Question

The function getPageDimensions (of CAM::PDF) returns same values for both portrait and landscape pages. How can I identify the orientation of a PDF page? I am using CAM::PDF Perl library and would like to know how to do this using this library. But any other means to identify this is also welcome (preferably using a Perl lib).

Thanks.

Answer 1

I’m the author of CAM::PDF.

Well, there’s two parts to this. One is the page’s dimensions, as you noted. That works as expected: I used Apple’s Preview.app to rotate a PDF file and ran these two command lines:

perl -MCAM::PDF -le'print '@{[CAM::PDF->new(shift)->getPageDimensions(1)]}'' orig.pdf  0 0 612 792 perl -MCAM::PDF -le'print '@{[CAM::PDF->new(shift)->getPageDimensions(1)]}'' rotated.pdf  0 0 792 612 

But there’s also the `/Rotate’ page attribute. The argument is a number of degrees (default 0, but 90 or 270 are not uncommon). Like page dimensions, it’s an inheritable property so you have to navigate to parent pages. Here’s a quick-and-dirty command line tool to output the rotation value:

use CAM::PDF; my $filename = shift || die; my $pagenum = shift || die; my $pdf = CAM::PDF->new($filename) || die; my $pagedict = $pdf->getPage($pagenum); my $rotate = 0; while ($pagedict) {    $rotate = $pdf->getValue($pagedict->{Rotate});    if (defined $rotate) {       last;    }    my $parent = $pagedict->{Parent};    $pagedict = $parent && $pdf->getValue($parent); } print '/Rotate $rotate\n';