Plugin - auto image resize on upload, code review + help to package as an Extra

Today I found a Plugin I forgot I'd put together. It automatically resizes images that are uploaded and are outwith set dimensions. I wanted this is to prevent clients unnecessarily overusing server disk space by uploading tens of 8mb images straight out their camera when a 100kb image is plenty.

Question #1 - does anything like this already exist in the Extras repository? I checked months ago and took a quick look again today but don't see anything. Or maybe Bob Ray or Susan has written an article covering this?

Question #2 - if the answer to #1 is no, is anyone interested in reviewing the code with a view to identifying bugs and better optimising the code? Or in helping me package this up as an Extra that could be released for installation through the MODX Manager? All the config options are in the Plugin file itself, it might be nice to create system settings to handle this but I'm not familiar with how to instruct an Extra to create these on installation.

The Caveat - For transparency, I'm not claiming this is 100% original, work and related comments published by Vasiliy Naumkin (bezumkin), Bruno and LuK helped me knock this together.

Hi, it would be nice to see this plugin as Gist or at Pastebin or smthn.

Link to Gist:

https://gist.github.com/chrisdempsey/8b999a40889eef21cb41

Update: should have mentioned the Plugin is dependent on the Resizer extra to handle the actual image resize part.