User`s manual

Features
144 Basler aviator Camera Link
Setting the Image AOI Using Direct Register Access
To set the AOI width and height via direct register access:
 Set the value of the Width register.
 Set the value of the Height register.
For more information about changing settings via direct register access, see Section 4 on page 45.
7.10.2 Prelines
As you work with the camera’s AOI feature, you may
notice that in some situations dark areas appear near the
top and the bottom of acquired images as shown in
Figure 36. (The image in the figure was acquired using a
light gray test pattern.)
These dark areas typically will not be present when large
AOIs are used, but will become more noticeable when the
AOI height is smaller. The effect will be most noticeable
when the AOI height is very small. The effect will be
especially apparent if the area of the sensor outside of the
AOI is very brightly illuminated.
The prelines feature is designed to minimize this effect.
The minimum and maximum settings for the Prelines
parameter depend on your camera model as shown in
Table 12. Higher prelines settings result in better
elimination of any dark areas at the top and bottom of the
acquired images. At the highest setting, the prelines feature will minimize or eliminate these dark
areas even when the AOI is very small.
There is a trade-off when using the prelines feature. As mentioned earlier in this section, the
camera’s maximum allowed frame rate will typically increase as the height of the AOI is made
smaller. Using the prelines feature impacts the relationship between the AOI height and the
maximum frame rate. When you use a large prelines setting, you will see less of an increase in the
maximum allowed frame rate as you make the AOI height smaller.
Camera Model Min Setting Max Setting
avA1000-120km/kc 1 96
avA1600-65km/kc 1 192
avA1900-60km/kc 1 192
avA2300-30km/kc 1 192
Table 12: Minimum and Maximum Preline Settings
Fig. 36: Dark Areas in Small AOI