Making a file parser sounds like a nightmare that is destined to have bugs for years. I would consider integrating an open-source library that is already mature and used in a lot of projects if it also supports multiple formats, but another reason why handling any user-generated content internally is always a bad idea is that any corrupted file, or anything out of the ordinary may crash/freeze the whole program.
I've seen in the past others using svg by integrating the Edge WebView, rendering it on the side and grabbing an image from it, but that is like turning one room of your house into a walk-in freezer just to have some ice-cubes.