(04-23-2023, 08:59 AM)david Wrote: I have tried with a .TIF file of the same size which I had successfully processed in the past, using the same procedure.
This showed the same problem. I re-instated my original profile and the result was the same. This suggests to me that there is no problem with the profile.
Running Gimp from the terminal does not give any error message.
Suggests to me there is something up with the tif file when opened in Gimp. Can you give a clue as to origin of the tif or some details on size in pixels, colour profile, anything.
Imagemagick with the command identify -verbose filename.tif is useful.
Do you still have an old Gimp 2.10.22 appimage available ? You could try that.
EDIT: I just pulled out the largest tif I have, 144 MB / LZW compression / sRGB - Opens in Gimp 8032 x 6622 pix, with a layermask and a selection saved as channel Shows in Gimp as 873 MB Selections / colour invert working OK.
So I wonder what is going on. Looking at my synaptic log, there was a libtiff5 update last month, I have this: libtiff5 4.1.0+git191117-2ubuntu0.20.04.8
Is everything up-to-date ? Just a thought. Although you have no problem with smaller files, so maybe not that.
What are you using to convert the .NEF file to tif ?