Jump to content United States-English
HP.com Home Products and Services Support and Drivers Solutions How to Buy
» Contact HP

HP.com home

Solving the Correspondence Problem with Coded Light Patterns (LUMA)


HP Labs

» Research
» News and events
» Technical reports
» About HP Labs
» Careers @ HP Labs
» People
» Worldwide sites
» Downloads
Content starts here

Establishing reliable dense correspondences is crucial for many 3D and projector-related applications.  LUMA proposes using coded light patterns to directly obtain the correspondence mapping between a projector and a camera without any searching or calibration. The technique consists of encoding positional information of projector space and capturing the projected result.  Unlike using 3x3 planar perspective transforms or homographies, LUMA provides a general point-to-point mapping between coordinate systems that can handle nonlinear camera lens distortion and multiple objects in the scene.  In contrast to traditional image-based approaches, LUMA does not rely on consistent textures across frames.  The technique naturally extends to efficiently solve the traditionally difficult multiframe correspondence problem across any number of cameras and/or projectors. Furthermore, it automatically determines visibility across all cameras in the system and scales linearly in computation with the number of cameras.

The proposed technique, along with the resulting correspondences, has implications in many computer vision and image processing applications, especially those that require multiframe correspondences.  The technique has been shown to be particularly effective in addressing a variety of problems including camera calibration, computing epipolar geometry, facilitating image-based stereo, single-camera view interpolation, dual- and multi-camera view synthesis at interactive rates, and 3-D shape recovery.  Because of duality, LUMA can also further improve many projector-based applications including automatic keystone correction.

For more technical details, please refer to the following papers:

  • N. L. Chang, "Creating Interactive 3-D Media with Projector-Camera Systems," SPIE Visual Communications and Image Processing Conference, San Jose, CA, vol. 5308, pp. 850--861, 20--22 January 2004.  Also appears as HP Labs Technical Report HPL-2003-229, November 2003 (pdf download).
  • N. L. Chang, "Efficient Dense Correspondences using Temporally Encoded Light Patterns," IEEE International Workshop on Projector-Camera Systems, Nice, France, 12 October 2003.  Also appears as HP Labs Technical Report HPL-2003-189, 4 September 2003 (pdf download).
  • N. L. Chang, "Interactive 3-D Media with Structured Light Scanning," HP Labs Technical Report HPL-2003-112, 29 May 2003 (pdf download).
  • N. L. Chang, "A Multi-camera and Projected Light System for Fast and Efficient 3-D Media Creation," HP Labs Technical Report HPL-2002-306, October 2002 (internal).


For more information about the technology, please contact Nelson Chang (nelson.chang @ hp.com) at Imaging Technology Dept., HP Labs.

Printing and Imaging Research Center
  » PIRC web site
» Imaging Systems Laboratory
  » Projects


example of using luma for view synthesis

example of using luma for 3-d modeling

Printable version
Privacy statement Using this site means you accept its terms Feedback to HP Labs
© 2009 Hewlett-Packard Development Company, L.P.