On the relationship between radiance and irradiance: determining the illumination from images of a convex Lambertian object
JOSA A, Vol. 18, Issue 10, pp. 2448-2459 (2001)
http://dx.doi.org/10.1364/JOSAA.18.002448
Acrobat PDF (358 KB)
Abstract
We present a theoretical analysis of the relationship between incoming radiance and irradiance. Specifically, we address the question of whether it is possible to compute the incident radiance from knowledge of the irradiance at all surface orientations. This is a fundamental question in computer vision and inverse radiative transfer. We show that the irradiance can be viewed as a simple convolution of the incident illumination, i.e., radiance and a clamped cosine transfer function. Estimating the radiance can then be seen as a deconvolution operation. We derive a simple closed-form formula for the irradiance in terms of spherical harmonic coefficients of the incident illumination and demonstrate that the odd-order modes of the lighting with order greater than 1 are completely annihilated. Therefore these components cannot be estimated from the irradiance, contradicting a theorem that is due to Preisendorfer. A practical realization of the radiance-from-irradiance problem is the estimation of the lighting from images of a homogeneous convex curved Lambertian surface of known geometry under distant illumination, since a Lambertian object reflects light equally in all directions proportional to the irradiance. We briefly discuss practical and physical considerations and describe a simple experimental test to verify our theoretical results.
© 2001 Optical Society of America
[Optical Society of America ]
OCIS Codes
(150.0150) Machine vision : Machine vision
(150.2950) Machine vision : Illumination
Citation
Ravi Ramamoorthi and Pat Hanrahan, "On the relationship between radiance and irradiance: determining the illumination from images of a convex Lambertian object," J. Opt. Soc. Am. A 18, 2448-2459 (2001)
http://www.opticsinfobase.org/josaa/abstract.cfm?URI=josaa-18-10-2448
You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Log in to access OSA Member Subscription
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Log in to access OSA Member Subscription
You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Log in to access OSA Member Subscription
Related Journal Articles 
- Reflectors for uniform far-field irradiance: fundamental limits and example of an axisymmetric solution (AO)
- What shadows reveal about object structure (JOSAA)
- Color invariant for daylight changes: relaxing the constraints on illuminants (JOSAA)
- Spectral invariance under daylight illumination changes (JOSAA)
- Color-signal filtering in the Fourier-frequency domain (JOSAA)
Related Conference Papers
« Previous Article | Next Article »
OSA is a member of 