[FFmpeg-user] denoise after scaling or before?

[Jon bae]

Am Di., 23. Apr. 2019 um 12:17 Uhr schrieb Paul B Mahol <onemda at gmail.com>:

> On 4/23/19, Michael Koch <astroelectronic at t-online.de> wrote:
> > 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
>
> You missed nlmeans.
>
>
Ok, thank you, comparing is a good idea too! In general I thought there
must be a more technically accurate way, but I guess this depends on the
selected filter.