[gdal-dev] GeoPDF (TM) vs. GeoSpatial PDF

[David Strip]

On 6/3/2012 10:59 AM, George Demmy wrote:

>> David Strip wrote:

>> >  When used in conjunction with the (free) TerraGo toolbar, the geoPDF
>> >  provides many more capabilities than a geo-spatial pdf, especially if the
>> >  pdf "modify" permission is set.
> As of version 6 which shipped recently, the TerraGo Toolbar offers
> continuous display of coordinates and other functionality for any
> geospatial PDF as long as it can grok the encoding. It supports OGC
> and ISO and uses proj4 via GDAL under the hood for projections. Like
> Reader, Toolbar has some more advanced functionality that is
> accessible if certain permission bits are set.
>
While V6 of the toolbar (and in fact previous versions) provide 
continuous display of coordinates, a "true geoPDF" (which I believe 
means having the LGIDict), has far more coordinate conversion 
capability, as well as the ability to add "geo-marks", geo-located 
stamps (icons) added to the file. I verified this by downloading the 
latest version of the Terrago Toolbar (15.0.0.591). I opened a 
geo-spatial pdf that I created with ArcMap 10.0.2. I can get the 
position display in Lat/Lon and MGRS at the bottom of the image, and in 
the Geolocator tool (from the toolbar), I can also see UTM13N, WGS84, 
USNG, and MGRS. I can't use the GeoMark tools at all. I then open a 
geoPDF (a new generation USGS topo map). In this case I can set the 
GeoLocator projection to display in any of a hundred or more predefined 
projections, or define my own projection parameters. I can also mark the 
map with GeoMarks. The ability to use GeoMarks is not a function of the 
pdf "modify" bit being set. It is set in the ArcMap generated map, which 
I can add non-geospatial marks with other pdf tools.

I belief that the presence of the LGIDict is what enables these other 
features, but I could be wrong.  That's something I've been trying to 
find out.