Reference point (in Revit) to which the image is going to be inserted. 
   Namespace:   Autodesk.Revit.DB  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
Syntax
Remarks
 If    a null reference (  Nothing  in Visual Basic)  , the image will be inserted to the Revit's origin.