gdal_sieve(1)gdal_sieve(1)NAMEgdal_sieve - Removes small raster polygons.
SYNOPSIS
gdal_sieve.py [-q] [-st threshold] [-4] [-8] [-o name=value]
srcfile [-nomask] [-mask filename] [-of format] [dstfile]
DESCRIPTION
The gdal_sieve.py script removes raster polygons smaller than a
provided threshold size (in pixels) and replaces replaces them with the
pixel value of the largest neighbour polygon. The result can be written
back to the existing raster band, or copied into a new file.
The input dataset is read as integer data which means that floating
point values are rounded to integers. Re-scaling source data may be
necessary in some cases (e.g. 32-bit floating point data with min=0 and
max=1).
Additional details on the algorithm are available in the
GDALSieveFilter() docs.
-q:
The script runs in quiet mode. The progress monitor is suppressed
and routine messages are not displayed.
-st threshold:
Set the size threshold in pixels. Only raster polygons smaller than
this size will be removed.
-o name=value:
Specify a special argument to the algorithm. Currently none are
supported.
-4:
Four connectedness should be used when determining polygons. That
is diagonal pixels are not considered directly connected. This is
the default.
-8:
Eight connectedness should be used when determining polygons. That
is diagonal pixels are considered directly connected.
srcfile
The source raster file used to identify target pixels. Only the
first band is used.
-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).
dstfile
The new file to create with the filtered result. If not provided,
the source band is updated in place.
-of format:
Select the output format. The default is GeoTIFF (GTiff). Use the
short format name.
AUTHORS
Frank Warmerdam warmerdam@pobox.com
GDAL Sun Dec 17 2017 gdal_sieve(1)