GNU license means what?

To keep a long story short, one of the major stumbling blocks that I had towards the end of my active solo development of my pet TC was a lack of suitable landing pictures- the planet desc text would talk about this or that main city or spaceport details, and shoehorning 'yet another terragen landscape lacking any urban features' into it was not a palatable result. My experiments with Mechanisto (the provider of nearly all of the rest of my graphics), albeit satisfying, took much more work to create per shot than I felt was practical.

However, I have amassed a significant collection of pictures that would make good landing shots from the Wiki, of all places. And the fact (as I check each one) that they have been released into the public doman/GNU licensed implies to me that I could use them for landing shots. Does anyone with any more wisdom than I have an ability to weigh in on this idea? Because I could spend a day cropping and adding some details (landing ships in the background, etc) and have my TC probably 30% closer to completion suddenly.

Since the images are easily extractable and you're not selling the mod, as far as I know, there'd be nothing wrong with it.

If it's public domain, then it may be used without restrictions.
If it's under the GPL it must be distributed under the GPL, so just add that to the readme and the about desc, and include a copy in the archive when you distribute it.

@rmx256, on Jun 12 2008, 10:11 PM, said in Picture Ethics:

However, I have amassed a significant collection of pictures that would make good landing shots from the Wiki, of all places. And the fact (as I check each one) that they have been released into the public doman/GNU licensed implies to me that I could use them for landing shots.

If they're in the public domain, you can use them without restriction.

If they're subject to the GNU Free Documentation Licence (which is the standard one for Wikipedia, and is not identical to the GNU General Public Licence), you can only use them subject to its conditions. These include crediting the original author, releasing your derivative work under the same licence, and reproducing the full text of the licence with your work.

Some Wikipedia images are also one of the Creative Commons licences, which have various conditions; you can usually find out what applies by clicking on the licensing link.

@mispeled, on Jun 12 2008, 10:38 PM, said in Picture Ethics:

Since the images are easily extractable and you're not selling the mod, as far as I know, there'd be nothing wrong with it.

Whether you're selling the end product is unlikely to affect anything, apart from how severe the penalties might be.

@david-arthur, on Jun 13 2008, 06:23 AM, said in Picture Ethics:

Whether you're selling the end product is unlikely to affect anything, apart from how severe the penalties might be.

Though I do think some of the public use licenses I've run across stipulate non-commercial use, which would of course change things.

@keldor-sarn, on Jun 13 2008, 05:51 PM, said in Picture Ethics:

Though I do think some of the public use licenses I've run across stipulate non-commercial use, which would of course change things.

There are indeed a number of licences which prohibit commercial use, but material subject to such conditions isn't accepted by Wikipedia, which I expect is the wiki to which the original poster refers.