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[H]
Halogen lamp
Light source with halogen gas in the bulb. When a halogen lamp is lit, the halogen gas and vapor-
ized tungsten combine. When the filament is heated, these combined particles reattach to the
tungsten, in stead of being deposited on the glass bulb, so that the original brightness of the lamp is
maintained throughout its life span.
High frequency lighting
If a fluorescent lamp is powered by commercial electricity, it will flicker at 50 Hz or 60 Hz. Since the
CCD scans images at 60 Hz, the brightness of the image may fluctuate due to the flickering of the
fluorescent lamp.
By increasing frequency used to power the fluorescent lamp (employing a high frequency light), this
type interference is eliminated and a stable image can be obtained.
Histogram widening
This is a method to widen the histogram for an image in which the histogram only occupies part of
the available scale, thus improving the contrast. For example, in figure 1, the gray level values are
concentrated in the [a, b] part of the range, and the [0, a] and [b, Zm] parts of the range are not used
(the histogram is not expanded to use all of the gray scale values). This image has low contrast,
since the image does not use the full dynamic range efficiently. Expand the histogram to cover the
entire range of gray scale values, as shown in figure 2. The contrast will be improved.
a
b
0
Gray level
1 Low contrast image
Hue
Color tone, or the property by which the sense of vision can distinguish between objects such as
red, blue, or green.
[I]
Illumination monitor alarm density setting
The "illumination (light level) monitor" is a function which automatically monitors the environmental
lighting conditions when measuring objects.
If the illuminance exceeds the alarm density setting, the IV-C35M will display an alarm message.
Interline transfer system
The interline transfer system is a system for transferring electrical charges from the CCD receiving
elements to the readout matrix.
The frame transfer system is a system for transferring electrical charge which uses the photo sensi-
tive area to read out the charges. This system is subject to smearing noise since the area is used for
both receiving and transferring the image.
Island
An "island" is a separate area which is created after labeling (object identification) process of the
binary image.
m
Z
0
Gray level
2 Good contrast image
G-7
m
Z
Glossary
G
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