Targa exporting omits transparency data in the background if layers are larger than the canvas
Operating System: Windows 10 (64-bit)
GIMP Version: GIMP v2.10.32 (Revision 1)
Description:
The title pretty much speaks for itself, whenever you perform an image format conversion of any type into Targa (TGA), all transparent colors in the background gets erased and replaced with a solid background color according to whatever color you have set, this also occurs whenever you crop images in a different format or in an already existing Targa image after exporting the changes.
This isn't a bad thing under the right circumstances, the bigger issue is the fact the software automatically does this with absolutely no options that allow you to preserve or omit that information. I tested with Paint.NET and by default the transparent color data in the background is automatically preserved if any exists for said image(s), funnily enough that software suffers from the opposite issue, you can't omit the transparent color data in the background but you can automatically preserve the existing color data in the background with no options to say otherwise.
GIMP would benefit with an extra option for preserving or omitting the transparent colors in the background. In more basic terms, if you disable visibility of the alpha channel and you notice extra bits of colored pixel data in the background of the image (mostly occurs when you delete pixel information in the foreground), that's the information that should be given an option to preserve or omit. Some pieces of software utilize both the foreground and the transparent color data in the background to make up texture elements and such, hence the importance of this issue.