Here is a further explanation about the three different modes in Blow Up 3.
Blow Up enables you to enlarge images to huge sizes without sacrificing image quality. It makes it easy to make photos big enough to print on a semi truck or a billboard. This video shows you the basics.
This is a brief introduction to Blow Up 3. You'll hear and see what the program does and what it's capable of doing. To learn more about Blow Up 3, watch the Getting Started video.