[Suggestion] Lens correction filter proposal

[Eneen (Alex)]

Hi,

I would like to propose/suggest to add lens correction plugin based on
lensfun library. Currently lensfun includes converter from
Adobe profiles too so is extremely versatile. Software that would most
probably benefit:

• Krita - doesn’t have any lens correction
• photoflow - has experimental, incomplete feature
• flowblade - not sure if build in lens correction is profile based
• GIMP - would benefit a little as there is working GimpLensfun plugin
  but is experimental on windows

G’MIC already has lots of photo post-production filters like denoisers
and color graders so that kind of plugin would perfectly fit - all in
one place.
I’m not developer myself but I wanted to share idea.

Best regards.

[patdavid]

I think that @Carmelo_DrRaw is already working on LensFun integration for PhotoFlow…

Need sample RAW image taken with a lens fully supported by LensFun

I would like to complete the LensFun integration in photoflow, adding vignetting and CA correction. However, none of my lenses is fully supported by LensFun, hence i have no RAW sample to check the results. Does anyone happen to have a wide-angle lens, with visible distortion/vignetting/CA, and which is fully supported by LensFun? If yes, would it be possible to have a sample RAW file that I could use to test the lens corrections (ideally some architectural shot with straight lines or somethin…

[Eneen (Alex)]

Indeed, but idea was to add this filter to G’MIC so all apps would benefit.
I’ve also found, that g’mic is on kdenlive roadmap: https://kdenlive.org/2016/08/kdenlive-16-08-0-is-here/ so one more app.

[patdavid]

I’m sorry - I don’t know why I thought PhotoFlow was relevant to your question about G’MIC. I blame not enough coffee!

[Eneen (Alex)]

It’s been relevant! Photoflow uses g’mic so there had been chance that dev would put code into g’mic and many apps would benefit - one great filter for all.

But as Photoflow dev said:

@Carmelo_DrRaw

the vignetting correction requires RGB data in linear encoding, so it is best applied on the linear RGB data in the camera colorspace, and before the conversion to the working colorspace

So raw converters need their own lens correction.
I’m not sure here why, but maybe g’mic in photoflow stacks after gamma and camera response so even though g’mic is able to work in linear space it doesn’t have access to linear data.