How do I prevent Grav from "compressing" my page media?

What I mean by this is, when I upload a JPG file to Grav via the page media drag and drop it's then using some really poor compression tool which is converting from a 386kb JPG to a 1.7mb PNG file!!

How to I stop Grav doing this so I can use my optimised JPG images?

Turns out this compression is happening on the actual page, rather than via the admin panel. So what is actually compressing this image and increasing its size?

All the media processing that Grav does is via GD. GD is a built-in PHP library for image manipulation. it does not produce optimally compressed file sizes. If you don't want to have the image manipulated, simply access the image directly and don't perform any media operations on it (resize, colorize, etc).