diff --git a/wp b/wp
index cd1a714..5cca878 100755
--- a/wp
+++ b/wp
@@ -14,19 +14,16 @@ function main {
   done
   DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
   K_MEANS=16
-  WALLPAPER_DIR=${WALLPAPER_DIR:-~/.wallpapers/}
+  WALLPAPER_DIR=${WALLPAPER_DIR:-~/.wallpapers}
+  # Get canonical path
+  WALLPAPER_DIR="$(readlink -f "$WALLPAPER_DIR")"
 
-  while test $# -gt 0; do
+  if test $# -gt 0; then
       case "$1" in
-          usage | -h | --help)
+          usage | -h | --help | help)
               shift
               usage
               ;;
-          n | -n)
-              shift
-              K_MEANS=$1
-              shift
-              ;;
           add | -a | --add)
               shift
               add $*
@@ -35,7 +32,7 @@ function main {
               shift
               remove $*
               ;;
-          change)
+          change | next)
               shift
               change $*
               ;;
@@ -56,11 +53,12 @@ function main {
               slideshow $*
               ;;
           *)
-              shift
-              indent "$1 is not a recognised directive"
+              indent "$1 is not a recognized directive"
               ;;
       esac
-  done
+  else
+      usage
+  fi
 }
 
 #:: Prety print function
@@ -86,6 +84,11 @@ function add {
     exit 1
   fi
 
+  if [ '-n' = $1 ]; then
+      K_MEANS=$2
+      shift 2
+  fi
+
   files=$*
 
   for file in $files; do
@@ -99,7 +102,7 @@ function add {
   cd $WALLPAPER_DIR
 
   for file in $*; do
-    echo ":: Generating .$file.colors and .$file.Xres in $PWD"
+    echo ":: Generating .$file.colors and .$file.Xres in $PWD with $K_MEANS colors"
     python2 $DIR/py/color_detect.py $file $K_MEANS
   done
 }
@@ -117,14 +120,14 @@ function remove {
   for file in $*; do
     indent "Removing $file"
     rm ${WALLPAPER_DIR}/${file}
-    rm ${WALLPAPER_DIR}/.${file}.{colors,Xres}
+    rm ${WALLPAPER_DIR}/.${file}.{colors,Xres,sample.png}
   done
 }
 
 function change {
   #:: Select a random background from WALLPAPER_DIR, or use the passed background
   if [ -z $1 ]; then
-    background=$(find $WALLPAPER_DIR -type f \( -name '*.jpg' -o -name '*.png' \) | shuf -n1)
+      background=$(find $WALLPAPER_DIR -type f | grep -P "^((?!sample).)*\.(jpg|png)\$" | shuf -n1)
   else
     background=$WALLPAPER_DIR/$1
 
@@ -186,7 +189,7 @@ function get_current {
 }
 
 function set_current {
-  ln -sf $1  $WALLPAPER_DIR/.current
+  ln -sf $1 $WALLPAPER_DIR/.current
 }
 
 function list {
@@ -231,18 +234,17 @@ function usage {
   printf "%b" "  $0 [action] [options]
 
 Actions
-- usage:                Print this help message.
-- n [number]   :        Number of colors to gather.
-- add [file]...:        Add file, or files, to the wallpaper database.
-- rm  [file]...:        Remove file, or files, from the wallpaper database.
-- change [file]:        Set the wallpaper to file, or a random wallpaper
-                        from the wallpaper database.
-- slideshow [cmd file]: Rotate through wallpapers, optionally
-                        running cmd each time and using only
-                        wallpapers listed in the file.
-- current:              List the current background
-- ls:                   List all wallpapers in the database.
-- colors:               Display the current set of colors.
+- usage:                                  Print this help message.
+- add [-n [number of colors]] [file]...:  Add file, or files, to the wallpaper database.
+- rm  [file]...:                          Remove file, or files, from the wallpaper database.
+- change [file]:                          Set the wallpaper to file, or a random wallpaper
+                                          from the wallpaper database.
+- slideshow [cmd file]:                   Rotate through wallpapers, optionally
+                                          running cmd each time and using only
+                                          wallpapers listed in the file.
+- current:                                List the current background
+- ls:                                     List all wallpapers in the database.
+- colors:                                 Display the current set of colors.
 "
 }