Assembly assembly = Assembly.GetExecutingAssembly();
string[] names = new string[] { "United_States_of_America", "United_Kingdom", "Australia", "Germany", "France", "Russia", "China", "Japan", "India", "Italy" };

Dictionary<string, Image> images = names.ToDictionary(
    key => key.Replace("_", " "),
    key => ResourceImageHelper.CreateImageFromResources(string.Format("ImageEditOptionsDemo.Resources.Flags.{0}.png", key), assembly));

ImageCollectionEditorInfo editorInfo = new ImageCollectionEditorInfo("Nationality", images, true, true, "Nationality");
EditingFieldExtensions.Instance.RegisterEditorInfo(editorInfo);