7
Radiometry
and Computer Vision*
•From Sonka, Hlavac, and
Boyle, Image Processing, Analysis, and
Machine
Vision, ITP, 1999.
• Radiometry
is a branch of physics that deals with the
measurement of the flow and transfer of
radiant energy.
• Radiance
is the power of light that is emitted from a
unit surface area into some spatial
angle;
the corresponding photometric term is brightness.
• Irradiance is the amount of energy that an image-
capturing device gets per unit of an
efficient sensitive
area of the camera. Quantizing it gives
image gray tones.