I need help - I can help - Geospatial PDF

Print Page | Close Window

Geospatial PDF

Printed From: Debenu Quick PDF Library - PDF SDK Community Forum
Category: For Users of the Library
Forum Name: I need help - I can help
Forum Description: Problems and solutions while programming with the Debenu Quick PDF Library and Debenu PDF Viewer SDK
URL: http://www.quickpdf.org/forum/forum_posts.asp?TID=1577
Printed Date: 06 May 25 at 4:19PM
Software Version: Web Wiz Forums 11.01 - http://www.webwizforums.com

Topic: Geospatial PDF

Posted By: bakerlp
Subject: Geospatial PDF
Date Posted: 21 Sep 10 at 1:22PM

Hi,

I am wondering whether QuickPDF supports georeferenced PDF in accordance with ISO 32000.

I've made use of QuickPDF for processing GeoPDF files (TerraGO) through the 'GetPageLGIDictContent' API and all is well. However I would also like to read the geo data from so called geospatial PDF's where the geo data is encoded in accordance with 'Adobe Supplement to ISO32000'.

Any assistancew would be appreciated.

Lee

Replies:

Posted By: Ingo
Date Posted: 21 Sep 10 at 9:03PM

Hi Lee!

Perhaps this link can help?
http://www.quickpdf.org/forum/geopdf_topic1321_post6394.html?KW=geospatial#6394
Real support you won't get from the current version of QuickPDF.

Cheers and welcome here,
Ingo

Posted By: bakerlp
Date Posted: 21 Sep 10 at 10:01PM

Ingo,

Many thanks for the reply. The link you refer to seems to be discussing geopdf's in accordance with " http://portal.opengeospatial.org/files/?artifact_id=33332 - GeoPDF Encoding Best Practice Version 2.2 " which can be processed using Quickpdf's API GetPageLGIDictContent.

I downloaded the ' http://acrobatusers.com/content/intelligence-collection-using-geopdf - Intelligence Collection using GeoPDF ' geopdf from 'http://acrobatusers.com/gallery/geospatial' and the the value returned from GetPageLGIDictCount is zero hence there doesn't seem to be any geo-reference data embedded. However, If I open the file in Acrobat Reader 9 then I can view the Lat/Long via the acorbat 'Analysis' menu hence there is some geodata in the file somewhere, its just how to extract it.

Many thanks
Lee

Posted By: Ingo
Date Posted: 22 Sep 10 at 6:36AM

Hi Lee!

Do you know what are the special signs, characters, ... from "these geospatial things" in the pdf-content?
If "Yes"... why not search inside the pdf-content programmatically by yourself to extract the relevant content?
I've done similar things with javascript- and xml-code...

Cheers, Ingo

Posted By: bakerlp
Date Posted: 22 Sep 10 at 9:40AM

Hi Ingo,

Unfortunately I do not know the tags/signs involved (if there are any). I simply downloaded the file and tried to process it as if a TerraGO GeoPDF.

If the geo-reference data is encoded in accordance with ISO 32000 (Extension Level 3) (using entries in a viewport dictionary) then is this supported by QuickPDf. If yes then a heads up on the API's involved would be very much appreciated.

Ingo...apologies but I'm very new to PDF programming so I may be asking rudimentary questions.

Thanks

Lee

Posted By: Ingo
Date Posted: 22 Sep 10 at 2:24PM

Hi Lee!

You can get more from inside as you can imagine ;-)
Load the pdf and save it decrypted.
Then take notepad and search directly into the content.
Perhaps you can find the special strings... keep it in mind...
and use it later programmatically ;-)
Have a look in my blog regarding this case to get an idea
about what you can do:
http://pdfcomments.blogspot.com/2009/09/under-surface.html

Cheers, Ingo

Posted By: cosina
Date Posted: 28 Sep 10 at 11:11PM

I'm also very intereted in Adobe's own Geospatial specification support (of course just in a matter of reading/writing a proper section)

Documenation:
http://www.adobe.com/content/dam/Adobe/en/devnet/pdf/pdfs/adobe_supplement_iso32000.pdf - http://www.adobe.com/content/dam/Adobe/en/devnet/pdf/pdfs/adobe_supplement_iso32000.pdf
8.8.1 Geospatial Features

Sample file:
http://www.avenza.com/sites/default/files/spatialpdf/US_County_Populations.pdf - http://www.avenza.com/sites/default/files/spatialpdf/US_County_Populations.pdf

Posted By: Ingo
Date Posted: 29 Sep 10 at 6:33AM

Hi!

Thanks for the sample link.
If you do like i've suggested opening the pdf with notepad
you'll find this section regarding Geospatial:
/Type /Measure
/Bounds [ 0.000000 0.000000 0.000000 1.000000 1.000000 1.000000 1.000000 0.000000 ]
/GCS 218 0 R
/GPTS [ 35.662407 -94.909767 36.294361 -94.899741 36.284127 -94.028131 35.652254 -94.046095 ]
/LPTS [ 0.500000 0.500000 0.500000 0.518145 0.513570 0.518145 0.513570 0.500000 ]
/PDU [ /M /SQM /DEG ]
/Subtype /GEO
>>
endobj
218 0 obj
<<
/Type /PROJCS
/WKT (PROJCS["North_America_Albers_Equal_Area_Conic",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137,298.257222101]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Albers"],PARAMETER["false_easting",0],PARAMETER["false_northing",0],PARAMETER["latitude_of_origin",40],PARAMETER["central_meridian",-96],PARAMETER["standard_parallel_1",20],PARAMETER["standard_parallel_2",60],UNIT["Meter",1]])
>>
endobj

Cheers, Ingo