document ST_Band

git-svn-id: http://svn.osgeo.org/postgis/trunk@7312 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/doc/reference_raster.xml b/doc/reference_raster.xml
index c3e862a829c24ba2db5ead5bba0f11b416237a5d..fed4477fdac225de155e72fb9f4e934b708941b7 100644 (file)
--- a/doc/reference_raster.xml
+++ b/doc/reference_raster.xml
@@ -2055,6 +2055,82 @@ FROM (SELECT ST_MetaData(rast) As rmd
                        </refsection>
                </refentry>
                
+               <refentry id="RT_ST_Band">
+                       <refnamediv>
+                               <refname>ST_Band</refname>
+                               <refpurpose>Returns one or more bands of an existing raster as a new raster.  Useful for building new rasters from existing rasters.</refpurpose>
+                       </refnamediv>
+               
+                       <refsynopsisdiv>
+                               <funcsynopsis>
+                                  <funcprototype>
+                                  <funcprototype>
+                                       <funcdef>raster <function>ST_Band</function></funcdef>
+                                       <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
+                                       <paramdef choice='opt'><type>integer[] </type> <parameter>nbands = ARRAY[1]</parameter></paramdef>
+                                 </funcprototype>
+                                 
+                                       <funcdef>raster <function>ST_Band</function></funcdef>
+                                       <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
+                                       <paramdef><type>text </type> <parameter>nbands</parameter></paramdef>
+                                       <paramdef choice='opt'><type>character </type> <parameter>delimiter=','</parameter></paramdef>
+                                 </funcprototype>
+                                 
+                                 <funcprototype>
+                                       <funcdef>raster <function>ST_Band</function></funcdef>
+                                       <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
+                                       <paramdef><type>integer </type> <parameter>nband</parameter></paramdef>
+                                 </funcprototype>
+                               </funcsynopsis>
+                       </refsynopsisdiv>
+               
+                       <refsection>
+                               <title>Description</title>
+                               
+                               <para>Returns a single band of an existing raster as a new raster.  Useful for building new rasters from existing rasters or export of only selected
+                               bands of a raster. If no band is specified, band 1 is assumed. Used as a helper function in various functons suc as for deleting a band.</para>
+                    
+                 <para>Availability: 2.0.0</para>
+                       </refsection>
+                               
+                               <refsection>
+                                       <title>Examples</title>
+                               
+                                       <programlisting>-- Make 2 new rasters: 1 containing band 1 of dummy, second containing band 2 of dummy and then reclassified as a 2BUI
+SELECT ST_NumBands(rast1) As numb1, ST_BandPixelType(rast1) As pix1, 
+ ST_NumBands(rast2) As numb2,  ST_BandPixelType(rast2) As pix2
+FROM (
+    SELECT ST_Band(rast) As rast1, ST_Reclass(ST_Band(rast,3), '100-200):1, [200-254:2', '2BUI') As rast2
+        FROM dummy_rast
+        WHERE rid = 2) As foo;
+        
+ numb1 | pix1 | numb2 | pix2
+-------+------+-------+------
+     1 | 8BUI |     1 | 2BUI
+                                       </programlisting>
+                                       
+                                       <programlisting>-- Return bands 2 and 3. Use text to define bands
+SELECT ST_NumBands(ST_Band(rast, '2,3')) As num_bands
+    FROM dummy_rast WHERE rid=2;
+    
+num_bands
+----------
+2
+    
+-- Return bands 2 and 3. Use array to define bands
+SELECT ST_NumBands(ST_Band(rast, ARRAY[2,3])) As num_bands
+    FROM dummy_rast 
+WHERE rid=2;
+                                       </programlisting>
+                       
+                       </refsection>
+
+                       <refsection>
+                               <title>See Also</title>
+                               <para><xref linkend="RT_ST_AddBand" />, <xref linkend="RT_ST_NumBands" />, , <xref linkend="RT_ST_Reclass" /></para>
+                       </refsection>
+               </refentry>
+               
                <refentry id="RT_ST_BandMetaData">
                        <refnamediv>
                                <refname>ST_BandMetaData</refname>
@@ -4642,7 +4718,7 @@ col | row | ov1 | rv1 | ov2 | rv2 | ov3 | rv3
 
                        <refsection>
                                <title>See Also</title>
-                               <para><xref linkend="RT_ST_BandPixelType" />, <xref linkend="reclassarg" />, <xref linkend="RT_ST_Value" />/para>
+                               <para><xref linkend="RT_ST_Band" />, <xref linkend="RT_ST_BandPixelType" />,  <xref linkend="reclassarg" />, <xref linkend="RT_ST_Value" />/para>
                        </refsection>
                </refentry>
        </sect1>