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

FreeBSD Manual Pages

  
 
  

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 dataset [required]
	  -o, --output <OUTPUT> 			       Output vector dataset (created by algorithm) [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]
	  --progress					       Display progress bar

	Options:
	  -f, --of, --format, --output-format <OUTPUT-FORMAT>  Output format
	  --co, --creation-option <KEY>=<VALUE> 	       Creation option [may be repeated]
	  --lco, --layer-creation-option <KEY>=<VALUE>	       Layer creation option [may be repeated]
	  -b, --band <BAND>				       Input band (1-based index) (default: 1)
	  -l, --nln, --layer <LAYER>			       Layer name
	  --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
	  --src-nodata <SRC-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)
	  --overwrite					       Whether overwriting existing output is allowed

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

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

     The following options are available:

   Standard options
     -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

     --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  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.

     -lco <NAME>=<VALUE>
	    Layer creation option (format specific)

     --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.

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

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

     --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.

     --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.

     --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.

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

     --src-nodata <SRCNODATA>
	    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. 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.

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

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

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

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

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

	    May be repeated.

     --if <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.

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
     1998-2025

				  Oct 29, 2025		  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