Nokia Lumia 1020 with frozen "film grain" type screen

[WPCentral Question]

My Nokia Lumia 1020 froze with a light "film grain" type screen. I can lock it but the part where the clock is goes into a grainy rectangle. I can't turn the phone off and it won't reset. Any ideas?

 

[Laura Knotek]

Are you using Glance screen?