Monday, December 9, 2013

Map sizes

I often grab pieces of maps from Bing and Google maps and use them to create specific maps (for example, plotting the locations of all Microsoft buildings). Today I was curious to see what would happen if you grabbed the entirety of Bing's maps and printed them out, so I did the math.

Bing maps' maximum available resolution is 10 CM per pixel, so if your screen is at a resolution of 1920x1080 pixel (minus the Bing toolbar and IE's toolbar), you can see an area of approximately 192 by 83 meters (576by 249 feet).

If you were to grab a picture of the entire US at that resolution, your resulting image file would be approximately 50,000,000 by 19,330,000 pixel. Using the common "megapixel" scheme of representing picture sizes, we're talking about approximately 966.5 Gigapixels! Naturally, no single computer would have enough memory to handle such a file, but if you could, and If you saved such a thing as a JPG with a medium compression level, the resulting file' size would be at least 40270833 MB (which are 40 TB). If you were to go and print this file at the standard high-quality print resolution (300 DPI), you would find yourself with a print that's 4234 by 1636 meters (2.6 by 1 miles).

Google maps, by the way, has about half that resolution, so the same output would be about a quarter - 241 GP image, 10 TB file, 1.3 by 0.5 mile print)

And finally, if you're interested in generating a JPG image from the maps, here is a guide to doing that. If that's not enough, here is a list of several other tools.