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GDAL_POLYGONIZE(1)		      GDAL		      GDAL_POLYGONIZE(1)

NAME
     gdal_polygonize - Produces a polygon feature layer from a raster.

SYNOPSIS
	gdal_polygonize [--help] [--help-general]
			   [-8] [-o <name>=<value>]... [-nomask]
			   [-mask <filename>] <raster_file> [-b <band>]
			   [-q] [-f <ogr_format>] [-lco <name>=<value>]...
			   [-overwrite] <out_file> [<layer>] [<fieldname>]

DESCRIPTION
     This utility 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  raster  mask  may
     also be provided to determine which pixels are eligible for processing.

     The utility will create the output vector datasource if it does not already
     exist, otherwise it will try to append to an existing one.

     The utility is based on the :GDALPolygonize() function which has additional
     details on the algorithm.

     NOTE:
	gdal_polygonize  is  a	Python	utility,  and  is only available if GDAL
	Python bindings are available.

     TIP:
	Equivalent in new "gdal" command line interface:

	See gdal raster polygonize.

     --help
	    Show this help message and exit

     --help-general
	    Gives a brief usage message for the generic GDAL commandline options
	    and exit.

     -8     Use 8 connectedness. Default is 4 connectedness.

     -nomask
	    Do not use the default validity mask for the input band (such as no-
	    data, or alpha masks).

     -mask <filename>
	    Use the first band of the specified file as a validity mask (zero is
	    invalid, non-zero is valid). If not specified, the default	validity
	    mask  for  the  input  band (such as nodata, or alpha masks) will be
	    used (unless -nomask is specified)

     <raster_file>
	    The source raster file from which polygons are derived.

     -b <band>
	    The band on <raster_file> to build the polygons from. The value  can
	    also  be  set to "mask", to indicate that the mask band of the first
	    band must be used (or "mask,band_number" for the mask of a specified
	    band)

     -f <ogr_format>
	    Select the output format. If not specified, the  format  is  guessed
	    from the extension. Use the short format name

     -o <NAME>=<VALUE>
	    Added in version 3.7.

	    Polygonize option. See :GDALPolygonize() documentation.

     -lco <NAME>=<VALUE>
	    Added in version 3.7.

	    Layer creation option (format specific)

     -overwrite
	    Added in version 3.8.

	    Overwrite the output layer if it already exists.

     <out_file>
	    The destination vector file to which the polygons will be written.

     <layer>
	    The name of the layer created to hold the polygon features.

     <fieldname>
	    The name of the field to create (defaults to "DN").

     -q     The  script  runs in quiet mode.  The progress monitor is suppressed
	    and routine messages are not displayed.

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).

AUTHOR
     Frank Warmerdam <warmerdam@pobox.com>

COPYRIGHT
     1998-2026

				  Jun 05, 2026		      GDAL_POLYGONIZE(1)

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