Rembg Virtual Greenscreen Edition (Dr. Tim Scarfe)

Rembg Virtual Greenscreen Edition is a tool to create a green screen matte for videos

  • Take any video file and convert it to an alpha matte to apply for a virtual green screen
  • It runs end-to-end non-interactively
  • You need ffmpeg installed and on your path
  • There is also a powershell script ./remove-bg.ps1 which will do the job in a manual way i.e. first create frames, then run the rembg -p ... command and then run ffmpeg to create the matte movie. This was my first approach to solve this problem but then I migrated onto just making a new version of rembg.

If you have any ideas for speeding this up further, please let us know. We have tried quite a few things at this stage and are a bit stuck on how to proceed from here. See some of the "evolution" in the Whimsical notes.


pip install rembg-greenscreen

greenscreen -g "path/video.mp4"

Experimental parallel green screen version;

greenscreen --parallelgreenscreen "path/video.mp4" --workernodes 3 --gpubatchsize 5

The command above will produce a video.matte.mp4 in the same folder, also works with mov and avi extensions. Uses ffmpeg under the hood to stream and re-encode the frames into a grayscale matte video.

Be careful with the default parameters, my 11GB GPU is already pretty much maxed with 3 instances of the NN with 5 image gpu batches in forward pass.

You can see how much free GPU ram you have with


CLI interface

Important notes

  • Don't use VBR videos, it will run forever -- use Handbrake to convert them to CFR