完美解决织梦dedecms生成的缩略图模糊不清晰的办法

function thumb($imgurl, $width, $height, $bg = true)
 {
 global $cfg_mainsite,$cfg_multi_site;
 $thumb = eregi(“http://”,$imgurl)?str_replace($cfg_mainsite,”,$imgurl):$imgurl;
 list($thumbname,$extname) = explode(‘.’,$thumb);
 $newthumb = $thumbname.’_’.$width.’_’.$height.’.’.$extname;
 if(!$thumbname || !$extname || !file_exists(DEDEROOT.$thumb)) return $imgurl;
 if(!file_exists(DEDEROOT.$newthumb))
 {
 include_once DEDEINC.’/image.func.php’;
if($bg==true)
 {
 ImageResizeNew(DEDEROOT.$thumb, $width, $height, DEDEROOT.$newthumb);
 }
 else
 {
 ImageResize(DEDEROOT.$thumb, $width, $height, DEDEROOT.$newthumb);
 }
 }
 return $cfg_multi_site==’Y'?$cfg_mainsite.$newthumb:$newthumb;
 }