Banner PresencePLUS P4 Series - Manual (Page 249)

deslant
In order for the OCV/OCR Vision tool to box correctly, there
must be a minimum of a 1 pixel-wide column between
characters. If the characters are slanted in such a way that
they overlap in ths 1 pixel-wide column, then the image may
need to be manipulated, or deslanted, so that the image can
box correctly.
diffuse
The process of redirecting incident light over a range of
scattered angles, while reflecting from or transmitting through
a material.
distortion
Undesired change in the shape of an image or waveform from
the original object or signal.
edge
A change in pixel values exceeding some threshold between
two adjacent regions of relatively uniform values. Edges
correspond to changes in brightness corresponding to a
discontinuity in surface orientation, reflectance, or illumination.
f/stop (or f/number
Ratio of the focal length of a lens to the diameter of its
opening. Increasing or decreasing an exposure by one f/stop
doubles or halves the amount of light allowed through the
lens.
feature
Any characteristic descriptive of an image or a region in an
image.
feature extraction
The process of generating a set of descriptors or characteristic
attributes from an image.
fiducial mark
A mark defining a datum point or standard of positional
reference used as a basis for calculation or measurement.
field of view (FOV)
The area of object space imaged at the focal plane of a lens.
fluorescent lamp
A lamp that produces light by exciting a phosphor with a
plasma, with the phosphor re-emitting the energy as light.
focal length
The distance from a lens’ principal point to the corresponding
focal point. Also referred to as the equivalent focal length and
the effective focal length.
front lighting
An arrangement in which the object is illuminated and viewed
from the same side.
G
gradient magnitude
The rate-of-change of pixel intensities over a small local
neighborhood.
gray scale
Standardized variations of values from white, through shades
of gray, to black in a digitized image with black assigned the
value of zero and white the value of 255.
H
halogen
A gas, such as iodine, placed inside an incandescent lamp
to gather the evaporated filament off the bulb and redeposit
it back onto the filament.
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