gdal-raster-polygonize - Create a polygon feature dataset from a raster band
NAME SYNOPSIS DESCRIPTION Standard options Advanced options EXAMPLES Example 1: Create a shapefile with polygons for the connected regions ofband 1 of the input GeoTIFF. AUTHOR COPYRIGHTNAME
gdal-raster-polygonize − Create a polygon feature dataset from a raster band
Added in version 3.11.
SYNOPSIS
Usage: gdal raster polygonize [OPTIONS] <INPUT> <OUTPUT>
Create a polygon feature dataset from a raster band.
Positional
arguments:
−i, −−input <INPUT> Input raster
dataset [required]
−o, −−output <OUTPUT> Output vector
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]
−−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]
−−overwrite Whether overwriting existing output
is allowed
−−update Whether to open existing dataset in
update mode
−−overwrite−layer Whether overwriting
existing layer is allowed
−−append Whether appending to existing layer is
allowed
−b, −−band <BAND> Input band
(1−based index) (default: 1)
−l, −−nln, −−layer
<LAYER> Layer name (default: polygonize)
−−attribute−name
<ATTRIBUTE−NAME> Name of the field with the
pixel value (default: DN)
−c, −−connect−diagonal−pixels
Consider diagonal pixels as connected
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 polygonize creates vector polygons for all connected regions of pixels in the raster sharing a common pixel value. Each polygon is created with an attribute indicating the pixel value of that polygon. A mask (either explicit, or implicit through nodata value or band) associated to the selected band can be used to determine the which pixels should be included in the processing.
The utility can create the output vector datasource if it does not already exist, otherwise it may append to an existing one.
The utility is based on the :GDALPolygonize() function which has additional details on the algorithm.
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 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.
−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.
−−update
Whether the output dataset must be opened in update mode. Implies that it already exists.
−−overwrite−layer
Whether overwriting the existing output vector layer is allowed.
−−append
Whether appending features to the existing output vector layer is allowed
−b, −−band <BAND>
Picks a particular band to polygonize. Defaults to band 1.
−l, −−nln, −−layer <LAYER>
Provides a name for the output vector layer. Defaults to "polygonize".
−−attribute−name <ELEVATION−NAME>
The name of the field to create (defaults to "DN").
−c, −−connect−diagonal−pixels
Consider diagonal pixels (pixels at the corners) as connected. The default behavior is to only consider pixels that are touching the edges as connected, which is the same as 4−connectivity. When this option is selected, the algorithm will also consider pixels at the corners as connected, which is the same as 8−connectivity.
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 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 a shapefile with polygons for the connected regions ofband 1 of the input GeoTIFF.
gdal raster polygonize input.tif polygonize.shp
AUTHOR
Even Rouault <[email protected]>
COPYRIGHT
1998-2025