Acccessing Image in a blogs using PHP rss reader

I am trying to build a portal in PHP5.I want to access the 开发者_StackOverflow社区images in a given blog URL, through an RSS Reader.

I am able to access the content of the blog,but I am not able to get the images.

To access the url of an image you must look for image element within the item element.

 <image>
    <url>http://www.w3schools.com/images/logo.gif</url>
    <title>W3Schools.com</title>
    <link>http://www.w3schools.com</link>
  </image>

Below is the the full example:

<channel>
  <title>W3Schools Home Page</title>
  <link>http://www.w3schools.com</link>
  <description>Free web building tutorials</description>
  <image>
    <url>http://www.w3schools.com/images/logo.gif</url>
    <title>W3Schools.com</title>
    <link>http://www.w3schools.com</link>
  </image>
  <item>
    <title>RSS Tutorial</title>
    <link>http://www.w3schools.com/rss</link>
    <description>New RSS tutorial on W3Schools</description>
  </item>
</channel>

If the RSS Feed doesn't contain an Image element then the RSS provider will not be sending related images within the RSS.