
  • Yao Zheng
Article

Abstract

The focal problems of projection include out-of-focus projection images from the projector caused by incomplete mechanical focus and screen-door effects produced by projection pixilation. To eliminate these defects and enhance the imaging quality and clarity of projectors, a novel adaptive projection defocus algorithm is proposed based on multi-scale convolution kernel templates. This algorithm applies the improved Sobel-Tenengrad focus evaluation function to calculate the sharpness degree of intensity equalization and then constructs multi-scale defocus convolution kernels to remap and render the defocus projection image. The resulting projection defocus corrected images can eliminate out-of-focus effects and improve the sharpness of uncorrected images. Experiments show that the algorithm works quickly and robustly and that it not only effectively eliminates visual artifacts and can run on a self-designed smart projection system in real time but also significantly improves the resolution and clarity of the observer’s visual perception.

Key words

Projection focal Sobel-Tenengrad evaluation function Projector defocus Multi-scale convolution kernels 

CLC number

TP391 

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References

  1. Ashdown, M., Okabe, T., Sato, I., Sato, Y., 2006. Robust Content-Dependent Photometric Projector Compensation. Proc. Conf. on Computer Vision and Pattern Recognition Workshop. [doi:10.1109/CVPRW.2006.172]Google Scholar
  2. Bhasker, E., Juang, R., Majumder, A., 2007. Registration techniques for using imperfect and partially calibrated devices in planar multi-projector displays. IEEE Trans. Visual. Comput. Graph., 13(6):1368–1375. [doi:10.1109/TVCG.2007.70586]CrossRefGoogle Scholar
  3. Bimber, O., Emmerling, A., 2006. Multifocal projection: a multiprojector technique for increasing focal depth. IEEE Trans. Visual. Comput. Graph., 12(4):658–667. [doi:10.1109/TVCG.2006.75]CrossRefGoogle Scholar
  4. Bimber, O., Iwai, D., Wetzstein, G., Grundhöfer, A., 2008. The visual computing of projector-camera systems. Comput. Graph. Forum, 27(8):2219–2245. [doi:10.1111/j.1467-8659.2008.01175.x]CrossRefGoogle Scholar
  5. Brown, M., Majumder, A., Yang, R.G., 2005. Camera-based calibration techniques for seamless multiprojector displays. IEEE Trans. Visual. Comput. Graph., 11(2): 193–206. [doi:10.1109/TVCG.2005.27]CrossRefGoogle Scholar
  6. Brown, M.S., Song, P., Cham, T.J., 2006. Image Preconditioning for Out-of-Focus Projector Blur. Proc. IEEE Computer Society Conf. on Computer Vision and Pattern Recognition, p.1956–1963. [doi:10.1109/CVPR.2006.145]Google Scholar
  7. Grossberg, M.D., Peri, H., Nayar, S.K., Belhumeur, P.N., 2004. Making One Object Look Like Another: Controlling Appearance Using a Projector-Camera System. Proc. IEEE Conf. on Computer Vision and Pattern Recognition, 1:452–459. [doi:10.1109/CVPR.2004.1315067]Google Scholar
  8. Grosse, M., Wetzstein, G., Grundhöfer, A., Bimber, O., 2010. Coded aperture projection. ACM Trans. Graph., 29(3), Article 22, p.1–12. [doi:10.1145/1805964.1805966]CrossRefGoogle Scholar
  9. ITU, 2002. Methodology for the Subjective Assessment of the Quality of Television Pictures. ITU Recommendation BT 500-11. International Telecommunication Union.Google Scholar
  10. Ladha, S., Smith-Miles, K., Chandran, S., 2011. Projection Defocus Correction Using Adaptive Kernel Sampling and Geometric Correction in Dual-Planar Environments. IEEE Computer Society Conf. on Computer Vision and Pattern Recognition Workshops, p.9–14. [doi:10.1109/CVPRW.2011.5981686]Google Scholar
