.htaccess图像重定向

I've written a PHP class to add a watermark to an image, it works great when accessed via URL directly. I would like to "redirect" every image to my URL like so:

http://www.mysite.com/img.jpg

to this

http://www.mysite.com/watermark/watermark.php?image=http://www.mysite.com/img.jpg

Basically what I want is to pass the src attribute specified in the HTML to the image variable. I'm currently struggling with my .htaccess file and I can't get it working, here it is:

Options +FollowSymLinks
RewriteEngine On
RewriteRule ^([^_].*\.(gif|jpg|png))$ /watermark/watermark.php?image=$1 [L]

Looking forward to your replies and thanks in advance!

Try this:

RewriteEngine On
RewriteBase /
RewriteRule ^(.*)\.(jpg|png|jpeg|gif)$ watermark/watermark.php?image=$1.$2 [NC,L]

Try adding -MultiViews to your options line, so it reads as:

Options +FollowSymLinks -MultiViews