Consider using Intersection Observer API?

[henrylearn2rock]

Intersection Observer API
https://developer.mozilla.org/en-US/docs/Web/API/Intersection_Observer_API

Polyfill from w3c
https://github.com/w3c/IntersectionObserver/tree/master/polyfill

Recommended from Google Chrome
https://developers.google.com/web/fundamentals/performance/lazy-loading-guidance/images-and-video/#inline_images

This api is well suited for this awesome project.

It'd be even more awesome if you can also mention how yours is different in comparison to these:
https://developers.google.com/web/fundamentals/performance/lazy-loading-guidance/images-and-video/#lazy_loading_libraries