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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  in-
	      stance,  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 op-
	      tions 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 cre-
	      ation options for	each format.

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

       --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>
	      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	 "con-
	      tour".

       --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
	      polygonal	contouring (-p)	mode.

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

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

       --3d   Forces the production of 3D vectors instead of 2D. Includes ele-
	      vation 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 rep-
	      resent  the  minimum  and	 maximum  values  in the raster.  When
	      --polygonize is used, the	specified values are used as bounds of
	      the generated polygons.	Mutually  exclusive  with  --interval,
	      --exp-base.

       -e, --exp-base <EXP-BASE>
	      Generate	levels on an exponential scale:	base ^ k, for k	an in-
	      teger. 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 ap-
	      propriate	 driver.  This option can be repeated several times to
	      specify several 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 cus-
       tom attributes and fixed	levels
	  The following	example	creates	contour	polygons from a	raster	eleva-
	  tion 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

				 Jul 12, 2025		GDAL-RASTER-CONTOUR(1)

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