How to get page orientation on a PDF page?

Question

The getPageDimensions (CAM :: PDF) function returns the same values ​​for both portrait and landscape pages. How to determine 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 ways to identify this are also welcome (preferably using Perl lib).

Thanks.

Answer 1

I am the author of CAM :: PDF.

Well, there are two parts. One of them is page sizes, as you noted. This works as expected: I used Apple Preview.app to rotate the PDF file and ran these two 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 also the attribute of the `/ Rotate 'page. An argument is the number of degrees (the default is 0, but 90 or 270 are not uncommon). Like page sizes, this is a property of the inherited property, so you need to go to the 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";