/3/ - 3DCG

Okay.... this program is old, but still popular among the few who use it to enlarge images to very high resolutions, even I have used this prog for silkscreening...
http://pirateuropa.net/ulead-photo-express-6-0-tf1715061.html
...I'm probably not allowed to post torrent links here, so I'd better read the site rules right now. Meanwhile grab this program while it's still posted here. Hope this will help you achieve high quality textures for your model.

(that Mazinger head is just my avatar... nothing to do with the help I explained above.)

Try making a high resolution size of that image. That's what I do when I use image textures for 3D objects. Programs such as Irfanview will help. But if you wanna make a really high definition image (resolution sizes 2000x and up) try a photo editing program such as Inkscape or Ulead Photo Impression. I want to help further with this, but I'm in the middle of a task at a another computer right now. I'll bookmark this page and come back to it later. This is my first visit to 4chan, by the way.