Selecting specific part of a video
You haven't specified which program you are using, but assuming that you have access to After-Effects or any Node- or Layer-Based compositing-program, you would want to rotoscope the area, that confuses your analysis. This is the same principle as using a camera-tracker, but subtracting moving areas or people in your footage. To do so, you would simply have to import your footage in, say, after-effects, grab the pen-tool, mask out the undesired area, set the mask so &quot;subtractive&quot; and render out the video again, preferably in prores4444 or any other (near) lossless codec and container.
I hope this helped, have a good day :)