I’ve found that when opening an openexr image with linear rec2020 color profile in krita, the colors are all wrong.
So I started investigating.
aparently Openexr does not embed a color space icc profile inside the image which is unlike other formats like jpeg or tiff that do embed icc profiles in the image file. openexr instead assumes a linear profile and stores the RGB primaries. From that the color profile can be reconstructed.
I’ve found that gimp and darktable seen to be able to do this and thus display the image correctly.
Krita aparently does not reconstruct the color profile from the RGB primaries. and just assumes sRGB-elle-V2-g10.icc
so far so good. then I just tell krita myself that the openexr image I opened is in linear Rec2020. I found this dialog:
and assumed that I can just select another profile and untick the checkbox for “Convert color space” to tell krita the image is in linear rec2020. But the color space gets converted to linear rec2020. I assumed it would just reinterpret the color space (is this a bug or a feature?)
Now I turned to OCIO. I turned it on and selected the aces_1.0.3 ocio config I downloaded. but which linear rec2020 profile do I chose now? and which viewing color space? I have found at least 4 that say linear rec2020 I’ve settled on the “lin_rec2020” profile. that seems about right but I’m still not quite sure if this is the correct one.
After turning on OCIO the openexr image (with the wrong profile detected by krita) and my reference tiff (with the correct linear rec2020 embedded profile used by krita) look the same. Good. but why do they look the same? their Profiles still don’t match, they shouldn’t look the same, or should they? I’m confused.
Does OCIO overwrite the image color space settings?
- Does OCIO overwrite the image color space settings?
- why does the colorspace still get converted even when unchecking the checkbox “Convert color space” under image/properties/colorspace
also some info on my system if that helps: I am using krita-5 with the “krita next” build on windows
I hope this is the right category for this questing. I am verry much a krita beginner but I know some stuff about color and image processing so I don’t think this is a beginners question.