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Chapter 3
NI Smart Camera Image Sensor
Binning
Binning can improve the light sensitivity of the sensor by treating adjacent pixels as a single
pixel. Binning allows the image sensor to collect more electrons per pixel, which reduces the
amount of required light and exposure time. Binning results in higher frame rates and lower
spatial resolution in the vertical direction. The NI Smart Camera supports 1 × 2 binning.
Figure 3-3 illustrates what happens to the sensor output during binning.
Figure 3-3.
Binning
Gain
Gain is a multiplier applied to the analog signal prior to digitization. Increasing the gain
increases the amplitude of the signal. Gain allows you to trade off between making smaller
signals more visible at the cost of increased noise and no longer being able to differentiate
between larger signals. For most applications, the NI Smart Camera default gain setting
optimizes the balance between small signals and large signals.
Figure 3-4 shows what happens when gain is applied to a signal.
Figure 3-4.
Effect of Gain on the Video Signal
In Figure 3-4a, low gain has been applied to the signal. The pixel values in the image are grouped
close together. In Figure 3-4b, medium gain has been applied to the signal; there are now more
notable differences in pixel value within the image. In Figure 3-4c, high gain has been applied
to the signal; at high gain, mid-range and bright portions of the image are now both represented
a
No Binning
b
Binning
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Low Gain
b
Medium Gain
c
High Gain
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b
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Summary of Contents for ISC-1762
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