Y.H.Lai
September 19, 2022, 11:01pm
1
I posted this as a bug report before: 459415 – Krita exports weirdly huge pngs when colorspace conversion is involved (kde.org)
But I’m not so sure if it’s a bug at all or if I did something wrong.
For example, I opened this file in Krita, exported it as png with these options:
The result was 2.39MB.
Then I opened the exported file with Windows’ built-in Photos, and saved a copy with it. Now it’s only 767KB.
The 2.39MB file and 767KB file look the same to me.
What’s the hidden thing that Krita embedded in it? I checked “Force convert to sRGB”, so the exported png should have extra colorspace info, right?
Is it, by any chance, a 16-bit file?
Grum999
September 20, 2022, 5:51am
3
Hi
An example of PNG file, exported from Krita and the saved copy could help to understand the size difference…
Grum999
The linked .kra file is 16-bit integer RGB/A.
That file size difference could be explained by the Windows application saving as 8-bit RGB/A with a particular level of .png compression.
A similar .png size reduction can be obtained in krita by converting to 8-bit RGB/A and exporting with an alpha channel.
Y.H.Lai
September 20, 2022, 10:55am
5
Oh okay, you’re right. But there is no export option for the 16bit to 8bit conversion…
I know I can convert the colorspace for the whole .kra, but I don’t want it. I want to keep .kra in 16bit linear space and export .png in 8bit sRGB.
I filed a feature request here: An option to export 16bit .kra to 8bit .png - Develop / Feature Requests - Krita Artists (krita-artists.org)
2 Likes
Ralek
September 20, 2022, 11:45am
7
Yup, it’s been getting rather annoying saving as .png, opening the .png,changing bit depth, then re-saving as .png
system
Closed
September 23, 2022, 11:46am
8
This topic was automatically closed 3 days after the last reply. New replies are no longer allowed.