Rename and move images according to date

My simple import-images.sh script that I use to shift files into my (ownCloud-backed) archiving system:

#!/bin/bash

if [ ! -d "$1" ]; then
  echo "Error: first parameter must be a directory" >&2
  echo "Usage: "$(basename $0)" 

<dir>
  "
    echo "       where 
  
  <dir>
    is an existing directory from which to import images"
      exit 1
    fi
    
    DEST=$HOME/photos
    exiftool '-FileName<DateTimeOriginal' -d $DEST"/%Y/%m_%b/%d/%Y-%m-%d_%H%M%%+c.%%e" "$1"