Checks for imagemagick presence before running the script.

TODO
    Create config file to change lots of configurations (watermark position, no resizing, ....)
    Add automatic contrast calculation and watermark modification if needed

waterMark

@@ -16,6 +16,9 @@
 #composite -gravity SouthWest -geometry +5+5 -size 2000x2000 site.png foto_new.jpg test.jpg
 #convert -resize 1024 foto.jpg foto_new.jpg
 
+# Check whether imagemagick is installed
+hash identify 2>&- || { echo >&2 "imagemagick is required to use this script! Aborting."; exit 1; }
+
 IN_REPO=$1
 OUT_REPO=$2
 WATER=$3