Can Still Images Fade In and Fade Out?

I have some video in my iMovie project where the "star" mentions her kids. When she says the kid's name, I've placed a still image above that spot on the timeline so you see the kid instead of his mom for a few seconds. Instead of popping into view and then disappearing, I want the still image to quickly fade up from black and then fade out quickly at the end. When I was using Final Cut Pro in my job, this was easy, but I can't find any way to do it in iMovie. Any ideas?