I've used a similar approach to save debug images in video stream processing system that basically scans vehicles going near the camera. Since the length and sp

I've used a similar approach to save debug images in video stream processing system that basically scans vehicles going near the camera. Since the length and speed of vehicles is varying, memory is constrained, and keeping too many images of each vehicles isn't useful, a progressively decimated buffer (along with images of entry and exit events) worked well.