[Geotiff] Processing Elevation data in Geotiff

[Chandrakant Mohire (RBIN/ECM2)]

Hello ,

Firstly I am  new to the geotiff world .


I am trying to  read DEM data which is supplied in geotiff format. Its
geotiff image with 181 rows x 181 cols
I  wrote some code to read the basic tags. And they are as follows

SAMPLESPERPIXEL  1 
TIFFTAG_BITSPERSAMPLE  16
TIFFTAG_PHOTOMETRIC  1     (1       /* min value is black */ )
TIFFTAG_PLANARCONFIG  1   ( single plane image) 

Now my doubt how do I read the height data stored in this Geotiff Image
?
And is this height stored relative to some value ( like any value seen
in  ModelTiepointTag  .. ) 

Any API's in libgeotiff  / pointers on handling Digital Elevation data
in geotiff will be appreciated .



FYI ..
This is the Geotiff info for the input data 

Geotiff_Information:
   Version: 1
   Key_Revision: 1.0
   Tagged_Information:
      ModelTiepointTag (2,3):
         0                0                0                
         6.99861111       54.0013889       0                
      ModelPixelScaleTag (1,3):
         0.00277778       0.00277778       0                
      End_Of_Tags.
   Keyed_Information:
      GTModelTypeGeoKey (Short,1): ModelTypeGeographic
      GTRasterTypeGeoKey (Short,1): RasterPixelIsArea
      GeographicTypeGeoKey (Short,1): GCS_WGS_84
      GeogCitationGeoKey (Ascii,6): "wgs84"
      GeogAngularUnitsGeoKey (Short,1): Angular_Degree
      End_Of_Keys.
   End_Of_Geotiff.


Thanks in advance,
--Chandrakant







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