Region

The relevant region of interest used for evaluation should be as large as necessary and as small as possible.
A small, precisely defined area results in faster evaluation and a higher refresh rate. This allows for faster application runtimes because image recording and processing are quicker. Furthermore, object or feature detection is more reliable because fewer noise pixels can occur within the evaluated area.
The object to be detected must lie fully within the selected area, because reliable object detection cannot otherwise be assured.