I have taken a number of photos using my friend's digital camera and the default resolution is 640 x 480. However, when I try to send for printing, they say that the min. resolution for 4R is 1024x 768. My question is - is there a way to change the resolution of the pics from 640 x 480 to 1024x768 so that I can send them for printing? If so, what is the software to use?