Is it possible to use mod_negotiation to serve up a webp image if the browser supports it, and a jpg otherwise?

For instance, if I link to an image with the path /images/test, it serves the image found at /images/test.webp if the UA knows about webp, or jpg otherwise?

I've tried poking around, but it seems that the Accept headers in Chrome at least look like Accept:*/*, rather than specifying the image type.

If this isn't the way to do it, has anyone got any other suggestions?