PHP - PDF矩形CTM转换

By using PDFParser I have been able to retrieve the PDF's annotations as seen below. I now need to transform the user space (72 DPI) values below to device space (DPI 200).

What calculations do I need to perform to retrieve the device space values?

(
    [1] => Array
    ¦   (   
    ¦   ¦   [URI] => http://blog.blackboard.com/bb-student-a-mobile-app-for-learners-designed-from-the-ground-up/?lang=uki
    ¦   ¦   [Rect] => Array
    ¦   ¦   ¦   (   
    ¦   ¦   ¦   ¦   [0] => 72
    ¦   ¦   ¦   ¦   [1] => 554.25
    ¦   ¦   ¦   ¦   [2] => 535.5
    ¦   ¦   ¦   ¦   [3] => 567.75
    ¦   ¦   ¦   )   
    ¦   )   
)