[feature request] support webp image format

[ustk]

If not too hard to implement, this would be nice to have, essentially when downloading an image from the server where every file is in this format already...

[Dan Korneff]

I'm in need of this as well.
Looks like there's a solution here:
https://github.com/FigBug/Gin/tree/master/modules/gin_webp

Might give it a try this weekend.