
41
8.1
Area of interest (AOI)
The image sensor on the camera has a defined resolution. This indicates the maximum
number of lines and pixels per line that the recorded image may have.
However, often only a certain section of the entire image is of interest. The amount of
data to be transferred can be decreased by limiting the image to a section when
reading it out from the camera. At a lower vertical resolution the sensor can be read out
faster and thus the frame rate is increased.
L
The setting of AOIs is supported only in video Format_7.
While the size of the image read out for most other video formats and modes is fixed by
the IIDC specification, thereby determining the highest possible frame rate, in
Format_7 the user can set the “upper left corner” and “width and height” of the section
(Area of Interest) he is interested in to determine the size and thus the highest
possible frame rate.
Setting the AOI is done in the IMAGE_POSITION and IMAGE_SIZE registers.
Attention should be paid to the increments entered in the UNIT_SIZE_INQ and
UNIT_POSITION_INQ registers when configuring IMAGE_POSITION and IMAGE_SIZE.
IMAGE_POSITION and IMAGE_SIZE contain in the respective bits values for the column
and line of the upper left corner and values for the width and height.
Figure 33 Area of Interest