Get the UserUnit scaling factor for the specified page.
double pdfGetPageUserUnit(PDFHandle pdf, int page)
This function returns the UserUnit, i.e., scaling factor, for the specified page. The UserUnit can be used to create pages larger than the normal maximum page size. In most PDF files, the UserUnit is 1.0.
double uu; uu = pdfGetPageUserUnit(pdf, pageNum);