如何读取相册封面图片?

系统默认读取的最多内容,相册封面的缩略图,如何读取封面图片?

  Array
(
    [itemid] => 16681
    [message] =>
    [image] =>
    [imagenum] => 1
    [relativetags] => Array
        (
        )

    [postip] => 219.154.84.223
    [relativeitemids] =>
    [customfieldid] => 0
    [customfieldtext] =>
    [includetags] =>
    [remoteurl] =>
    [bgmusic] =>
    [catid] => 25
    [uid] => 384
    [tid] => 0
    [username] => 如玉
    [itemtypeid] => 176
    [type] => image
    [subtype] =>
    [subject] => jiu shi
    [dateline] => 1196159362
    [lastpost] => 1196670886
    [viewnum] => 1450
    [replynum] => 1
    [trackbacknum] => 0
    [goodrate] => 0
    [badrate] => 0
    [digest] => 0
    [top] => 0
    [allowreply] => 1
    [hash] => 7574fcf818fde0bd
    [folder] => 1
    [haveattach] => 1
    [grade] => 0
    [gid] => 0
    [gdigest] => 0
    [password] =>
    [styletitle] =>
    [picid] => 0
    [subjectall] => jiu shi
    [typename] => 图片
    => [url]http://127.0.0.1/?uid-384-action-viewspace-itemid-16681
    [tags] => Array
        (
        )