ComboBox ItemTemplate does not support values of type 'Image'
===

I'm trying to bind a WPF combobox to an observable collection of images.
Here is my collection:

        public class AvatarPhoto
        {
            public int AvatarId { get; set; }
            public BitmapImage AvatarImage { get; set; }
        }
        public ObservableCollection<AvatarPhoto> AvailableProfilePictures { get; private set; }

Here is my xaml:
![enter image description here][1]


  [1]: http://i.stack.imgur.com/iAIsc.png

Visual Studio gives me this compile time error:
Property 'ItemTemplate' does not support values of type 'Image'.

Why is this error seen?

Thanks