Peppers under ettr test

I like your “shadowy” look… :slight_smile:

just for fun


DSC06043_01.ARW.xmp (6,6 KB)

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:slightly_smiling_face:

La melanzana è fantastica!

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If anyone is interested in testing i’ve uploaded two versions of the same file, 06040 (10 pixels clipped), 06039 (no clipping at all).

Exposure set and then exported from darktable as unbounded, 32-bit linear TIF. I did not touch contrast, so it is low. There was some compression applied to highlights; colours were mapped to sRGB. Both tone compression and gamut compression were done in OkLAB, using my toy project.

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@priort , I think I understand relative.col vs. perceptual output and indeed I generally use a profile that support perceptual, the “ICC Preference perceptual” which I’ve mentioned previously. It’s the jiggery pokery in DT I don’t get at present, need to invest some time.

Here are the peppers using @jorismak 's XMP with sRGB websafe and then the pref. percep one. I think the latter looks rather better.

According to Aurelien perceptual and relative intents don’t work in DT… I think you need lut based profiles for these to work but I am not sure… I just presented that diagram to emphasize the gamut being displayed by the two different indicators in DT…

EDIT:

I was on my phone before but I can see the difference now on my PC so something appears to be working here by choosing different intents…

EDIT2…

I can’t replicate what you were able to produce

With my xmp or the one you used and all combinations of settings LittleCMS off or on… setting intent with output profile and leaving export to image settings or at the export or setting both the to match I get the identical image with no observable difference between relative and perceptual. I wonder what others would see trying the same…

Edit3

Looking at the exif data my jpg are both rendered as perceptual despite having different settings applied… I wonder if my OS is doing something here…

But looking back I think I am seeing what others have so maybe I misunderstand what profiles you are using because I dont think the websafe one in DT will support intents… Colour management - intents

Just saw this thread today. Here’s my take-

  • The pepper needed some TLC.- two instances of color balance RGB to color grade two different casts in the bright areas at the top.
  • Toned down the background and left/right sides a bit. Not a vignette, but just to subtly move attention to subject.
  • Modified filmic v6 used, with 0.35 threshold on highlight reconstruction.
  • Guided Laplacian to tame the reflections on the pepper a tiny bit, though it is barely noticeable.
  • Tone equalizer to bring down some overly bright highlights.
  • Blur using diffuse/sharpen “simulate watercolor” in subtract blend mode to bring out some surface details. Then add a small exposure boost to bring the luminance back to the original level.
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Are you sure nothing changed between edits there?
I load jorismak xmp and export three versions:

  1. Output Profile: srgb websafe. Export Profile: Image Settings, relative intent.
  2. Output Profile: srgb2014 (v2 perceptual). Export Profile: Image Settings, perceptual intent.
  3. Output Profile: srgb v4 preference (perceptual). Export Profile: Image settings, perceptual intent.

Profiles for 2 & 3 taken from sRGB profiles

What I see for this image is that all 3 look identical when viewed in krita (3 looks slightly different to 1 and 2 in geeqie and firefox, perhaps because those apps don’t handle v4 properly?) . None of them look like your perceptual output.

I continued this part of the discussion here…

@Soupy , nothing changed in my XMPs (except output profile)! Presumably you said to use little CMS in DT settings? And perhaps check you put them in the right folder. sRGB_v4_ICC_preference.icc is the right one from the page you linked to. Have a look at your Terminal log, I get an error message using this profile, “unsupported profile” or something like that. If you don’t get that, you are probably not using it for some reason, wrong folder I’d imagine. AurelianP once said something about this, I think the message arises because the profile is incompatible with parts of DT but nevertheless goes thru to LCMS ok.

I am getting that error message.

[dt_ioppr_set_pipe_output_profile_info] unsupported output profile 0 /home/usr/.config/darktable/color/out/sRGB_v4_ICC_preference.icc, it will be replaced with sRGB

Which folder do I move the profile to avoid the error? Or which setting do I change?

Have tried with LCMS2 on and off.

Don’t worry about that message. It will be applied as the output profile. See here:

[the error message] just tells that darktable won’t be able to use profile internally for some things […]
However, the output color profile module will apply the requested color profile and intent (using Little CMS 2) at export.

I don’t know if it matters , but i had a sRGB icc file selected in the output profile module i guess.

I use Elle’s v4 profiles and export to linear (g1). Do my downsizing in an external app and that converts to regular sRGB trc.

That’s also where i export to rec2020 linear , with Elle’s profiles … but since filmic can’t give a good preview of the rec2020 output , i try sRGB more these days.

(Still frustrated by the lack of filmic softproofing… might actually dive into the code myself ).

Thanks @kofa
I tried again with both v2 and v4 perceptual profiles, compared to websafe.
I made sure to compress history before each export (in case that affected filmic gamut mapping, not sure).
v4 perceptual was identical with lcms2 on or off.
v4 perceptual was very similar to websafe relative, but noticeably different.
v2 perceptual was near identical with lcms2 on or off, difference hardly noticeable.
v2 perceptual was near identical to websafe relative, difference hardly noticeable.

This shows that the different profiles, intents and lcms2 settings are actually doing something, which is good. However, none of it looked like the perceptual result @RawConvert posted above, so I’ve no idea how he achieved that.

I do too, but want to compare / fine tune with perceptual profiles.

I think I see the confusion. I always have output profile/output intent set to Perceptual. I didn’t notice that jorismak’s had relative colorimetric set. This is what makes the difference in this example. So take jorismak and just switch between the two profiles (websafe, preference perceptual) and you will hopefully get the same results as me.

With intent set to Perceptual, I’m seeing no difference between the two output profiles. I switched from filmic to sigmoid for this in case filmic gamut mapping was playing a part. The lack of difference is perplexing but I haven’t time to get back into this at the moment and review what was said previously.

Is there a difference between Rel.Col. and Percep intents with the preference profile? Yes.

Yes I can confirm that too. Output Profile intent set to relative and profile v4 preference, Export Profile set to image settings, I now produce your results.

This is very counter intuitive, since the whole purpose of the v4 preference profile is to use the perceptual intent. It feels like a mistake.

And because I’m bored and green bell peppers taste better then yellow ones:

RAW to tiff with RawTherapee, rest was done with Krita.

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I’m sorry, but lighting in this shot is not good and you will struggle to get something pleasant out of any tonemapper. That being said, I prefer sigmoid in just about every time. Perhaps you need to explain what you’re testing, I’m familiar with exposing to the right.

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