Banner PresencePLUS P4 Series - Manual (Page 248)

barrel distortions
An image appearing to bulge outward on all sides, like a
barrel. This is caused by a decrease in effective magnification,
as points in the image move a way from the image center.
beam splitter
A device for dividing a light beam into two or more separate
beams.
bimodal
Histogram distribution of values with two peaks.
binary system
A vision system that creates a digitized image of an object in
which each pixel can have one of only two values, such as
light/dark, or zero/one.
Blob
cronym for Binary Large OBject. A connected region in a
binary image.
blooming
The "smearing" of regions of the image where the detected
brightness is at an excessive level for the receiving element,
due to electronic contamination from neighboring bright pixels.
C
c-mount
Threaded lens mount developed from 16 mm movie work.
used extensively for closed-circuit television. The threads
have a major diameter of 1" and a pitch of 32 threads per
inch. The flange focal distance is 0.69".
calibration
The relationship between the output of a measuring instrument
and some fiducial mark, an accepted standard of
measurement, or other reference datum for the purpose of
reporting future results relative to the reference.
centroid
The X and Y pixel coordinates of the center of mass in a two
dimensional Blob.
collimated
A beam of light in which all optical rays are parallel.
contrast
The range of difference between light and dark values in an
image.
correlation
A process whereby two image segments are compared to
determine their similarity, or to find the position at which
optimal similarity exists.
D
dark field
An illumination technique supplying the illumination at a
shallow (grazing) angle to the surface of the work piece.
Ordinarily only a negligible amount of light reflects into the
Sensor. Specular reflections occur off any abrupt surface
irregularities, and are detectable in the image.
depth of field
The in-focus range of an imaging system. Measured from the
distance behind an object to the distance in front of the object,
with all objects appearing in focus.
depth of focus
The range of lens-to-image plane distance having the image
formed by the lens appearing in focus.
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