8.Features
© 2023 China Daheng Group, Inc. Beijing Image Vision Technology Branch 85
Offset is the offset value that relative to the upper left corner of the image. The step of AAROIOffsetX and
AAROIWidth is 16. The step of AAROIOffsetY and AAROIHeight is 2. The setting of the AAROI depends
on the size of the current image and cannot exceed the range of the current image. That is to say, assuming
the Width and Height are parameters for users captured image, then the AAROI setting need to meet the
condition 1:
AAR AAROIOffsetX≤Width
AARO AAROIOffsetY≤Height
If condition 1 is not met, the user cannot set the ROI.
The default value of ROI is the entire image, you can set the ROI according to your need. Where the
minimum value of AAROIWidth can be set to 16, and the maximum value is equal to the current image
width. The minimum value of AAROIHeight can be set to 16, and the maximum value is equal to the current
image height, they are all need to meet the condition1.
For example: the current image width is 1024, the height is 1000, and then the ROI setting is:
AAROIOffsetX
＝
100
AAROIOffsetY
＝
50
AAROIWidth
＝
640
AAROIHeight
＝
480
The relative position of the ROI and the image is shown in Figure 8-33.
ROI
1024
1000
ROI
640
480
100
50
Figure 8-33 An example for the relative position between the ROI and the current image
8.3.6.2.
Auto Gain
The auto gain can adjust the camera's gain automatically, so that the average gray value in AAROI is
achieved to the expected gray value. The auto gain can be controlled by "Once" and "Continuous" mode.
When using the "Once" mode, the camera adjusts the image data in the AAROI to the expected gray value
once, then the camera will turn off the auto gain feature. When using the "Continuous" mode, the camera
