Collaborating in geospatial context since 2000!

Wednesday, May 12, 2010

GeoPDF is not a Format

The name of this blog is GeoPDF. The word GeoPDF has its roots in PDF which is itself is an acronym for Portable Document Format. PDF is defined by an ISO specification. Words like "format" and "specification" might make one think that GeoPDF is a malamanteau of sorts or a perverse play on GeoTIFF. In some sense, the latter is partially correct. GeoPDF has its history in application delivery whereas GeoTIFF has a background in data interoperability. What is GeoPDF? With all due respect to Magritte:
The Treachery of GeoPDF
I like to think of an aspect of GeoPDF -- and PDF -- as an application delivery platform. GeoPDF is the platform on which to build GeoApps. There will be a day when the CamelCased suffixing of Geo to everything will be so redundant as to make no sense, but that day has not arrived. So, on we go with the suffixing. A GeoApp is an application that treats geospatial information as first-class citizens and co-equals of all of the business logic components. But that is for a different post...

Today, GeoPDF is a registered trademark of TerraGo. It's used to brand the mapping products (and GeoApps!) created by TerraGo software. Whether the GeoPDF trademark can withstand xeroxification or genericide of the marketplace remains to be seen. If everybody on the planet uses the word GeoPDF 11 times a day to refer to the geospatial file they mucking with at the time, my job is done and I really won't care if it's generic or not. I imagine a lot of other wonderful things would have had to have happened for that to go down as well.

Today, if a file is created by TerraGo software, it is a GeoPDF file. If it is not created by TerraGo software, it is not a GeoPDF file. This is definitional and the position of TerraGo. I'm not going to defend or debate the rightness or the good-ideaness of the situation in this post, although I welcome comment and debate. GeoPDF encompasses a variety of geospatial encoding flavors, including that described by the OGC best practice as well as Adobe's supplement to ISO 32000. If the georegistration is encoded using OGC, that file is not necessarily GeoPDF. If the georegistration is encoded using Adobe's encoding, that file is not necessarily not GeoPDF. Encoding is irrelevant to GeoPDFness.

GeoPDF is not a format, but it is based on publicly documented format standards and industry best practices. GeoPDF is not defined by its georegistration, but GeoPDF necessarily requires georegistration. GeoPDF is not a data interop or exchange technology, but it certainly can be used for interop if care is taken for those purposes. More on this latter point in a subsequent post.

GeoPDF® is a trademark, but that is of (almost) least interest to me.

As always, the stuff I write here is not the official word-o-TerraGo, but my opinion. I have attempted to describe the official position, but this is not an official position document. Just trying to fill in between the lines...


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