start documenting ST_DumpAsPolygons. Will provide examples once get it to stop crash...

git-svn-id: http://svn.osgeo.org/postgis/trunk@5530 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/doc/reference_wktraster.xml b/doc/reference_wktraster.xml
index 3ea596ca2e08f40b72e85b424d3fc2f0147ea457..e14f1e85be73af9ff449919a0d804c44800d1837 100644 (file)
--- a/doc/reference_wktraster.xml
+++ b/doc/reference_wktraster.xml
@@ -351,7 +351,7 @@ VALUES (1,
          <refsection>
                <title>See Also</title>
 
-               <para><xref linkend="RT_AddRasterColumn"/>, <xref linkend="RT_DropGeometryColumn"/></para>
+               <para><xref linkend="RT_AddRasterColumn"/>, <xref linkend="RT_DropRasterColumn"/></para>
          </refsection>
        </refentry>
 
@@ -1482,6 +1482,53 @@ FROM (SELECT ST_SetRotation(rast,0.1,0.1) As rast
                                <para><xref linkend="RT_ST_Envelope" />, <xref linkend="ST_ConvexHull" />, <xref linkend="ST_AsText" /></para>
                        </refsection>
                </refentry>
+               
+               <refentry id="RT_ST_DumpAsPolygons">
+                 <refnamediv>
+                       <refname>ST_DumpAsPolygons</refname>
+                       <refpurpose>Returns a set of geomval (geom,val) rows, from a given raster band.  If no band number is specified, band num defaults to 1.</refpurpose>
+                 </refnamediv>
+       
+                 <refsynopsisdiv>
+                       <funcsynopsis>
+                         <funcprototype>
+                               <funcdef>geomval[] <function>ST_DumpAsPolygons</function></funcdef>
+                               <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
+                         </funcprototype>
+                         
+                         <funcprototype>
+                               <funcdef>geomval[] <function>ST_DumpAsPolygons</function></funcdef>
+                               <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
+                               <paramdef><type>integer </type> <parameter>band_num</parameter></paramdef>
+                         </funcprototype>
+                       </funcsynopsis>
+                 </refsynopsisdiv>
+       
+                 <refsection>
+                       <title>Description</title>
+                               <para>This is a set-returning function (SRF). It returns a set of
+                               geomval rows, formed by a geometry (geom) and a pixel band value (val). 
+                               Each polygon is the union of all pixels for that band that have the same pixel value denoted by val</para>
+       
+                               <para>ST_DumpAsPolygon is useful for polygonizing rasters. It is the
+                               reverse of a GROUP BY in that it creates new rows. For example it
+                               can be used to expand a single raster into multiple POLYGONS/MULTIPOLYGONS.</para>
+       
+                               <para>Availability: Requires GDAL 1.6 or higher.</para>
+                               <note><para>Still under development and testing.</para></note>
+                 </refsection>
+       
+                 <refsection>
+                       <title>Examples</title>
+               <programlisting><!-- TODO: need examples --> 
+                       Forthcoming
+               </programlisting>
+                 </refsection>
+                 <refsection>
+                       <title>See Also</title>
+                       <para><xref linkend="RT_ST_Value" /></para>
+                 </refsection>
+               </refentry>
        </sect1>
        
        <sect1 id="RT_Operators">