gdallocationinfo(1)					      General Commands Manual					       gdallocationinfo(1)

NAME

       gdallocationinfo - gdallocationinfo raster query tool

SYNOPSIS

       Usage: gdallocationinfo [--help-general] [-xml] [-lifonly] [-valonly]
			       [-b band]* [-l_srs srs_def] [-geoloc] [-wgs84]
			       srcfile [x y]

DESCRIPTION

       The gdallocationinfo utility provide a mechanism to query information about a pixel given it's location in one of a variety of coordinate
       systems. Several reporting options are provided.

       -xml:
	   The output report will be XML formatted for convenient post processing.

       -lifonly:
	   The only output is filenames production from the LocationInfo request against the database (ie. for identifying impacted file from
	   VRT).

       -valonly:
	   The only output is the pixel values of the selected pixel on each of the selected bands.

       -b band:
	   Selects a band to query. Multiple bands can be listed. By default all bands are queried.

       -l_srs srs def:
	   The coordinate system of the input x, y location.

       -geoloc:
	   Indicates input x,y points are in the georeferencing system of the image.

       -wgs84:
	   Indicates input x,y points are WGS84 long, lat.

       srcfile:
	   The source GDAL raster datasource name.

       x:  X location of target pixel. By default the coordinate system is pixel/line unless -l_srs, -wgs84 or -geoloc supplied.

       y:  Y location of target pixel. By default the coordinate system is pixel/line unless -l_srs, -wgs84 or -geoloc supplied.

       This utility is intended to provide a variety of information about a pixel. Currently it reports three things:

       o The location of the pixel in pixel/line space.
       o The result of a LocationInfo metadata query against the datasource - currently this is only implemented for VRT files which will report
	 the file(s) used to satisfy requests for that pixel.
       o The raster pixel value of that pixel for all or a subset of the bands.
       o The unscaled pixel value if a Scale and/or Offset apply to the band.
       The pixel selected is requested by x/y coordinate on the commandline, or read from stdin. More than one coordinate pair can be supplied
       when reading coordinatesis from stdin. By default pixel/line coordinates are expected. However with use of the -geoloc, -wgs84, or -l_srs
       switches it is possible to specify the location in other coordinate systems.
       The default report is in a human readable text format. It is possible to instead request xml output with the -xml switch.
       For scripting purposes, the -valonly and -lifonly switches are provided to restrict output to the actual pixel values, or the LocationInfo
       files identified for the pixel.
       It is anticipated that additional reporting capabilities will be added to gdallocationinfo in the future.
EXAMPLE

       Simple example reporting on pixel (256,256) on the file utm.tif.
       $ gdallocationinfo utm.tif 256 256
       Report:
	 Location: (256P,256L)
	 Band 1:
	   Value: 115
       Query a VRT file providing the location in WGS84, and getting the result in xml.
       $ gdallocationinfo -xml -wgs84 utm.vrt -117.5 33.75
       <Report pixel="217" line="282">
	 <BandReport band="1">
	   <LocationInfo>
	     <File>utm.tif</File>
	   </LocationInfo>
	   <Value>16</Value>
	 </BandReport>
       </Report>
AUTHORS

       Frank Warmerdam warmerdam@pobox.com

GDAL
								  Tue Sep 18 2012					       gdallocationinfo(1)