ProPoster

Poster is maybe the easiest way to create a big poster from a high quality picture. The only thing you have to do is to select the size of the result image and ProPoster will automatically divide the image into several paper-sized parts. So you only have to print all the papers and once they are all printed, you only have to join them manually as if it was a puzzle. It lets you preview the result thanks to a magnificent glass which will let you know if the picture will show big pixels or not. It includes predefined sizes of papers like A3, A2, A1 or A0, but you can adjust them if the papers you use are different.