How to do .htaccess redirect and HTTP cache for static images in a no-cookie subdomain

Question

We want to do redirects for our site photos from domain.com/images/ to a no-cookie img.domain.com. Currently, we have images directory in public_html, URLs are:

http://domain.com/images/subfolder-1/title-of-the-image.jpg
http://domain.com/images/subfolder-2/title-of-the-image.jpeg
http://domain.com/images/subfolder-3/title-of-the-image.gif
http://domain.com/images/subfolder-4/title-of-the-image.png

In cPanel, img.domain.com has been set to publi_html/images

We tried to unset cookie and redirect via htaccss. Yet, it does not work.

In htaccess,

AddDefaultCharset UTF-8

## Re-directing
Options +FollowSymlinks -MultiViews
RewriteEngine On
RewriteCond %{HTTP_HOST} !^(www\.)?images\. [NC]
RewriteRule ^(.*)$ http://www.img.domain.com/$1 [L,NE,R=301]

# Expire headers
<IfModule mod_expires.c>
    ExpiresActive On
    ExpiresDefault "access plus 29030400 seconds"
    ExpiresByType image/x-icon "access plus 29030400 seconds"
    ExpiresByType image/jpeg "access plus 29030400 seconds"
    ExpiresByType image/jpg "access plus 29030400 seconds"
    ExpiresByType image/png "access plus 29030400 seconds"
    ExpiresByType image/gif "access plus 29030400 seconds"
</IfModule>

# Headers
<IfModule mod_headers.c>
    <FilesMatch "\\.(ico|jpe?g|png|gif|swf)$">
        Header unset Cookie
        Header unset Set-Cookie
        Header set Cache-Control "max-age=29030400, public"
        Header set Last-Modified "Mon, 24 Mar 2014 00:00:00 GMT"
    </FilesMatch>
</IfModule>

We wonder what to keep/add/change in the above .htaccess code, which is located inside images directory, or if there are better ways. Thanks!

Answer 1

Add this rule just below RewriteEngine On in /images/.htaccess file:

RewriteCond %{HTTP_HOST} !^(www\.)?images\. [NC]
RewriteRule ^(.*)$ http://www.images.domain.com/$1 [L,NE,R=301]