GIMP crashing systematically with large files

[deadshade]

I have a really crippling problem (2.8 user)
I am working on a large topographic file which is 22 000 x 22 000 . Gimp is saying 4 GO and some when I load it . My RAM is 32 GO .
Now what I need is to isolate a part of this picture (about 5 000 x 3000) .
Whatever I try (cutting off , doing a transparent or white selection) when I want to save the result , GIMP crashes to desktop with no error message .

I will not be able to finish my work if I cannot get this small 5000x300 part what makes me desperate .
Can anybody here help me with explaining what is happening (I have obviously more than enough RAM so why would GIMP want to crash ?) and how I could solve the problem ?
Many thanks in advance .

[rich2005]

Going to be a problem diagnosing that crash I think.

This a similar sized image in Gimp 2.8.22 - linux and a select - copy - paste-as-new-image works. Although using some of the swap partition which never happens. I have a lot less resources than you. Screenshot: https://i.imgur.com/garOvuc.jpg

You could try increasing the tile cache size : https://i.imgur.com/8GwHTRo.jpg

Do you have plenty free disk space and are you using a fixed disk? Not some usb attached.

Possible work around: Do you know where the 5000x3000 area is? Could you split up the image into quarters using ImageMagick command line? Then work on a smaller image.

[deadshade]

Thanks that's a lot of things to try .Yes , I have plenty of disk space , yes I use a fixed disk and no I have no USB attached .
Yes I know exactly where the 5 000 x 3 000 area is . It is actually the purpose of the whole process - I need to get this area in order to merge it to another map where this area is not complete .
Actually I have 2 large 22 000 x 20 000 files and I need to merge a part of the first with a very small portion of the second . What is the "ImageMagick" and where can I find it ?

[rich2005]

(10-05-2018, 11:29 AM)deadshade Wrote:  What is the "ImageMagick" and where can I find it ?

Get a Windows installer from https://www.imagemagick.org/script/download.php down towards the bottom of the page.

It is command line. The command to split into 4 is

Code:

magick map.png -crop 2x2@ out_%02d.png

For comparison: The map.png 22000x22000 px is 307 MB on disk
took 2'30" to split into 4 11000x11000 px png's  and a lot of cpu activity.

[deadshade]

OK so I installed the Magicks and copied your line substituting to map.png the name of my file . As expected it didn't work because it apparently wanted the adress of the file with all the C:\ etc .
When I figured it out and found out how to write the adress , I got a message : 
Permission denied @ error/blob.c/OpenBlob/3489. magick.exe: no decode delegate for this image format `' @ error/constitute.c/ReadImage/556.
No idea what it means and so I am stuck .

Edit : OK now it worked or at least there was no error message and teh computer was apparently doing something . However I expected that the result will be 4 smaller images but I can't find them . They are not where the original picture was and doing the search on the name gave nothing . Where can I find the 4 images ?

[rich2005]

Quote: However I expected that the result will be 4 smaller images but I can't find them . They are not where the original picture was and doing the search on the name gave nothing . Where can I find the 4 images ?

You find them wherever you started the terminal.

The obvious is make a project folder, put the big images there, run the ImageMagick (IM) command from there and everything will be in that project folder.

However as a Windows example in a Win7 virtual machine, with very limited resources, 2 GB memory, small drive,

Putting the map.png on the desktop and running the terminal from there, (set the colours so you can see it), eventualy comes up with the four out_xx.png files. You do not have to use png. jpeg, tiff will work. Just do not use .xcf, IM can read but not too good at writing.

[deadshade]

Sorry I don't understand "You find them wherever you started the terminal." because I find them nowhere .
I don't choose where I "start the terminal" . I simply select Windows PowerShell (it's where the commands are in W10) . It apparently "puts" me in C:\users\Tom (e.g the input line starts with C:\users\Tom>)
Then I exactly copy the command you gave by substituting to your map.png the right adress of the file I want to cut (C:\users\Tom\Desktop\Hrestopography.png) and hit enter .
The computer starts doing something and when it stops whatever it was doing , there are no new 4 files on the desktop . Nor elsewhere for that matter .

[rich2005]

(10-05-2018, 04:46 PM)deadshade Wrote: Sorry I don't understand "You find them wherever you started the terminal." because I find them nowhere .
I don't choose where I "start the terminal" . I simply select Windows PowerShell (it's where the commands are in W10) . It apparently "puts" me in C:\users\Tom (e.g the input line starts with C:\users\Tom>)
Then I exactly copy the command you gave by substituting to your map.png the right adress of the file I want to cut (C:\users\Tom\Desktop\Hrestopography.png) and hit enter .
The computer starts doing something and when it stops whatever it was doing , there are no new 4 files on the desktop . Nor elsewhere for that matter .

Well, maybe do not use powershell. see: screenshots https://i.imgur.com/cKER37F.jpg

In Windows explorer, type in cmd (1)
That gets you a terminal in C:\Users\..yourname.. (2)
Run the IM command with the path to the map image. (3)

I put in some timers too see how long to render in a Win 10 (VM) with 3 GB memory and very little free disk space.
Might have missed the correct end, since I was cooking food. (should be less than that even for Windoze)
As an example changed the out format to jpeg. The file name can also be changed to whatever you want just keep the %02d.  for the numbering. All sorts of things you can do with IM.

best of luck. From your original report I think I might be checking the computer hardware.

[deadshade]

Problem apparently solved .
I decided to make the big jump and installed 2.10.6 . The crashes disappeared for the time being .
So , clearly , there was something in 2.8 what had a problem with large files (or with its interface to Windows) and we'll never know what it was .
Btw my computer is rather top end recent hardware so that the crashes can't be related to CPU power , graphic chip power and memory , RAM or disk space I have many Gigas of all that available .

The strange part is that GIMP simply and immediately crashed to desktop as soon as I clicked on "save file" with no error message from GIMP or Windows .
Thanks for the kind help .