Our video CDN customers can use a custom URL to get a thumbnail of any size from any key frame in their video files, fantastic for building "trick play" responsive HTML5 video player UIs without having to manage a single image.

Just one of the countless little nice-to-haves that sets a VDN apart from a CDN.

protip: Dynamically generating content by URLs is also a nice DOS attack surface if you don't rate limit in some way or try to detect abuse.

If you're using a CDN, just make sure they cache on query string parameters. Our resize controls were part of the URI, but the other commands were part of the QS. Our CDN stripped queries, so the first image would be cached and any calls with different QS would return the first hit.

A possible alternative that I never implemented was using the request header instead of the query string for additional commands.

Edit to add: Also, if you have lots of resized images on a page, be careful when Google or Bing scraped you. Your CPU and IO will go through the roof as your servers go crazy trying to dynamically generate all the images.

I wrote https://bitbucket.org/btubbs/thumpy at work and we've been using it in production for a couple years. It's very similar to Pilbox.

Wouldn't it be easier/quicker to either:

a) Have a command-line tool to resize images? Alternatively, one that's integrated into the shell so that you can access it from context menus? I.e. right-click -> "resize image"

b) Just open it in mspaint or your open-source image editor of choice?