php image recogintion script

need a function to extract the drawing (without the border lines) from a png file (like the pdf i attached) this should work no matter where the box is on the page ( it should only change slightly but may change slightly orientation also) [login to view URL] i can have the colour of the box another colour if it helps i need to be able to pass in the source location of the pdf i need to be able to pass in the destination folder to write the drawing to. extractdrawing($source_of_pdf, $destination_to_write_drawing_to); i need it in pure php i also need the drawing that is extracted in the right orientation. is all this ok ?