Collaboration with Adobe Acrobat and Reader with PDF Naughty Bits

In an earlier post, I discussed some aspects of Adobe's collaboration infrastructure built on top of Acrobat and Reader. It's probably worth talking about some of the details of how this works without the GeoPDF geoconflation. I try to think about how things work, so I'll describe things from that perspective. Let's start with the PDF file.

A PDF file has provisions to store, among other things, two aspects of an electronic document: document content and document structure. For its paper analog, content would be what's printed on the pages and structure would be the order of the pages. Being electronic (why does "electronic" sound dated? maybe "digital" would be better...), PDF can accommodate more bells and whistles than can be placed in a paper book or letter or map or memorandum or summons or fatwa or proclamation or manifesto or whatever: things like interactive bookmarks, hyperlinks, and metadata. In addition to content and structure, PDF has a provision to store annotations. PDF annotations are analogous to sticky notes: they stick on top of the content at a particular location, but are not part of the content. Although perhaps not as ubiquitous as sticky notes, the PDF analog is much more flexible. PDF provides for a variety of annotations, including geometries like polylines and polygons, stamps, clouds, callouts, measurments, interactive 3D, videos, etc. Annotations are not content. They are, in the internals of the PDF file entirely distinct. Addition, removal, and modification of annotations don't modify the PDF content, just as putting a sticky note on that TPS report doesn't change its contents. Yeeeaaahhhh.....

FIG: An Adobe PDF Annotation in Action.

Most annotations can be placed on PDF files out of the box by Adobe Acrobat. Some annotations, like 3D annotations, have to be placed with Acrobat Pro or Pro Extended. Adobe Reader usually cannot modify a PDF file. That's why they call it Reader, and not Modifier, Manipulator, Monkeyer, Munger, or Acrobat. However, Adobe hides little permission bits inside the PDF file that when flipped enable hidden markup tools in Reader and grant permission to use them. In business speak, this is one ways how Adobe "monetizes" Reader. There are two ways to flip those bits: Adobe Acrobat Pro or LiveCycle. The Acrobat method is intended for small work groups and LiveCycle is intended for enterprise work flows.

So, if you want you or someone you love to mark up a PDF file in Adobe Reader, you'll need to have that file enabled for comments by Adobe software. If you don't want to hassle with comment enabling, use Acrobat. Those are the options.

Toolbar is hosted by Acrobat and Reader and plays by the rules dictated by its host environment. If you can't use Adobe's markup tools, you won't be able to use TerraGo's. But that's not the whole story... ready for some geoconflation? Good!

Just as Adobe uses comment enabling to monetize their free Reader, TerraGo uses GeoMark enabling to monetize its free toolbar. Current Publisher and Composer products GeoMark enable by default, but that's only enough to grant TerraGo permssions -- Adobe permissions are required, too. TerraGo Composer can GeoMark enable other geospatial PDF files, such as those created by ESRI ArcMap, Bentley Microstation, and Safe FME.

One thing that's important to note is that this has nothing whatsoever to do with formats, encodings, and openness of standards. TerraGo GeoPDF files are just as open and standards conformant as any other. Just as whether you can markup a PDF file in Reader has nothing to do with the openness of ISO 32000, whether you can access functionality in Toolbar has nothing to do with the openness of the OGC best practice or Adobe's proposed geospatial extensions. Toolbar understands both and Publisher and Composer encode both. Toolbar functionality is tied to permission, not format.