PDFsharp & MigraDoc Foundation

I am trying to lay an image over a existing text field.

I can find the Rect of the text field using:

PdfRectangle txtRect = txtField.Elements.GetRectangle("/Rect");

But when I extract the X/Y coords and use it with gfx.DrawImage the positioning for Left is perfect, but the Top positioning is always off.

What are the text field Rect coords in reference to?

What is the best XGraphics creation method to use only knowing the X/Y of the text field, currently I am using FromPdfPage.

I know this isn't constructive, but just in case others are searching.

I couldn't find a way to do it with PDFsharp or ITextSharp Libraries. If you are on a Microsoft platform AspPDF does the job easy.