Uses the IVsImageService2 to convert a KnownMoniker to BitmapSource

KnownMonikersToBitmap.cs

public static BitmapSource GetImage(ImageMoniker moniker, int size)
{
    ImageAttributes imageAttributes = new ImageAttributes();
    imageAttributes.Flags = (uint)_ImageAttributesFlags.IAF_RequiredFlags;
    imageAttributes.ImageType = (uint)_UIImageType.IT_Bitmap;
    imageAttributes.Format = (uint)_UIDataFormat.DF_WPF;
    imageAttributes.LogicalHeight = size;
    imageAttributes.LogicalWidth = size;
    imageAttributes.StructSize = Marshal.SizeOf(typeof(ImageAttributes));

    var service = (IVsImageService2)Microsoft.VisualStudio.Shell.Package.GetGlobalService(typeof(SVsImageService));
    IVsUIObject result = service.GetImage(moniker, imageAttributes);

    object data;
    result.get_Data(out data);

    if (data == null)
        return null;

    return data as BitmapSource;
}