<filesMatch ".(jpg|jpeg|png|gif|swf)$">
    Header set Cache-Control "max-age=604800, public"
</filesMatch>

Header merge Cache-Controll...

Cache-Control max-age=0, no-cache, no-store, must-revalidate, max-age=604800, public

Header edit Cache-control "^(?!.*max-age.*)(.*)" "max-age=604800,1"