diff --git a/functions/image.xml b/functions/image.xml
index 825f27858d..9178318368 100644
--- a/functions/image.xml
+++ b/functions/image.xml
@@ -11,6 +11,20 @@
     url="&url.gd;">&url.gd;</ulink>) you will also be able to create
     and manipulate images.
    </simpara>
+   <simpara>
+   The format of images you are able to manipulate depend on the
+   version of gd you install, and any other libraries gd might need
+   to access those image formats. Versions of gd older than gd-1.6
+   support gif format images, and do not support png, where versions
+   greater than gd-1.6 support png, not gif.
+   </simpara>
+   <simpara>
+   In order to read and write images in jpeg format, you will need to
+   obatin and install jpeg-6b (available at
+   <ulink url="&url.jpeg;">&url.gd;</ulink>), and then recompile gd to
+   make use of jpeg-6b. You will also have to compile PHP with
+   <option role="configure">--with-jpeg-dir=/path/to/jpeg-6b</option>.
+   </simpara>
   </partintro>
 
   <refentry id="function.getimagesize">