[gdal-dev] Re: Problem with GEOTIFF

[Fernando Cacciola]

Hi Frank,

Thanks for the reply.

On 1/26/2011 11:16 PM, Frank Warmerdam wrote:
> On 11-01-25 03:09 PM, Fernando Cacciola wrote:
>> Hello,
>>
>> I have a geotiff image which, according to its accompaning htm, uses the
>> WGS_1984 Datum.
>>
>> However, when I call GDALGetProjectionRef() it fails, returning
>> "GCS tag not found", plus
>>
>> ENR_L01.tif (from ENR_L01.zip)
>> Failed to setup Geographic Coordinate System
>> FAILED with error: 2
> ...
>>
>>
>> What can I do?
>
> Fernando,
>
> It might be helpful to see a listgeo report on the tiff file. Listgeo
> is a utility associated with libgeotiff and might already be available on
> your system or easily installed.
>
OK, I have it already so here is the information:

Corner Coordinates:
  ... unable to transform points between pixel/line and PCS space
Geotiff_Information:
    Version: 1
    Key_Revision: 1.0
    Tagged_Information:
       End_Of_Tags.
    Keyed_Information:
       End_Of_Keys.
    End_Of_Geotiff.

I noticed that this dataset is made of 4 files:

enr_p01.aux
enr_p01.tfwx
enr_p01.tif
enr_p01.tif.aux.xml

Oddly, the xml file contains this tag:

<WKT>PROJCS[&quot;Pac_chart&quot;,GEOGCS[&quot;GCS_WGS_1984&quot;,DATUM[&quot;D_WGS_1984&quot;.....

so it seems like the data is there after all.

> I haven't been able to identify where the "GCS tag not found" error message
> is coming from. It does not seem to be part of the OGRSpatialReference,

That is the content of the string returned by GDALGetProjectionRef()

Best

-- 
---
Fernando Cacciola
SciSoft Consulting, Founder
http://www.scisoft-consulting.com