GDAL-RASTER-TRI(1)                   GDAL                   GDAL-RASTER-TRI(1)

NAME
       gdal-raster-tri - Generate a Terrain Ruggedness Index (TRI) map

       Added in version 3.11.


SYNOPSIS

          Usage: gdal raster tri [OPTIONS] <INPUT> <OUTPUT>

          Generate a Terrain Ruggedness Index (TRI) map

          Positional arguments:
            -i, --input <INPUT>                                  Input raster datasets [required]
            -o, --output <OUTPUT>                                Output raster dataset [required]

          Common Options:
            -h, --help                                           Display help message and exit
            --json-usage                                         Display usage as JSON document and exit
            --config <KEY>=<VALUE>                               Configuration option [may be repeated]
            -q, --quiet                                          Quiet mode (no progress bar)

          Options:
            -f, --of, --format, --output-format <OUTPUT-FORMAT>  Output format ("GDALG" allowed)
            --co, --creation-option <KEY>=<VALUE>                Creation option [may be repeated]
            --overwrite                                          Whether overwriting existing output is allowed
                                                                 Mutually exclusive with --append
            --append                                             Append as a subdataset to existing output
                                                                 Mutually exclusive with --overwrite
            -b, --band <BAND>                                    Input band (1-based index) (default: 1)
            --algorithm <ALGORITHM>                              Algorithm to compute TRI. ALGORITHM=Riley|Wilson (default: Riley)
            --no-edges                                           Do not try to interpolate values at dataset edges or close to nodata values

          Advanced Options:
            --if, --input-format <INPUT-FORMAT>                  Input formats [may be repeated]
            --oo, --open-option <KEY>=<VALUE>                    Open options [may be repeated]

DESCRIPTION
       gdal raster tri generates a single-band raster with values computed
       from the elevation. TRI stands for Terrain Ruggedness Index, which
       measures the difference between a central pixel and its surrounding
       cells.

       This subcommand is also available as a potential step of gdal raster
       pipeline

       Value -9999 is used as the nodata value.

       A nodata value in the target dataset will also be emitted if at least
       one pixel set to the nodata value is found in the 3x3 window centered
       around each source pixel. By default, the algorithm will compute values
       at image edges or if a nodata value is found in the 3x3 window, by
       interpolating missing values, unless --no-edges is specified, in which
       case a 1-pixel border around the image will be set with the nodata
       value.

   Standard options

       -f, --of, --format, --output-format <OUTPUT-FORMAT>
              Which output raster format to use. Allowed values may be given
              by gdal --formats | grep raster | grep rw | sort

       --co <NAME>=<VALUE>
              Many formats have one or more optional creation options that can
              be used to control particulars about the file created. For
              instance, the GeoTIFF driver supports creation options to
              control compression, and whether the file should be tiled.

              May be repeated.

              The creation options available vary by format driver, and some
              simple formats have no creation options at all. A list of
              options supported for a format can be listed with the --formats
              command line option but the documentation for the format is the
              definitive source of information on driver creation options.
              See Raster drivers format specific documentation for legal
              creation options for each format.

       --overwrite
              Allow program to overwrite existing target file or dataset.
              Otherwise, by default, gdal errors out if the target file or
              dataset already exists.

       -b, --band <BAND>
              Index (starting at 1) of the band to which the TRI must be
              computed.

       --algorithm Riley|Wilson
              Select the algorithm to use:

              o Riley, the default, uses the square root of the sum of the
                square of the difference between a central pixel and its
                surrounding cells.  This is recommended for terrestrial use
                cases.  It is implemented from Riley, S.J., De Gloria, S.D.,
                Elliot, R. (1999): A Terrain Ruggedness that Quantifies
                Topographic Heterogeneity. Intermountain Journal of Science,
                Vol.5, No.1-4, pp.23-27

              o Wilson uses the mean difference between a central pixel and
                its surrounding cells. This is recommended for bathymetric use
                cases.  It is implemented from Wilson et al. 2007, Marine
                Geodesy 30:3-35.

       --no-edges
              Do not try to interpolate values at dataset edges or close to
              nodata values

GDALG OUTPUT (ON-THE-FLY / STREAMED DATASET)
       This program supports serializing the command line as a JSON file using
       the GDALG output format.  The resulting file can then be opened as a
       raster dataset using the GDALG: GDAL Streamed Algorithm driver, and
       apply the specified pipeline in a on-the-fly / streamed way.

EXAMPLES
   Example 1: Generates a Terrain Ruggedness Index (TRI) map from a DTED0
       file.

          $ gdal raster tri n43.dt0 out.tif --overwrite

AUTHOR
       Even Rouault <even.rouault@spatialys.com>

COPYRIGHT
       1998-2025

                               November 7, 2025             GDAL-RASTER-TRI(1)