You may resize it using phtoshop ,
open the image > | + alt + command
or
Open the image > Image > image size > change it to the number u want.
If the pic is too small you may use some filters to resize it with high quality .
I hope I could help u .
NO.. this is what you need to do.. print out the image, then find a high quality scan[ner] and scan it in at like 900dpi or more if you can .. then you will be able to resize it easier..