Oh this is a really cool approach! This has so much potential!!

Lets start with what I love:

The idea of “hashing” the resized images is so smart so we don’t need to recalculate and generate images on every build. Super cool!

+1 for Vips + Image Processing. Coming from Rails, those feel very natural.

The unexpected: I assumed “on demand image resizing” meant having multiple sizes, rather than only a single resize of an image.

I’m also not particularly in love with is adding the ERB helpers, I’d be quite interesting in using a post-build inspector to generate the image hashes and using the srcset attribute on <img> to utilize that which HTML already gives us, and have truly “dynamic” image sizes across device / viewport sizes! The added benefit being you can have multiple sizes, instead of a single resized image.

In my head, I picture doing something like this:

<img src="blah.jpg" data-sizes="thumbnail, 640x640, wallpaper"> or something silly like that.

Anyways, thank you so much for this post! So much to build off of here!

This is awesome! 🤘 I’m excited to play around with your approach.