  11. Nagase, M., Iwai, D., Sato, K., 2011. Dynamic defocus and occlusion compensation of projected imagery by model-based optimal projector selection in multi-projection environment. Virtual. Real., 15(2–3):119–132. [doi:10.1007/s10055-010-0168-4]CrossRefGoogle Scholar
  12. Nayar, S.K., Peri, H., Grossberg, M.D., Belhumeur, P.N., 2003. A Projection System with Radiometric Compensation for Screen Imperfections. Proc. ICCV Workshop on Projector-Camera Systems, p.1–8.Google Scholar
  13. NTT, 1999. Video Quality Assessment Methods: 1.5.(5). Citing Electronic Sources of Information. Network Technology Laboratories. Available from http://www.ntt.co.jp/qos/qoe/eng/technology/visual/01_5_5.html.Google Scholar
  14. Oyamada, Y., Saito, H., 2009. Blind Deconvolution Based Projector Defocus Removing with Uncalibrated Projector-Camera Pair. IEEE Int. Workshop on Projector-Camera Systems.Google Scholar
  15. Raskar, R., Welch, G., Cutts, M., Lake, A., Stesin, L., Fuchs, H., 1998. The Office of the Future: a Unified Approach to Image-Based Modeling and Spatially Immersive Displays. Proc. 25th Annual Conf. on Computer Graphics and Interactive Techniques, p.179–188. [doi:10.1145/280814.280861]Google Scholar
  16. Wang, X.H., Hua, W., Bao, H.J., 2007. Global color correction for multi-projector tiled display wall. J. Comput.-Aided Des. Comput. Graph., 19(1):96–101 (in Chinese).Google Scholar
  17. Xie, L.J., Zheng, Y., Yang, T.J., Gao, W.X., Pan, N.H., 2007. SimWall: a practical user-friendly stereo tiled display wall system. J. Zhejiang Univ.-Sci. A, 8(4):596–604. [doi:10.1631/jzus.2007.A0596]CrossRefGoogle Scholar
  18. Yang, T.J., Xie, L.J., Zheng, Y., Gao, W.X., Pan, N.H., 2007. Construction of a large scale stereo display wall system. J. Comput.-Aided Des. Comput. Graph., 19(8):953–959 (in Chinese).Google Scholar
  19. Zhang, L., Nayar, S., 2006. Projection defocus analysis for scene capture and image display. ACM Trans. Graph., 25(3):907–915. [doi:10.1145/1141911.1141974]CrossRefGoogle Scholar
  20. Zhang, Z.Y., 2000. A flexible new technique for camera calibration. IEEE Trans. Pattern Anal. Mach. Intell., 22(11): 1330–1334. [doi:10.1109/34.888718]CrossRefGoogle Scholar
  21. Zhu, B., Xie, L.J., Wang, Q.H., Yang, T.J., Zheng, Y., 2011a. An Intelligent Projection System Adapted to Arbitrary Surfaces. First Int. Conf. on Instrumentation, Measurement, Computer, Communication and Control, p.293–298. [doi:10.1109/IMCCC.2011.80]CrossRefGoogle Scholar
  22. Zhu, B., Xie, L.J., Yang, T.J., Wang, Q.H., Zheng, Y., 2011b. A novel radiometric projector compensation algorithm based on Lambertian reflection model. SPIE, 8004:80040I-1–80040I-5. [doi:10.1117/12.901092]CrossRefGoogle Scholar
  23. Zhu, B., Xie, L.J., Yang, T.J., Wang, Q.H., Zheng, Y., 2012. An adaptive calibration algorithm for projected images in everyday environment. J. Comput.-Aided Des. Comput. Graph., 24(7):941–948 (in Chinese).Google Scholar

Copyright information

© Journal of Zhejiang University Science Editorial Office and Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Bo Zhu
    • 1
    • 2
  • Li-jun Xie
    • 1
    • 2
  • Guang-hua Song
    • 1
    • 2
  • Yao Zheng
    • 1
    • 2
  1. 1.School of Aeronautics and AstronauticsZhejiang UniversityHangzhouChina
  2. 2.Center for Engineering and Scientific ComputationZhejiang UniversityHangzhouChina

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