Too saturated colors at fit to view (screen)?

Hi, recently I edited some photos of the woods with lots of saturated greens. However, I have noticed that the saturation appears to be stronger if I view a photo at fit to view. When I export the photo to jpeg (sRGB) and view it with a (color managed) image viewer, the colors are less saturated. However, if I zoom to 100%, saturation is the same both in RT and the image viewer (in this case Eye of Mate).
I am using RT 5.6 Appimage on Debian 10 on a dual core Intel laptop with 16 GB RAM. Screen is a wide gamut BenQ, hardware calibrated and profiled. Profile was set with dispwin. Profile type is XYZ lut + matrix I think.
To me this looks like a bug but I am using RT since a while and I never noticed this until now.
Also uploading some screenshots, the original RAW and the sidecar file so maybe someone can check or reproduce this.





P7200086.ORF (15.1 MB)

Creative Commons License


This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
P7200086.jpg.out.pp3 (12.1 KB)

Thanks in advance and regards
b

Have you tried using the colour inspector? Do the colours change? If not then it is just an appearance phenomenon where proximity and rounding may affect our perception. Sometimes, I use a separate colour picker app on top of the canvas(?) to verify whether it is a colour management issue.

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Apparently the color does change if I zoom in and out:

However, I do not really care what the reason is. Zoomed out view does not look correct.

Maybe it has to do with how RT shows raw images? That is, the preview onscreen is not the real raw image, as explained in Rawpedia. Perhaps those saturated colors are not well resolved while zoomed out.

There’s too a feature request at Github asking a preview as real as possible.

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The colors measured by the pipette tool depends on the zoom factor: when zoomed out, the sampled area used to calculated the average RGB is larger than when zoomed in.
However for the visually perceived color difference, I have no idea.

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When did Eye of Mate get color managed? I’d double check that.

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EOM is definitely color managed though it does not like all profiles. I have opened the photo in several other color managed viewers and editors, it looks the same as in EOM.

W10, last dev build, viewer XnviewMP

@betazoid

  • I made 2 sceenshots of your photo in RT: one with 200% zoom and one with 16% zoom
  • examining the RGB values for the same location in viewer This location is saturated at 200% zoom and is not at 16%.

I identify two possibilities:

  • some processings (denoising…) can only be viewed at 100% and above and could modify the RGB values. I would like this threshold be user defined.

  • In order to view the image at 16% in RT (generally under 100%), there is somewhere a resizing. This resizing could be rudimentary (e.g. linear) thus spoiling the view. A resizing in the viewer gives a very different image.

edit:
I am going to compare a screenshot from fit to screen RT window with generated jpg but I have a problem with screencapture color management

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I am not sure if I understand the technical details, but I have checked this with several other photos and apparently the issue only exists with lots of very saturated greens.
Anyway, I want to stress that I am using RT regularly since about 18 months now and I have not noticed this until now. Well I am using RT with a wide gamut screen since a few months, afik it is above all the greens that are very different in larger color spaces. I guess I will do more tests with different profile types. Maybe it is the profile type that RT fit to view/screen does not like?

Too hot here in Paris to test RT :nauseated_face:

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Having just gone through several weeks of heat I agree. :sunny:

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I’d investigate the monitor profile – some colour-managed applications don’t seem to like LUT+matrix monitor profiles, so I’d create a single curve MTX profile in DisplayCal and see if RT behaves better with that. You could run the DisplayCal tests in your colour-managed apps to investigate the issue with some reference files.

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You need to Assign your monitor profile to the screenshot file, and then Convert it to sRGB in order to share it online.

I just tested it with a single cure+mtx profile and it is still the same, colors (greens) too saturated in fit to view preview.