I’m rapidly approaching the finish line for John’s Background Switcher 2.5 and am getting quite pleased with what I’ve done. Progress had initially been slow as I just didn’t have enough free time to dedicate to it but lately I’ve been on a roll. One of the cool things I’ve just implemented is Mosaic mode. I’ve seen this feature around and decided to put it into JBS. In short, it lets you automatically create backgrounds on your PC using whatever search criteria you like from Flickr like this (which is interesting photos from the last 7 days):

Instead of downloading one photo and setting it as your background, it downloads a load of thumbnails from Flickr and builds up a mosaic image. Other implementations of this sort of functionality I’ve seen are pretty inefficient as they download one thumbnail at a time, thereby taking an eternity to build the picture. So I’ve spent a good bit of effort making it fast and smart to the point where it takes around 45 seconds to generate the picture you see above and makes as few calls to Flickr’s servers as possible.

It’s fun writing clever multithreaded, caching thumbnail downloading code, but it’s much more fun to use the resulting mosaic functionality to build up a picture of cat portraits or guinea pigs! In a couple of weeks you’ll be able to do it too!