[QGIS-trac] Re: [Quantum GIS] #2987: Auto GCP detection library

[Quantum GIS]

#2987: Auto GCP detection library
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   Reporter:  jamesm6162        |              Owner:  timlinux     
       Type:  patch             |             Status:  assigned     
   Priority:  minor: annoyance  |          Milestone:  Version 1.6.0
  Component:  C++ Plugins       |            Version:  Trunk        
   Keywords:                    |   Platform_version:               
   Platform:  Debian            |           Must_fix:  No           
Status_info:  0                 |  
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Comment(by timlinux):

 Replying to [comment:12 jamesm6162]:
 > Hi Tim
 >
 > Thanks for the feedback. We are working on getting all the crashes fixed
 adn we'll get to all your recommended features as soon as possible.
 >
 > One question from my side though.
 > What would be the best resource to start looking at if we want to
 implement the Georeferencing with GDAL?
 >
 > Thanks
 >
 > James
 >
 >

 Using gdal_translate either via the python api (I've never tried so you
 will need to check their docs) or by doing a shell call from python. Below
 is an example from some code of mine:

 {{{
 myString = "gdal_translate -a_srs 'EPSG:4326' -gcp 0 0 %s %s -gcp %s 0 %s
 %s -gcp %s %s %s %s -gcp 0 %s %s %s -of GTIFF -co COMPRESS=DEFLATE -co
 TILED=YES %s %s" % ( \
          myTL[0], myTL[1], \
          myImageXDim, myTR[0],myTR[1], \
          myImageXDim, myImageYDim, myBR[0],myBR[1], \
          myImageYDim, myBL[0],myBL[1], \
          myPath, \
          myOutputPath )
    print myString
    os.system( myString )
 }}}

 You can add as many -gcp parameters as you like. My example above simply
 georeferences the corners hence the hard coded 0's. You can verify your
 GCPs in the output file by calling gdaoinfo on it.

 Hope that helps!

 Regards

 Tim

-- 
Ticket URL: <http://trac.osgeo.org/qgis/ticket/2987#comment:15>
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