'Save Thumbnail' causing 16-bit PNG export taking a very long time - Gimp 64 2.10 on Windows 10 x64
GIMP version: 2.10
Operating System: Windows 10 x64
Package: [flatpak? Installer from gimp.org? If another installer, tell us where from] Partha's Place build
Description of the bug
WHen I export 16-bit PNGs of anything larger than 24mp (6000x4000) which is my camera (80D)s resolution. The export window takes a long time to close (usually between 3 - 10 minutes). I do a lot of panorama stitches that end up being approx 150-200MB 16 bit png when finally exported. What's strange is that usually within about 10 seconds of the progress bar being finished (which usually only takes about 20 seconds to complete at most, the file is actually written to the export folder it is being written to, and if I open it it seems completely fine/complete, even though the export window will still be 'on top' of GIMP for sometimes even 10 minutes or slightly more. I don't think it's an I/O issue as I'm writing to an internal HD in a desktop PC.
Changing compression amount at export does not seem to make a difference. Also it would not appear to be a CPU issue, as even B&W images take the same amount of time.
Is the bug reproducible? [Always / Randomly / Happened only once ]
Always
Reproduction steps:
- Open an image in Gimp which is larger than 6000x4000
- Export as 16-bit png.
…
Expected result: Export window closes shortly after progress bar completes
Actual result: Export window stays there for a long time
Additional information
System:
i7 3.8Ghz 24GB RAM Windows 10 x64 GTX 1080