GDALLOCATIONINFO(1)

NAME
gdallocationinfo - Raster query tool.

SYNOPSIS

            Usage: gdallocationinfo [--help] [--long-usage] [--help-general]
                                    [-xml] [-lifonly] [-valonly] [-E] [-field_sep <sep>]
                                    [-ignore_extra_input] [-b <band>]...
                                    [-overview <overview_level>]
                                    [-r nearest|bilinear|cubic|cubicspline]
                                    [[-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 its location in one of a variety of coordinate systems. Several reporting options are provided.

TIP:
        Equivalent in new "gdal" command line interface:

        See gdal raster pixel-info.

    --help
        Show this help message and exit

    --help-general
        Gives a brief usage message for the generic GDAL commandline options and exit.

    -xml
        The output report will be XML formatted for convenient post processing. (Example 2).

    -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. By default, the value of each band is output on a separate line, unless -field_sep is specified.

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

    -r {nearest|bilinear|cubic|cubicspline}
        Added in version 3.10.

        Select a sampling algorithm. The default is nearest.

        The available methods are:

        nearest applies a nearest neighbour.

        bilinear applies a bilinear convolution kernel.

        cubic applies a cubic convolution kernel.

        cubicspline applies a B-Spline convolution kernel.

    -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>
        Dataset open option (format specific)

    -ignore_extra_input
        Added in version 3.9.

        Set this flag to avoid extra non-numeric content at end of input lines to be appended to the output lines in -valonly mode (requires -field_sep to be also defined), or as a dedicated field in default or -xml modes.

    -E  Added in version 3.9.

        Enable Echo mode, where input coordinates are prepended to the output lines in -valonly mode.

    -field_sep <sep>
        Added in version 3.9.

        Defines the field separator, used in -valonly mode, to separate different values. It defaults to the new-line character, which means that when querying a raster with several bands, the output will contain one value per line, which may make it hard to recognize which value belongs to which set of input x,y points when several ones are provided. Defining the field separator is also needed

    <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:

    •   The location of the pixel in pixel/line space.

    •   The result of a LocationInfo metadata query against the datasource. This is implemented for VRT files which will report the file(s) used to satisfy requests for that pixel, and by the MBTiles driver.

    •   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 integer 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.

RETURN STATUS CODE

The program returns status code 0 in case of success, and non-zero in case of error (non-blocking errors emitted as warnings are considered as a successful execution).

EXAMPLES

  Example 1: Reporting on pixel (256,256) on the file utm.tif

            $ gdallocationinfo utm.tif 256 256
            Report:
            Location: (256P,256L)
            Band 1:
                Value: 115

  Example 2: Querying 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>

  Example 3: Reading locations from stdin

            $ cat coordinates.txt
            443020 3748359
            441197 3749005
            443852 3747743

            $ cat coordinates.txt | gdallocationinfo -geoloc utmsmall.tif
            Report:
              Location: (38P,49L)
              Band 1:
                Value: 214
            Report:
              Location: (7P,38L)
              Band 1:
                Value: 107
            Report:
              Location: (52P,59L)
              Band 1:
                Value: 148

            $ cat coordinates.txt | gdallocationinfo -geoloc -valonly -E -field_sep , utmsmall.tif
            443020,3748359,214
            441197,3749005,107
            443852,3747743,148

AUTHOR
Frank Warmerdam <warmerdam@pobox.com>

COPYRIGHT
1998-2026