Local folder mapping in Tomcat

I am using Tomcat 7.0 and am trying to set up a local folder so that I can access images directly with a web url. Below is a snippet of config from server.xml

<Host name="localhost"  appBase="webapps" unpackWARs="true" autoDeploy="true">
    <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
           prefix="localhost_access_log." suffix=".txt"
           pattern="%h %l %u %t &quot;%r&quot; %s %b" />

    <Context path="/images" docBase="/Users/derek/Desktop/images/uploads" />
</Host>

      

        
        
        
      

    

However, when I try to access the images using the URL (http: // localhost: 8080 / images / myimage.jpg) it doesn't work. Can someone please help me?