nginx404_for_pictures,base

nginx.conf

server {
  listen       3000;
  server_name  host;
  root /path/to/project/..;
  #passenger_enabled on;
  #rails_env development;

  location ~* \.(js|css|gif|png|bmp|jpeg|jpg|swf)$  {
    access_log    off;
    log_not_found off;
    expires       max;

    error_page 404 = (~ : root)/path/to/default.jpg;
    break;
  }
}