Re: [gentoo-user] faded images with Gwenview

[Neil Bothwick]

On Tue, 14 Sep 2021 01:07:42 -0400, Philip Webb wrote:

> > Gwenview uses color-management via media-libs/lcms, feh does not.
> > See "Rendering intent" and "Color profile" under "Advanced"
> > in Gwenview's configure dialog.  HTH.
>
> That cb relevant, but I've explored further & have some results.
>
> When I crop a JPG image with Fotoxx or Gwenview,
> then view it with Gwenview, the colors remain vivid ;
> this is true whether I rename the new version in Gwenview or not.
>
> It's only when I crop a PNG image in Gwenview
> & save it in place (ie with the same name), that the colors are faded
> & that's only when viewed with Gwenview, not eg with Feh.
>
> So I can avoid the problem either by cropping only with Fotoxx
> or by renaming them whenever I do it with Gwenview
> or by converting PNGs to JPGs before cropping them.

The latter will result in loss of information.
 
> The bad case does look like a Gwenview bug,
> but KDE bugs tend to disappear into the ocean, if reported.
>
> Thanks for the comments.  I will try redoing the faded versions,
> tho' that will mean getting them from the I/net again.
> Any further suggestions re causes of the bad case are welcome.

It sounds like the images are fine, just that Gwenview is displaying with
the wrong colour information. The question then becomes, does Gwenview
save the colour information in the image file or separately. If you do
have another user set up, you could try cropping and saving as one user
and viewing as the other. If the second user sees the image as it should
be, it is the latter and you can locate and remove that information.

It does seems to be a bug, and one that has been around for some years:

https://forum.kde.org/viewtopic.php?f=66&t=139430


-- 
Neil Bothwick

And then Adam said, "What's a headache?