Denoise videos where beamer or monitor projections take place
You might know the situation where you have to record someone presenting a topic (the typical PowerPoint presentation) and the projected material is being recorded with him.
The reason is that the emitted light frequency does not match well with the recording device. That creates a lot of noise as you can see here:
So how to tackle such problem? After experimenting with some filters in Kdenlive I discovered that the „Adaptive Temporal Averaging Denoise“ (atadenoise) filter does a nice job.
Here is the theory behind the filter:
For applying that filter I used Kdenlive which has become a nice software for editing videos. It is far from perfect, but good enough for my needs:
It uses the same parameters as ffmpeg which provides that filter as well. I guess Kdenlive works as its frontend here, not sure though.
The values for the filter I finally used for that video were:
av.0a = 0.292, av.0b = 0.730, av.1a = 0.286, av.1b = 0.520, av.2a = 0.286, av.2b = 0.435, av.s = 15
This is the result:
You might have to play around with the values if you want to denoise your video. It depends on what you have.
What do you think about this filter? Are there better ones? You are welcome to comment your thoughts. 🙂