Likely this will not be an open source thing, but I want to mention this service anyway for those you using #screenreader software and have related #a11y #accessibility needs.

Project Naptha looks to be a service that can generate descriptive texts for any image.

https://projectnaptha.com/

It is discussed on Hacker News now at:

https://news.ycombinator.com/item?id=32051736