gdallocationinfo(1)
NAME
gdallocationinfo - gdallocationinfo raster query tool
SYNOPSIS
Usage: gdallocationinfo [--help-general] [-xml] [-lifonly] [-valonly]
[-b band]* [-overview overview_level]
[-l_srs srs_def] [-geoloc] [-wgs84]
[-oo NAME=VALUE]* 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 (i.e. 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.
-overview overview_level:
Query the (overview_level)th overview (overview_level=1 is the 1st
overview), instead of the base band. Note that the x,y location (if
the coordinate system is pixel/line) must still be given with
respect to the base band.
-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.
-oo NAME=VALUE:
(starting with GDAL 2.0) Dataset open option (format specific)
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:
* The location of the pixel in pixel/line space.
* 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.
* The raster pixel value of that pixel for all or a subset of the
bands.
* 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 command line,
or read from stdin. More than one coordinate pair can be supplied when
reading coordinates 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
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