XCF save file too big (error when saving)

[margimp]

Hello, I'm having trouble trying to save a "project" (xcf file) on GIMP. I get the following error: "could not seek in xcf file invalid argument". From what I managed to find online it may be because the save file size is over 2GB. I wanted to know if there are any workarounds for this issue and also know why is the XCF so big when my original image is a jpg file of only 130mb and I have barely added any features in it, just about 4 paths. The bottom part of the gimp window is showing "filename.jpg (7.9GB)" and I have no idea where did that 7.9GB came from since, like I said, I've opened a 130mb jpg image. I used to have a ~7.5GB filme with the same name as this one (higher res version) but I've deleted it already and opened gimp by right clicking the new file (130mb) and selecting "open with GIMP".

Thanks in advance.

[rich2005]

A 130 MB jpeg is a big file. What is the size of the image (width x height) in pixels. (shown at top of Gimp window).

The big GB value shown by Gimp is the jpeg image uncompressed + any layers + undo's etc.

If you give the Gimp version along with your computer specs, memory, amount of free disk space, someone might come up with some advice.

[Blighty]

In addition to the info asked for by Rich:

Go to Edit>Preferences>Environment
What is the 'Tile cache size'

[Ofnuts]

XCF is uncompressed while a JPEG is. There are lossless compressed XCF formats (.xcf.gz, .xcfgz, .xcfbz, see the filetype selector in the Image>Save file selector).

[rich2005]

A few tests for comparison:

Starting of with a jpeg 126 MB (98% quality) image size 10600 x 17000 pix -ish

Open in Gimp 1.8 GB, in memory. Duplicating layers to get to over 4 GB in Gimp and it does save as a Gimp xcf. File size = 1.28 GB

screenshot: https://i.imgur.com/TJ93PxK.jpg

Comment:
When saving as an xcf (and exporting as a jpeg) the save dialogue closed well before the image finished writing to disk. Do not assume the image is immediately saved and close down Gimp. Chances are you get a corrupt file.

AFAIK there is a 4 GB limit on Gimp 2.8 file size, although that must be a monster image. That limit is removed in Gimp 2.10

A test in Gimp 2.10 (2.9.9 in my linux machine) Added more to get 5 GB in memory. Saved in the new compression format which is not compatible with Gimp 2.8 It was slow writing to disk but the dialogue stayed open until the complete. This file size = 809 MB - a good saving in file size but did take 25 seconds to re-open.

screenshot: https://i.imgur.com/r3fZ2Tb.jpg

[margimp]

Thanks everyone for all the replies. As of today I got rid of that JPEG and got a less demanding (smaller) one since my pc was struggling when editing it in GIMP or working in GIS software. Its size was about 30.000 x 25.000 pixels, and I've got GIMP 2.8.22 running on an i5-3550, 8GB of DDR3 RAM and plenty of free space on a 5400RPM HDD.
Maybe my options would've been the higher compression save you did on the 2.1 version, Rich. I was impressed by the difference in size between the JPG and GIMP's xcf file, which sounded reasonable if I had opened the PNG or TIFF versions of the same image (about 1GB in size each), not a 130mb JPEG! But, I'm only a newbie in this field so thats one thing learned!