[GRASS-dev] [GRASS GIS] #67: r.out.gdal type= and no-data issues

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1

#67: r.out.gdal type= and no-data issues
----------------------+-----------------------------------------------------
Reporter: sieczka | Owner: grass-dev@lists.osgeo.org
     Type: defect | Status: new
Priority: critical | Milestone: 6.3.0
Component: default | Version: unspecified
Keywords: |
----------------------+-----------------------------------------------------
If data 'type' is not specified and the input raster has nulls, r.out.gdal
picks a correct datatype automatically, but sets a bogus no-data value.
Example, in spearfish60:

{{{
r.out.gdal in=geology out=gelogy.tif
Exporting to GDAL data type: Byte
  100%
WARNING: Input raster map constains cells with NULL-value (no-data). For
          no-data values was used value -2147483648. You can specify nodata
          value by nodata parameter.
r.out.gdal complete.
}}}

Note the bogus -2147483648 no-data value, not in Byte datatype range.

If the user specifies 'type=Byte' explicitely, r.out.gdal sets nodata to
255 by default (OK):

{{{
GRASS 6.3.svn (spearfish60):~ > r.out.gdal in=geology out=gelogy2.tif
type=Byte
Exporting to GDAL data type: Byte
  100%
WARNING: Input raster map constains cells with NULL-value (no-data). For
          no-data values was used value 255. You can specify nodata value
by
          nodata parameter.
r.out.gdal complete.
}}}

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/67&gt;
GRASS GIS <http://grass.osgeo.org>
GRASS Geographic Information System (GRASS GIS) - http://grass.osgeo.org/

2

#67: r.out.gdal type= and no-data issues
-----------------------+----------------------------------------------------
  Reporter: sieczka | Owner: martinl
      Type: defect | Status: assigned
  Priority: critical | Milestone: 6.3.0
Component: default | Version: unspecified
Resolution: | Keywords: gdal
-----------------------+----------------------------------------------------
Changes (by martinl):

  * keywords: => gdal
  * status: new => assigned
  * owner: grass-dev@lists.osgeo.org => martinl
* cc: grass-dev@lists.osgeo.org (added)

Comment:

Please test the attached patch. Martin

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Ticket URL: <http://trac.osgeo.org/grass/ticket/67#comment:1&gt;
GRASS GIS <http://grass.osgeo.org>
GRASS Geographic Information System (GRASS GIS) - http://grass.osgeo.org/

3

#67: r.out.gdal type= and no-data issues
-----------------------+----------------------------------------------------
  Reporter: sieczka | Owner: martinl
      Type: defect | Status: assigned
  Priority: critical | Milestone: 6.3.0
Component: default | Version: unspecified
Resolution: | Keywords: gdal
-----------------------+----------------------------------------------------
Changes (by neteler):

* cc: warmerdam (added)

Comment:

I darkly remember that GDAL uses out-of-range values for no data.
Possible?

See also

http://lists.osgeo.org/pipermail/grass-dev/2007-May/031316.html

http://lists.osgeo.org/pipermail/grass-dev/2007-May/031715.html

Markus

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/67#comment:2&gt;
GRASS GIS <http://grass.osgeo.org>
GRASS Geographic Information System (GRASS GIS) - http://grass.osgeo.org/

4

#67: r.out.gdal type= and no-data issues
-----------------------+----------------------------------------------------
  Reporter: sieczka | Owner: martinl
      Type: defect | Status: assigned
  Priority: critical | Milestone: 6.3.0
Component: default | Version: unspecified
Resolution: | Keywords: gdal
-----------------------+----------------------------------------------------
Comment (by martinl):

Replying to [comment:2 neteler]:
> I darkly remember that GDAL uses out-of-range values for no data.
Possible?
>
> See also
>
> http://lists.osgeo.org/pipermail/grass-dev/2007-May/031316.html
>
> http://lists.osgeo.org/pipermail/grass-dev/2007-May/031715.html

this should be already fixed, see r29555.

Martin

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/67#comment:3&gt;
GRASS GIS <http://grass.osgeo.org>
GRASS Geographic Information System (GRASS GIS) - http://grass.osgeo.org/

5

#67: r.out.gdal type= and no-data issues
-----------------------+----------------------------------------------------
  Reporter: sieczka | Owner: martinl
      Type: defect | Status: assigned
  Priority: critical | Milestone: 6.3.0
Component: default | Version: unspecified
Resolution: | Keywords: gdal
-----------------------+----------------------------------------------------
Comment (by martinl):

Replying to [comment:1 martinl]:
> Please test the attached patch. Martin

Patch applied in trunk, r30433. Martin

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/67#comment:4&gt;
GRASS GIS <http://grass.osgeo.org>
GRASS Geographic Information System (GRASS GIS) - http://grass.osgeo.org/

6

#67: r.out.gdal type= and no-data issues
-----------------------+----------------------------------------------------
  Reporter: sieczka | Owner: martinl
      Type: defect | Status: closed
  Priority: critical | Milestone: 6.3.0
Component: default | Version: unspecified
Resolution: fixed | Keywords: gdal
-----------------------+----------------------------------------------------
Changes (by martinl):

  * status: assigned => closed
  * resolution: => fixed

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/67#comment:5&gt;
GRASS GIS <http://grass.osgeo.org>
GRASS Geographic Information System (GRASS GIS) - http://grass.osgeo.org/