Image Properties: "Print Size" in inches?

[Jack Parker]

When I open "Image Properties" the display shows the size in pixels and the resolution in pixels/inch (PPI)
But tells me the "Print Size" in mm !?
Is there a way to tell GIMP to show the size in inches?

The documentation says: 
"Print size
    Shows the size the image will have when it is printed, in the current units."

But I can't find documentation for how to set the "current units"

[rich2005]

Two instances,

1) Make a new image and the resolution is set in the Advanced Options (you need to expand it) see: figure 16.6 https://docs.gimp.org/2.10/en/gimp-file-new.html

2) An exiting png image and Image Properties.
This is an issue with png images and stems from the libpng that Gimp uses, so not really in the hands of the Gimp developers A clip from the bug report. https://gitlab.gnome.org/GNOME/gimp/-/issues/3360
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....Here's the problem line of code, which seems to be hard-coded to mm, instead of allowing a choice between inches and mm:
https://gitlab.gnome.org/GNOME/gimp/blob...ng.c#L1128
Edit: Hmm, libpng has odd choices built in - "PNG_RESOLUTION_UNKNOWN" which seems to mean "inches", or else maybe it means "whatever the user chose", with the only other choice being "millimeters":..
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If you want to see the value in pixels-per-inch then you can use Image -> Print Size and change the Resolution to pixels/inch. It does not affect the image in any way, only the information that the printer uses.

[Jack Parker]

Ok, thanks for the info/reference. That bug [sadly] matches my experience.

Even the bug report seems to get twisted between the file-info and the "GUI"
What we want is the ability to auto-flip the Image Properties GUI to "pixels/in".

Also: do you know where to edit the documentation?
Might be good to add something to explain this caveat...
(and clarify that "current units" for PNG is always mm)

[rich2005]

Quote:...Also: do you know where to edit the documentation?..

The place to ask is here: https://gitlab.gnome.org/GNOME/gimp-help/-/issues