man gdal_contour (Commandes) - builds vector contour lines from a raster elevation model

NAME

gdal_contour - builds vector contour lines from a raster elevation model

SYNOPSIS

Usage: gdal_contour [-b <band>] [-a <attribute_name>] [-3d] [-inodata]
                    [-snodata n] [-f <formatname>] [-i <interval>]
                    [-off <offset>] [-fl <level> <level>...]
                    <src_filename> <dst_filename> <interval>

DESCRIPTION

This program generates a vector contour file from the input raster elevation model (DEM).

-s_srs srs def:
source spatial reference set. The coordinate systems that can be passed are anything supported by the OGRSpatialReference.SetFromUserInput() call, which includes EPSG PCS and GCSes (ie. EPSG:4296), PROJ.4 declarations (as above), or the name of a .prf file containing well known text. </dl

-b band:
picks a particular band to get the DEM from. Defaults to band 1.

-a name:
provides a name for the attribute in which to put the elevation. If not provided no elevation attribute is attached.
-3d:
Force production of 3D vectors instead of 2D. Includes elevation at every vertex.

-inodata:
Ignore any nodata value implied in the dataset - treat all values as valid.

-snodata value:
Input pixel value to treat as 'nodata'.

-f format:
create output in a particular format, default is shapefiles.

-i interval:
elevation interval between contours.

-off offset:
Offset from zero relative to which to interpret intervals.

-fl level:
Name one or more 'fixed levels' to extract.

EXAMPLE

This would create 10meter contours from the DEM data in dem.tif and produce a shapefile in contour.shp/shx/dbf with the contour elevations in the 'elev' attribute. 

gdal_contour -a elev dem.tif contour.shp 10.0

AUTHORS

Frank Warmerdam <warmerdam@pobox.com> Silke Reimer <silke@intevation.de>