© National Instruments
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5-3
NI 17xx User Manual
its peak responsiveness. It also helps determine what, if any, filters your application might
require to remove undesired wavelengths of light from the scene.
Refer to Appendix A,
Specifications
, to find the normalized spectral response curves for the
image sensors.
Partial Scan Mode
Partial scan mode is a method of obtaining higher frame rates by reading out only a portion of
the image from the sensor. Partial scan is frequently used when an application requires higher
speed but less resolution than the sensor offers in full scan mode. The NI Smart Camera supports
1/2 scan and 1/4 scan. In 1/2 scan, shown in Figure 5-2b, one half of the image is read out from
the center of the sensor and the rest of the image is discarded to enable a faster start of the next
frame. In 1/4 scan, only one quarter of the image is read out. Figure 5-2 illustrates the portion of
the sensor exposed during partial scanning.
Figure 5-2.
Partial Scan Modes
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 5-3 illustrates what happens to the sensor output during binning.
Figure 5-3.
Binning
a
Full Scan
b
1/2 Scan
c
1/4 Scan
a
No Binning
b
Binning
a
b
c
a
b
