Darktables export looks different to what darktable shows

Hi all,

I used darktable to reduce noise of a high ISO image. When I export that image as JPG (Quality 100), view it at 100% and compare the result to the image shown in darktable at 100% I can see that the exported JPG is not as soft as shown in darktable, but noisier/grainier.

You can see it in the screenshot I made, for example the structure of the white lines (on the left side you can see darktable and on the right the exported JPG).

Unfortunately I cannot share the whole image or raw file :confused:

When loading the exported JPG back in darktable I can see those noise/grain in darktable, too. So it does not seem to be related to the image viewer.

What can be the issue here?

Some notes:

  • I export at the same size as the original RAW file.
  • I use AMaZE as demosaic.
  • I tried different export formats using different bit depth.
  • The gamut check mode does not show anything, at least not in the mentioned white lines (see screenshot).

Best regards,

what denoising are you using? with what settings?
can you try other demosaic algos? (for me AMaZE works weird with high-iso)

I also tried the other two demosaic algos (PPG, VNG). The results are similar.

I use two “denoise (profiled)” instances.
One using chroma preset (wavelets auto) and manually set profile to “DSC-RX100M5A iso 1600”.
The other one using defaults (e.g. non-local-means), but again, I set the profile as above and increased the patch size to 7.

Disable high-quality export.

You mean setting “high quality resampling” to “no” inside the export panel?
That does not make a difference. Both, “yes” and “no” produce the more noisier JPG.