zoom speed should depend on offset of target

[maiermic]

If the target is in the center, it is safe to zoom in fast. However, if the target is far from the center (e.g. near the left edge of the camera image), the target might be lost if the camera zooms in too much, before the camera rotated/tilted enough to catch up with the target.

It is less likely that the target is lost if the camera zooms in more slowly, because then there is more time to rotate/tilt. It might be even better/safer to do not zoom at all if the target is near the edge of the camera image and wait to zoom till the target is closer to the center. However, the target might also be lost if it gets too small (is too far away) for object detection to work (reliable). Hence, the threshold to start zooming should maybe also depend on the target size (in the image), i.e. if the target is smaller, the target may be further away from the center to (still) zoom in.

On the other hand, the camera should zoom out faster if the target is far from the center.

[maiermic]

Several zoom-in modes have been added. The used zoom-in mode is currently hard coded. Users should be able to select a mode in the UI.