My application let the user upload a PDF for printing. I want to know dynamically the recommended ISO page print size (i.e. A3, A2...)
One solution is with Apache PDFBox to take the page dimension and divide in 72 to get the inch size.
There is other way more accurate to do it, that also round dynamically the dimensions if needed? (i.e. if for example A4 is 8.3 x 11.7 in, what happened if the dimension is 9 x 12 in?)
There is rule of thumb for recommended rounding?