How can I change a picture to make it have better quality?

I'm not talking about a picture you take from your camera, I mean an image you get off the internet.How can I change a picture to make it have better quality?
If you mean %26quot;higher resolution%26quot;, you can't do that easily. For higher quality you can approach it the way any good artist would approach it. There are various tools in the gimp software that I have used to improve product photos that were emailed to me. Airbrush and pixel editor are some examples. For more information about the free open source Gimp program visit http://www.gimp.org/How can I change a picture to make it have better quality?
I really don't think you can. You'll need the original to make it better. Sometimes with photoshop you can fake it a bit, but you'll need to research ways to do that. Google 'retouch photo' or something similar. Good luck!How can I change a picture to make it have better quality?
convert the file into a png file as opposed to a jpg file.How can I change a picture to make it have better quality?
Cant. Pictures from internet aren't vector based. internet is bitmap.



look here

http://en.wikipedia.org/wiki/Vector_graphics