Celestia Forums

I'm trying to tackle a recoloration of the Blue Marble textures in 16k,
but have been unable to find any program capable of scaling the
native 21k x 21k hemispheres down to 16k in Windows XP, using my 512 kb of memory. GIMP can load, but barfs during the scaling operation. The Win32 compiled ImageMagick utilities, even when I enforce memory/map limits, simply hang accessing the disk continuously for 8+ hours. I can't
even get them to simply crop.

I know there are possibly some linux utilities that could tackle this under Cygwin, but I'm only aware of the pamdice (etc) ones, and not any utility that can convert .jpg (or preferably, interleaved RGB raw) files to the net pnm format.

Does anybody have any suggestions?

Photoshop CS can deal with images up to 300k * 300k, but I don't know about netPNM support...

Or if you can locate and older version of Photshop 5 or 6 that will let you do it. I am sure if you look you might find a copy of these older versions somewhere at a good price. Also try adjusting the tile cache size in GIMP. That should help. I was able to work with a 16k texture with 512MB of RAM so you should be able to do it as well. Another thing to do is you are using Windows 2000 or XP you can manually adjust the size of your virtual memory partitions . This will also help to get big textures loaded. If you have a big hard drive or a second hard drive you can I believe set the maximum size of your virtual memory to 2048MB with 512MB of RAM. You can set your main virtual memory partition to that size and if you have a second hard drive with the space needed than you can add another virtual memory partition. This will give you just over 4Gigs of virtual memory. Photoshop loves big virtual memory partitions as does GIMP.
If you don't know how to set them than just ask in here and I will give step by step instructions.
Also you could just spring the money for more RAM. RAM is pretty cheap. Even buying a mere 256MB stick should be good enough to get you going.
I hope this helps.

Don. Edwards

sombrehombre wrote:I know there are possibly some linux utilities that could tackle this under Cygwin, but I'm only aware of the pamdice (etc) ones, and not any utility that can convert .jpg (or preferably, interleaved RGB raw) files to the net pnm format.

netpbm (i.e. the "pamdice ones") comes with many converters, including jpegtopnm, rawtoppm etc., and of course pnmscale, so all you need is diskspace.
You can also do some image manipulation (like color correction - ppmbrigten) with netpbm.
http://netpbm.sourceforge.net/doc/directory.html

Harald

It turns out that even the Win32 compiled version of the NetPNM utility library can handle the task with no problem...

Of some interest - a 42k Earth cloudmap is possible from these source material, using Don Edwards discovery of static clouds.