Yeah it's a little app called, wait for it.... rasterbater!
Basically, the view is from our balcony in Tuscany where we got married this year. I wanted a HUUUUUGE vista on my wall so found this little tool. You can load in any pic, set the max amount of A4 sheets you wanna use, and it prints out each image for you. The images are made up of coloured dots (like a newspaper photo) and you can edit the size of dots to use, so if you had a simple image, you could use big dots.
I just did a little test to see how it would look - there's an option to print to the edge of the page so I can get rid of the borders and make it look like one whole image, rather than one made up of many images.
Ultimately I want to print out on decent photo paper. It's gonna cost a bit in ink, but it's cheaper than going to a reprographics company and getting them to do a one off.