need regular expression to match image file, please help.

$re = '/<img.+src=[\'"]([^\'"]+)[\'"].*>/i';

I am using this regular expression to match all image files, now i need to filter based on domain name. for example, i want to get all images contain "yahoo.com".

http://yahoo.com/image/1.jpg

I rewrote this RE, but its working. please help me out.
$re = '/<img.+src=[\'"]([^\'"]+)(yahoo.com)([^\'"]+)[\'"].*>/i';

 

first, try regexpal
second:
$re = '/<img\s+src=[\'"]([^\'"]+)(yahoo\.com)([^\'"]+)[\'"].*?>/i';