GDAL_POLYGONIZE(1) GDAL GDAL_POLYGONIZE(1)
NAME
gdal_polygonize - Produces a polygon feature layer from a raster.
SYNOPSIS
gdal_polygonize.py [-8] [-nomask] [-mask filename] <raster_file> [-b band]
[-q] [-f ogr_format] <out_file> [layer] [fieldname]
DESCRIPTION
This utility creates vector polygons for all connected regions of pix-
els in the raster sharing a common pixel value. Each polygon is cre-
ated 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 al-
ready exist, defaulting to GML format.
The utility is based on the :GDALPolygonize() function which has addi-
tional details on the algorithm.
-8 Use 8 connectedness. Default is 4 connectedness.
-nomask
Do not use the default validity mask for the input band (such as
nodata, 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 de-
fault 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. Starting
with GDAL 2.2, 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. Starting with GDAL 2.3, if not speci-
fied, the format is guessed from the extension (previously was
GML). Use the short format name
<out_file>
The destination vector file to which the polygons will be writ-
ten.
<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 sup-
pressed and routine messages are not displayed.
AUTHOR
Frank Warmerdam <warmerdam@pobox.com>
COPYRIGHT
1998-2021
Dec 27, 2021 GDAL_POLYGONIZE(1)
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