9. CONFIGURATION
Maximum exposure time: Depending on your selected frame rate, you might
need to decrease the maximum exposure time to reach the desired rate.
The value for the maximum exposure time should always be smaller than
the time between two frames.
Maximum gain: Just like for the exposure time, it is also possible to con-
strain the maximum allowed gain. Constraining the gain can improve
image processing results for situations with high sensor noise.
9.6.2 Manual Settings
If the automatic adjustment is deactivated in the mode selection, the exposure
time and/or gain can be manually set to xed values in this section.
9.6.3 ROI Settings
Rather than performing the adjustment with respect to the average intensity of
the complete image, you can compute the average intensity only on a region of
interest. Enable `use ROI for adjustment' in that case. `Oset X' and `Oset
Y' describe the region's center position relative to the image center. `Width
ROI' and `Height ROI' let you adjust the spatial extension of the ROI. The
ROI must be completely contained in the image. If this is not the case, the
ROI will be cropped automatically.
9.7 Trigger / Pairing
The `trigger / pairing' page that is shown in Figure 18 allows for a conguration
of the trigger output and frame pairing settings. Frame pairing refers to the
process of identifying which left and right camera frames were recorded at the
same time. You can specify a maximum time dierence that is allowed for this
pairing process. Only frames whose time stamps do not dier by more than
this maximum dierence can form an image pair.
If the cameras provide high resolution images or if they have a low pixel
transfer speed, it is recommended to increase the maximum time dierence.
As a general guideline, we recommend setting half of the time delay between
two frames as the maximum time dierence.
This page also allows for a conguration of SceneScan's trigger port. As
described in Section 7.7, SceneScan features a trigger port that provides access
to up to two trigger signals. The two trigger signals, Trigger 0 and Trigger 1,
can be enabled or disabled by selecting the respective check boxes.
For Trigger 0 it is possible to select a frequency between 0.1 and 200 Hz and
an arbitrary pulse width in milliseconds. The polarity of the generated trigger
signal is active high. If the checkbox `use trigger time as timestamp' is selected,
then the trigger time is transmitted as timestamp with each processing result.
Please make sure that the cameras do not skip any trigger signals, as in this
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