Conference Paper

A Planar Light Probe

University of California, San Diego
DOI: 10.1109/CVPR.2006.37 Conference: Computer Vision and Pattern Recognition, 2006 IEEE Computer Society Conference on, Volume: 2
Source: DBLP


We develop a novel technique for measuring lighting that exploits the interaction of light with a set of custom BRDFs. This enables the construction of a planar light probe with certain advantages over existing methods for measuring lighting. To facilitate the construction of our light probe, we derive a new class of bi-directional reflectance functions based on the interaction of light through two planar surfaces separated by a transparent medium. Under certain assumptions and proper selection of the two surfaces, we show how to recover Fourier series coefficients of the incident lighting parameterized over the plane. The results are experimentally validated by imaging a sheet of glass with spatially varying patterns printed on either side.

Full-text preview

Available from:
  • Source
    • "They employed a pair of reference spheres as light probes and introduced the difference sphere that can be acquired by differencing the intensities of two image regions of the reference spheres. Alldrin and Kriegman (2006) developed a planar light probe for measuring low frequencies of the lighting. Their method is based on the interaction of light through two planar surfaces separated by a transparent medium . "
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a method to recover the reflectance of objects and the parameters of multiple lights using a 3D image acquired by a depth sensor and a stereo intensity pair. Experimental evaluation shows the ability to recover varying diffuse and constant specular reflectance parameters from object images, and simultaneously the locations and intensities of up to three distinct light sources.
    Pattern Recognition Letters 08/2008; 29(11-29):1639-1647. DOI:10.1016/j.patrec.2008.04.007 · 1.55 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Creating uniform lighting for archival-quality document acquisition remains a non-trivial problem. We propose a novel method for automatic photometric correction of non- planar documents by estimating a single, point light-source using a simple light probe. By adding a simple piece of folded white paper with a known 3D surface to a scene, we are able to extract the 3D position of a light source, auto- matically perform white balance correction, and determine areas of poor illumination. Furthermore, this method is designed with the purpose of adding it to an already im- plemented document digitization pipeline. To justify our claims, we provide an accuracy analysis of our correction technique using simulated ground-truth data which allows individual sources of error to be determined and compared. These techniques are then applied on real documents that have been acquired using a 3D scanner.
    2007 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR 2007), 18-23 June 2007, Minneapolis, Minnesota, USA; 01/2007
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a fast, low-cost technique to gather high-contrast 'relightable' photographs of desktop-sized objects. Instead of an elaborate light stage, we follow Mohan et al.; we place the object and a digitally steered spotlight inside a white cardboard box, aim the spotlight at the box interior, and move the spot to light the object from N repeatable lighting directions. However, strong ambient lighting from box interreflections causes 'shallow' shadows and reduces contrasts in all basis images. We show how to remove this ambient lighting computationally from the N images, by measuring an N ×N matrix of coupling factors between lighting directions using a mirrorsphere light probe. This linear method, suitable for any light stage, creates physically accurate 'deep shadow' basis images, yet imposes only a modest noise penalty, and does not require external light metering or illumination angle measurements. Results from our demonstration system support these claims.
    Proceedings of SPIE - The International Society for Optical Engineering 03/2008; 6810. DOI:10.1117/12.766949 · 0.20 Impact Factor
Show more