<?
$s =<<<HTMLCODE
<img src="이미지">
<area shape=RECT target=_blank coords=4,5,129,45 href="http://www.naver.com">
<area shape=RECT target=_blank coords=430,69,582,106 href="http://www.gmail.com/ ">
<area shape=RECT target=_blank coords=17,328,200,411 href=" http://www.naver.com ">
<area shape=RECT target=_blank coords=19,456,477,496 href=" http://www.naver.com">
<area shape=RECT target=_blank coords=18,500,574,534 href=" http://www.naver.com">
<area shape=RECT target=_blank coords=17,589,201,666 href="http://www.naver.com">
<area shape=RECT target=_blank coords=209,586,388,667 href="http://www.naver.com ">
<area shape=RECT target=_blank coords=401,585,594,669 href=" http://www.naver.com">
HTMLCODE;

$src = array("/=\"\s/", "/\s\"\>/");
$tar = array("=\"", "\">");
$s = preg_replace($src, $tar, $s);
?>
<textarea rows=10 cols=100><?=$s?></textarea>

http://phpschool.com/gnuboard4/bbs/board.php?bo_table=qna_function&wr_id=241172&sca=&sfl=mb_id&stx=kagla&sop=and

이거 같은 경우는 항상 "로 쌓여있다는 가정하에 본다면

e 를 사용하여 처리하면 될것같습니다.

<?
$s =<<<HTMLCODE
<img src="이미지">
<area shape=RECT target=_blank coords=4,5,129,45 href="http://www.naver.com">
<area shape=RECT target=_blank coords=430,69,582,106 href="http://www.gmail.com/ ">
<area shape=RECT target=_blank coords=17,328,200,411 href=" http://www.naver.com ">
<area shape=RECT target=_blank coords=19,456,477,496 href=" http://www.naver.com">
<area shape=RECT target=_blank coords=18,500,574,534 href=" http://www.naver.com">
<area shape=RECT target=_blank coords=17,589,201,666 href="http://www.naver.com">
<area shape=RECT target=_blank coords=209,586,388,667 href="http://www.naver.com ">
<area shape=RECT target=_blank coords=401,585,594,669 href=" http://www.naver.com">
HTMLCODE;



$s = preg_replace("`href\s*=\s*\"(.+)\"`iUe", "'href=\"'.trim('\\1').'\"'", $s);
?>
<textarea rows=10 cols=100><?=$s?></textarea>

$out1 = preg_replace("/(<area[^>]*href=[\"']?)\s*([^>\"'\s]+)\s*([\"']?[^>]*>)/i", "\${1}\${2}\${3}", $s);

echo "<xmp>";
print_r($out1);
echo "</xmp>";