</listitem>
<listitem>
<para>
- <varname>nbands</varname> is an array of bands to export (note that max is 3 for PNG) and the order of the bands is RGB. e.g ARRAY[3,2,1] means map band 3 to Red, band 2 to green and band 1 to blue
+ <varname>nbands</varname> is an array of bands to export (note that max is 4 for PNG) and the order of the bands is RGBA. e.g ARRAY[3,2,1] means map band 3 to Red, band 2 to green and band 1 to blue
</para>
</listitem>
<listitem>
<para>Passing a <type>regprodedure</type> argument to a SQL function requires the full function signature to be passed, then cast to a <type>regprocedure</type> type. To pass the above example PL/pgSQL function as an argument, the SQL for the argument is:<programlisting>'simple_function(double precision, double precision, integer[], text[])'::regprocedure</programlisting>Note that the argument contains the name of the function, the types of the function arguments, quotes around the name and argument types, and a cast to a <type>regprocedure</type>.
</para>
- <para>The third argument to the <varname>tworastuserfunc</varname> is a <type>variadic text</type> array. All trailing text arguments to any <xref linkend="RT_ST_MapAlgebraFct2" /> call are passed through to the specified <varname>tworastuserfunc</varname>, and are contained in the <varname>userargs</varname> argument.
+ <para>The fourst argument to the <varname>tworastuserfunc</varname> is a <type>variadic text</type> array. All trailing text arguments to any <xref linkend="RT_ST_MapAlgebraFct2" /> call are passed through to the specified <varname>tworastuserfunc</varname>, and are contained in the <varname>userargs</varname> argument.
</para>
<note>