[FFmpeg-user] denoise after scaling or before?

[Michael Koch]

Am 23.04.2019 um 11:43 schrieb Jon bae:
> Hello,
> I just have an general question:
>
> As I know denoiser are specialized to specific noise pattern.
>
> Makes it a different when I denoise after scaling a video, or is the
> quality better when I denoise before scaling.
>
> In terms of speed it would be better for me, denoising after scaling, but
> when the quality is better, then I would go that way.

You could try both versions simultaneously and compare them with hstack:

ffmpeg -i in.mov -i in.mov -filter_complex 
"[0]scale=640:400,atadenoise[a];[1]atadenoise,scale=640:400[b];[a][b]hstack" 
out.mov

There are at least six different denoisers available: atadenoise, bm3d, 
dctdnoiz, fftdenoiz, owdenoise and vaguedenoiser

Michael