Adding Support for an Image Proxy (like Thumbor)

I have a catalog with thousands of high res image URLs and I would like to be able to generate a static site where they are included into the page using an imaging service like Thumbor. For those who aren’t familiar, Thumbor and similar servers let you specify a URL that takes a source image and then applies resizing, optimizations, and transformations onto it. So I might make a link that looks like{HMAC-SHA1}/300x200/, which would mean “take the image at and resize it to be 300x200 pixels”.

The signature has to be generated with a server side secret, to keep people from maliciously or accidentally pounding your proxy with a million different permutations. Ideally, it’d be great to be able to include the source image URL in front matter for a given piece of content and specify the resizing parameters in a Hugo template. I didn’t see any support for this in Hugo, so in practice I’ll probably end up generating a few different URLs in front matter instead.

My questions are:

  1. Does this functionality already exist in Hugo some place? This is my first time dabbling in it, so there’s clearly a lot I don’t know.
  2. Would it be a useful feature that the project would want?
  3. If it is a useful feature, where would I start in terms of adding it in the code? Are particular examples that would be good starting places?

Thank you!