Skip site navigation (1)Skip section navigation (2)

  
 
  

home | help
GDAL-RASTER-CONTOUR(1)		      GDAL		  GDAL-RASTER-CONTOUR(1)

NAME
     gdal-raster-contour  -  Creates  a  vector  contour from a raster elevation
     model (DEM)

     Added in version 3.11.

SYNOPSIS
	Usage: gdal raster contour [OPTIONS] <INPUT> <OUTPUT>

	Creates a vector contour from a raster elevation model (DEM).

	Positional arguments:
	  -i, --input <INPUT>				       Input raster datasets [required] [not available in pipelines]
	  -o, --output <OUTPUT> 			       Output vector dataset [required] [not available in pipelines]

	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 or warning message) [not available in pipelines]

	Options:
	  -f, --of, --format, --output-format <OUTPUT-FORMAT>  Output format ("GDALG" allowed) [not available in pipelines]
	  --co, --creation-option <KEY>=<VALUE> 	       Creation option [may be repeated] [not available in pipelines]
	  --lco, --layer-creation-option <KEY>=<VALUE>	       Layer creation option [may be repeated] [not available in pipelines]
	  --overwrite					       Whether overwriting existing output dataset is allowed [not available in pipelines]
	  --output-layer <OUTPUT-LAYER> 		       Output layer name
	  -b, --band <BAND>				       Input band (1-based index) (default: 1)
	  --elevation-name <ELEVATION-NAME>		       Name of the elevation field
	  --min-name <MIN-NAME> 			       Name of the minimum elevation field
	  --max-name <MAX-NAME> 			       Name of the maximum elevation field
	  --3d						       Force production of 3D vectors instead of 2D
	  --input-nodata <INPUT-NODATA> 		       Input pixel value to treat as 'nodata'
	  --interval <INTERVAL> 			       Elevation interval between contours
							       Mutually exclusive with --levels, --exp-base
	  --levels <LEVELS>				       List of contour levels [may be repeated]
							       Mutually exclusive with --interval, --exp-base
	  -e, --exp-base <EXP-BASE>			       Base for exponential contour level generation
							       Mutually exclusive with --interval, --levels
	  --off, --offset <OFFSET>			       Offset to apply to contour levels
	  -p, --polygonize				       Create polygons instead of lines
	  --group-transactions <GROUP-TRANSACTIONS>	       Group n features per transaction (default 100 000)

	Advanced Options:
	  --if, --input-format <INPUT-FORMAT>		       Input formats [may be repeated] [not available in pipelines]
	  --oo, --open-option <KEY>=<VALUE>		       Open options [may be repeated] [not available in pipelines]
	  --output-oo, --output-open-option <KEY>=<VALUE>      Output open options [may be repeated] [not available in pipelines]

DESCRIPTION
     gdal raster contour creates a vector contour from a raster elevation  model
     (DEM).

     Since GDAL 3.12, this algorithm can be part of a gdal pipeline.

     Added in version 3.12.

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 vector
     dataset using the GDALG: GDAL Streamed  Algorithm	driver,  and  apply  the
     specified pipeline in a on-the-fly / streamed way.

     NOTE:
	However  this  algorithm  is  not  natively streaming compatible. Conse-
	quently a in-memory temporary dataset will be generated, which may cause
	significant processing time at opening.

PROGRAM-SPECIFIC OPTIONS
     --3d   Forces the production of 3D vectors instead of 2D.	Includes  eleva-
	    tion at every vertex.

     -b, --band <BAND>
	    Picks a particular band to get the DEM from. Defaults to band 1.

     --elevation-name <ELEVATION-NAME>
	    Provides  a name for the attribute in which to put the elevation. If
	    not provided no elevation attribute is attached. Ignored in  polygo-
	    nal contouring (-p) mode.

     -e, --exp-base <EXP-BASE>
	    Generate levels on an exponential scale: base ^ k, for k an integer.
	    Mutually exclusive with --interval, --levels.

     --group-transactions <GROUP-TRANSACTIONS>
	    Group n features per transaction (default 100 000).

     --interval <INTERVAL>
	    Elevation	interval   between  contours.  Mutually  exclusive  with
	    --levels, --exp-base.  The first contour will be  generated  at  the
	    first  multiple of INTERVAL which is greater than the raster minimum
	    value.

