11. The method of claim 10 , wherein generating the ordered tree structure of the graphical content portions includes: adding structural data to the graphical content portions.
11. The method of claim 10 , wherein generating the ordered tree structure of the graphical content portions includes: adding structural data to the graphical content portions. 12. The method of claim 11 , wherein analyzing the drawing commands includes: analyzing drawing commands from a portable document format (PDF) file, the PDF file lacking complete structural data to define a read order of the graphical content portions.