Provided by: python-gdal_2.4.0+dfsg-1ubuntu3_amd64 bug


       gdal_sieve - Removes small raster polygons.

SYNOPSIS [-q] [-st threshold] [-4] [-8] [-o name=value]
                  srcfile [-nomask] [-mask filename] [-of format] [dstfile]


       The 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

       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.

           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

       -o name=value:
           Specify a special argument to the algorithm. Currently none are supported.

           Four connectedness should be used when determining polygons. That is diagonal pixels
           are not considered directly connected. This is the default.

           Eight connectedness should be used when determining polygons. That is diagonal pixels
           are considered directly connected.

           The source raster file used to identify target pixels. Only the first band is used.

           Do not use the default validity mask for the input band (such as nodata, or alpha

       -mask filename:
           Use the first band of the specified file as a validity mask (zero is invalid, non-zero
           is valid).

           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. Starting with GDAL 2.3, if not specified, the format is
           guessed from the extension (previously was GTiff). Use the short format name.


       Frank Warmerdam