Landscape images within a portrait DocBook document.

Hi,

We want create a DocBook document in a portrait format.
Some graphics (UML graphics) must be rendered in a landscape format because they are too large.
How is it possible to display the graphics in a lanscape format within a document in a portrait format?

The most valuable link I found on the internet is this: http://www.sagehill.net/docbookxsl/LandscapeImage.html
Is it another solution?

We use DocBook in the following environment:

$ mvn -version
Apache Maven 2.2.0 (r788681; 2009-06-26 15:04:01+0200)
Java version: 1.6.0_16
Java home: C:\Programme\Java\jdk1.6.0_16\jre
Default locale: de_CH, platform encoding: UTF-8
OS name: "windows xp" version: "5.1" arch: "x86" Family: "windows"

        <plugin>
          <groupId>com.agilejava.docbkx</groupId>
          <artifactId>docbkx-maven-plugin</artifactId>
          <version>2.0.10</version>
          <dependencies>

            <dependency>
              <groupId>org.docbook</groupId>
              <artifactId>docbook-xml</artifactId>
              <version>4.4</version>
              <scope>runtime</scope>
            </dependency>

          </dependencies>
        </plugin>

Thank you for your help
Jean-Claude