I haven't tried to make an import script for 5e, but I did make one for 3.5.
https://app.roll20.net/forum/post/10672575/reviving-srd-importer-by-chris-s/?pageforid=10674542#post-10674542
As mentioned, the repeating sections might make it more difficult, but some of the stat entry can atill probably be automated quite easily. (ability scores for example) My 3.5 script would obviously not work for 5e since it uses the 3.5 attributes, unless the attributes happened to be the same which i doubt. However, the methodology could be used to alter the script.
Importing stats from an image sounds impossible. You would have to have a program convert it to text. But if it is text and there is a consistent format to how that text turns out when copy and pasted, it could be done.
Honestly, I never saw much need for this in 5e since the compendium takes out a lot of work. I developed the 3.5 script because 3.5 does not have a compendium.