Add a title to a image (PNG)

add-title-to-all-png.sh

#!/bin/zsh
if [[ ! -e output ]]
then
	echo creating output directory
  	mkdir output
else
	echo clearing output folder
 	rm -rf output
	echo creating output directory
  	mkdir output
fi
for file (**/*.png(ND.)) {
  echo adding label to file: $file
  width=`identify -format %w ${file}`;
  newHeight=$(($width * 0.2));
  convert -background Plum -fill white -gravity center -size ${width}x${newHeight} caption:"DEBUG" $file +swap -gravity south -composite output/$file;
}