Basler L301kc, Инструкция по установке и эксплуатации

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Operation and Features
3-22 Basler L301kc
DRAFT
3.6 Gain and Offset
The major components in the camera electronics in-
clude: a CCD sensor with three lines of pixels, a vari-
able gain control (VGC) for each line, and an analog
to digital converter (ADC) for each line (see Figure 3-
1). The pixels in each line of the CCD sensor output
an analog voltage signal when exposed to light. The
analog voltage output from each line is amplified by a
VGC and transferred to an ADC which converts the
output to a digital signal.
Two parameters, gain and offset, are associated with
each VGC. As shown in Figure 3-20 and Figure 3-21,
increasing or decreasing the gain increases or de-
creases the amplitude of the signal that is input into
the ADC. Increasing or decreasing the offset moves
the signal up or down the measurement scale but
does not change the signal amplitude.
For most applications, black should have a gray
value of 1 and white should have a gray value of 254
(in 8 bit output modes) or 1023 (in 10 bit output
mode). Attempt to achieve this by varying exposure
and illumination rather than changing the camera’s
gain. The default gain is the optimal operating point
(minimum noise) and should be used if possible.
Internally, the
L301
kc
processes red, green and blue
pixels using three different VGCs. If the white bal-
ance of the images produced by the camera is not
correct for your application, you can change the white
balance by adjusting the gain on the red, green or
blue pixels.
L
Because increasing gain increases both signal and noise, the signal to noise ratio
does not change significantly when gain is increased.
Figure 3-20: Gain
Figure 3-21: Offset