Cutting images or not

[aazimon]

I just read a recent post, where they mentioned cutting a sprite image and then a response to use subImage() instead. It sounds like subimage may be a tiny bit slower. So which is better? Or does it not matter?
   If I plan to use Slick2D, does it matter with that?

[theagentd]

It should be "better" to keep the image as a single large image and just keep track of which parts of the large image are individual "sub-images", but in practice the difference is negligible. The only practical difference is the extra load time to split the image, but again, this too is negligible.

[ReBirth]

I didn't understand too, until I found libgdx need 2^n px sized image file