1. Order Allow,Deny
  2. <FilesMatch "^[^.]+\.(?:[Jj][Pp][Ee]?[Gg]|[Pp][Nn][Gg]|[Gg][Ii][Ff]|[Pp][Dd][Ff])$">
  3. Allow from all
  4. </FilesMatch>
  5.  
  6. or:
  7.  
  8. Order Allow,Deny
  9. <FilesMatch "^[^.]+\.(?i:jpe?g|png|gif|pdf)$">
  10. Allow from all
  11. </FilesMatch>