I have a video which I need to analyse. The analysis software recognizes objects outside the area of interest and I would like to limit it to the specific arena. In order to do so I tried cropping but unfortunately my arena isn't rectangular. I thought about blackening parts of the video. But how will I be able to do so? I'm a technical person but I don't have any experience in video editing and I'm also working on a low budget.

Does anyone have any idea how to solve this problem?

Best regards,


1 Answer 1


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 "subtractive" 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 :)

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