     --levels <LEVELS>
	    List of contour levels. MIN and MAX are special values  that  repre-
	    sent  the  minimum and maximum values in the raster.  When --polygo-
	    nize is used, the specified values are used as bounds of the  gener-
	    ated polygons.  Mutually exclusive with --interval, --exp-base.

     --max-name <MAX-NAME>
	    Provides a name for the attribute in which to put the maximum eleva-
	    tion.  If  not  provided no maximum elevation attribute is attached.
	    Ignored in polygonal contouring (-p) mode.

     --min-name <MIN-NAME>
	    Provides a name for the attribute in which to put the minimum eleva-
	    tion. If not provided no minimum elevation	attribute  is  attached.
	    Ignored in polygonal contouring (-p) mode.

     --off, --offset <OFFSET>
	    Offset from zero relative to which to interpret intervals.

     --nln, --output-layer <OUTPUT-LAYER>
	    Provides a name for the output vector layer. Defaults to "contour".

     -p, --polygonize
	    Create polygons instead of lines.

     --input-nodata <INPUT-NODATA>
	    Input pixel value to treat as 'nodata'.

STANDARD OPTIONS
     --co, --creation-option <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 sim-
	    ple formats have no creation options at all. A list of options  sup-
	    ported  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  for-
	    mat  specific documentation for legal creation options for each for-
	    mat.

     --if, --input-format <format>
	    Format/driver name to be attempted to open the input file(s). It  is
	    generally  not  necessary  to specify it, but it can be used to skip
	    automatic driver detection, when it fails to select the  appropriate
	    driver.   This  option can be repeated several times to specify sev-
	    eral candidate drivers.  Note that it does not force  those  drivers
	    to	open  the dataset. In particular, some drivers have requirements
	    on file extensions.

	    May be repeated.

     --lco, --layer-creation-option <NAME>=<VALUE>
	    Many formats have one or more optional layer creation  options  that
	    can  be used to control particulars about the layer created. For in-
	    stance, the GeoPackage driver supports  layer  creation  options  to
	    control  the feature identifier or geometry column name, setting the
	    identifier or description, etc.

	    May be repeated.

	    The layer creation options available vary by format driver, and some
	    simple formats have no layer creation options at all. A list of  op-
	    tions  supported  for a format can be listed with the --formats com-
	    mand line option but the documentation for the format is the defini-
	    tive source of information on driver creation options.   See  Vector
	    drivers format specific documentation for legal creation options for
	    each format.

	    Note that layer creation options are different from dataset creation
	    options.

     --oo, --open-option <NAME>=<VALUE>
	    Dataset open option (format specific).

	    May be repeated.

     --output-open-option, --output-oo <NAME>=<VALUE>
	    Added in version 3.12.

	    Dataset open option for output dataset (format specific).

	    May be repeated.

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

     --overwrite
	    Allow program to overwrite existing target file or dataset.   Other-
	    wise,  by default, gdal errors out if the target file or dataset al-
	    ready exists.

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 suc-
     cessful execution).

EXAMPLES
   Example 1: Create contour lines from a raster elevation model
	The following example creates contour  lines  from  a  raster  elevation
	model:

	    gdal raster contour --interval 100 elevation.tif contour.shp

	This will create a shapefile named contour.shp with contour lines at 100
	meter intervals.

   Example  2: Create contour polygons from a raster elevation model with custom
     attributes and fixed levels
	The following example creates contour polygons from a  raster  elevation
	model with custom attributes and fixed levels:

	    gdal raster contour --levels MIN,100,200,MAX --polygonize --min-name MIN --max-name MAX elevation.tif contour.shp

	This  will  create  a  shapefile named contour.shp with contour polygons
	from the minimum raster value to 100, and from 100 to 200 and  from  200
	to the maximum value, and with attributes MIN, and MAX.

AUTHOR
     Alessandro Pasotti <elpaso@itopen.it>

COPYRIGHT
     1998-2026

				  Jun 05, 2026		  GDAL-RASTER-CONTOUR(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=gdal-raster-contour&sektion=1&manpath=FreeBSD+Ports+15.1.quarterly>

home | help