Bit of a head scratcher. Exporting a processed raw as jpeg is fine. Export the same file as a tiff and it looses all contrast and gains a bump in brightness.
Tried various iterations of settings to no avail.
Anyone experience similar?
Anyone offer a solution?
Please and thank you.
jpeg v tiff
export as jpeg
export as tiff
Very few viewers know how to show floating point TIFFs correctly. Most just skip applying the colour profile, or blindly apply one that doesn’t match.
Change pixel type to unsigned integer and let us know if that resolves your issue. I use floating point when I export as an xcf file to open in GIMP for further editing.
Floating point TIFF gave me the same issue, I agree that is probably the issue. On a side note, if I understand correctly, high quality resampling might not give you the same colours on export, I never enable it.
Floating-point TIFF is encoded in linear (without a ‘gamma’, or with ‘gamma = 1’). Unless your viewer can handle that before sending it to the display, it will look washed out. (this answer was plain wrong, see very low contrast tiff on export - #7 by kmilos)
If you downsample it may produce results closer to what you see in the darkroom (which is also downsampled early, at the beginning of the pipeline, to save on processing).
With the option off, your colours / contrasts may vary depending on the output resolution (modules involving non-pixel-wise operations, such as sharpening and blur operations are the ones where the difference will be significant, with the haze removal module being the worst offender).
With the option on, the output will match the darkroom, if you also enable high-quality processing there.
Note: progress has been made on resizing affecting the modules, for example Haze removal work (again) by jenshannoschwalm · Pull Request #18632 · darktable-org/darktable · GitHub
Not necessarily. dt encodes it in whatever colour space you tell it to in the export settings, regardless of the pixel format. In principle, it does nothing wrong, and you can import it back to dt without issues.
It is that most viewers assume it is linear when they see float and disregard the embedded profile. That’s why it comes out lighter - they blindly apply a second sRGB gamma on top of whatever transfer curve was there.
Yes, sorry, you are completely right. It’s only that I ever use floating point output with linear files. Thanks for correcting me.
Ahhh, I see. What would the general advice be if downsampling on export, which I almost always do. Leave it enabled, and enable it in the darkroom before exporting as a final check?
Exactly.
SOLVED
That resolved the issue. Thanks for keeping me right.
For fun, you can also try exporting to float, but w/ a linear Rec709 profile.
yup, that works too. Ta very much
