File directory token - image field - node author
Have a look at this issue that explains why you cannot use node tokens in Views: https://www.drupal.org/node/1788414


  This is a limitation of Drupal core - it does not provide any node
  context for token replacement aside from the global tokens that are
  available. You will need a module like
  http://drupal.org/project/filefield_paths in order to use node tokens
  in the file upload directory tokens.


The File (Field) Paths module provides this functionality:


  The File (Field) Paths module extends the default functionality of
  Drupal's core File module, Image module and many other File upload
  modules, by adding the ability to use entity based tokens in
  destination paths and file names.
  
  In simple terms, File (Field) Paths allows you to automatically sort
  and rename your uploaded files using token based replacement patterns
  to maintain a nice clean filesystem.


That should allow you to use the node:author token.