require('Tar.php'); /* http://pear.php.net/search.php?q=tar */
$theme = 'test.thm';
$archive = & new Archive_Tar($theme);
$deskside_file = $archive -> extractInString('Theme.xml');
$image_puth = simplexml_load_string($deskside_file)-> Standby_image['Source'] or
simplexml_load_string($deskside_file)-> Desktop_image['Source'];
$image_string = $archive -> extractInString($image_puth);
header( "Content-type:image/jpeg" );
print $image_string;