An image data processing method includes receiving, from an image sensor, frame image data of a plurality of frames; receiving a plurality of control rules comprising a respective control rule for each of the frames, wherein each of the control rules identifies one of a plurality of process regions and one of a plurality of object detectors; identifying a region of interest in each frame by a location and a category, comprising applying the object detector identified by the respective control rule to the respective frame image data in the process region identified by the respective control rule; identifying a final region of interest based on the identified regions of interest; and reporting the final region of interest.