The 1.0 SLD specification indicates that the tag is optional:
<xs:element ref=“sld:Size” minOccurs=“0”/>
However, if I do not include the tag my graphic seems incredibly small,
as if the Size defaults to 1 pixel or something.
I have a test graphic with some text on it that has a width of 136 and a height of 13.
(http://maps.massgis.state.ma.us/images/short_wide.gif)
If the GetMap request below is posted to http://64.119.128.70/geoserver/wms
the graphic looks correct, because I specify the height of the graphic.
(The SLD spec also says that the height should be used:
The Size element gives the absolute size of the graphic in pixels encoded
as a floatingpoint number. This element is also used in other contexts than
graphic size and pixel units are still used even for font size. The default size
for an object is context-dependent. Negative values are not allowed. The
default size of an image format (such as GIF) is the inherent size of the image.
The default size of a format without an inherent size (such as SVG) is defined
to be 16 pixels in height and the corresponding aspect in width. If a size is
specified, the height of the graphic will be scaled to that size and the corresponding
aspect will be used for the width.)
However, if I delete this line: 13.0
from my request I get a tiny graphic. According to the SLD spec,
“The default size of an image format (such as GIF) is the inherent size
of the image”, shouldn’t the graphic’s height be used?
<wms:GetMap service=“WMS” version=“1.3.0” xmlns:gml=“http://www.opengis.net/gml”
xmlns:ows=“http://www.opengis.net/ows” xmlns:sld=“http://www.opengis.net/sld”
xmlns:wms=“http://www.opengis.net/ows” xmlns:xlink=“http://www.w3.org/1999/xlink”
xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance”
xsi:schemaLocation=“http://www.opengis.net/ows http://64.119.128.70/geoserver/schemas/sld/GetMap.xsd”>
<sld:StyledLayerDescriptor version=“1.0.0”>
sld:NamedLayer
sld:Namemassgis:GISDATA.ICERINKS_PT</sld:Name>
SHAPE
image/gif
13.0
Aleda Freeman
MassGIS
Office of Geographic and Environmental Information
251 Causeway St. 5th floor
Boston, MA 02114
phone: 617-626-1193
fax: 617-626-1249
http://www.mass.gov/mgis - MassGIS
http://lyceum.massgis.state.ma.us - Webservices Wiki
http://maps.massgis.state.ma.us/biodiversity - EOEEA Biodiversity Days