THORLABS BC207UV, Руководство по эксплуатации

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BC207 Series
Chapter 5: The Graphics User Interface (GUI)
Rev: 8.1, 10-Jan-2022
Page 38
© 2022 Thorlabs
5.5.3.6 Region of Interest
The maximum Region of Interest (ROI) is 2448 x
2048 pixel (full size) and the smallest 32 x 32 pixel.
The ROI depends on the settings for binning. With
the ROI parameter, the user can define a subarea
within the maximum available camera sensor sur-
face for data acquisition. Only image data of the se-
lected ROI are transmitted from the Camera Beam
Profiler to the PC so that a narrowed ROI size re-
duces bandwidth requirements and therefore in-
creases measurement speed (frames per second,
fps).
There are some ROI presets that can
be selected from the list.
To confirm, click to
-
this button applies the changes that
were made not only to the ROI, but
also to the
Center settings of the
ROI. By selecting a predefined ROI it
is automatically centered to the
sensor center. See the preview image for visualizing
the adjusted size which is displayed as a yellow rectangle. To shift the selected ROI within the
available sensor area click right into this rectangle and drag the mouse; the "Preset" name
changes immediately to User Defined.
User Defined ROI
A user defined ROI can be easily defined by drawing a rectangle into the preview image (click
left, hold down and draw a rectangle). The last preset value is replaced automatically by "User
Defined" and the chosen ROI size and position is displayed within the controls on the right.
These values can also be modified by entering the desired Width, Height, Left and Top values
into the appropriate controls. Its unit can be switched between pixels or µm.
Note
The ROI point of origin (0,0) is located in the upper left corner of the entire sensor area so that
'Left' and 'Top' describe the upper left ROI borders with respect to this corner. In contrast to
that, measurement coordinates X and Y are defined with respect to the center of the ROI, see
below.
Center
Any user defined ROI can be centered to either the sensor center or to the centroid of the
measured beam. The latter may be useful if the beam centroid is located far away from the
sensor center and the user defined ROI does not cover the sensor center.
When the measured beam is considerably smaller than the Camera Beam Profiler aperture, it
is advisable to limit the area captured by the camera. Reduce the image area by determining a
ROI that is well filled by the beam. However, it is not recommended to narrow ROI too much -
lower intensity areas surrounding the laser beam will be cut off! This may lead to incorrect nu-
merical results (for instance Beam Centroid position) or even prevent calculation of the beam
width because the selected clip level (default 13.5% of the peak intensity) is not reached within
the ROI.
Please enlarge the ROI when the beam under test does not fit to the selected ROI area. The
ROI height and width should be at least two times the beam width.
Note
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