Trim images with too much whitespace and then add a border of a set value

prep_image_files_with_borders.sh

#!/bin/bash
#based on code found here: 
#http://jcornuz.wordpress.com/2007/10/26/imagemagick-and-bash-batch-power/
#This script takes an image with a lot of extra border, trims it down 
#and then re-adds a 20 pixel border evenly around the edge.
#REQUIRES IMAGEMAGICK AND GHOSTSCRIPT

#the tiles will be put in a directory called...
MYDIR="PROCESSED"

#If the destination folder doesn't exist, make it. 
if [ ! -d ./${MYDIR} ]; then mkdir ./${MYDIR}; fi

# processes all pngs
#if there are png files found, then for each of them 
if ls | grep png; then for p in *.png; do
	echo "Processing $p"
	#Trim it, then add a border, 
	#then save it to a new directory with an
	#appended file name. 
	convert \( $p -fuzz 1% -trim \) \
		-bordercolor white -border 20x20 +repage \
		./PROCESSED/${p/.png}_clean.png
done
fi

#process all the PDFs
#if there are pdf files found, then for each of them 
if ls | grep pdf; then for d in *.pdf; do
        echo "Processing $d"
        #Open it at an image density of 250px/in,
        #trim it, then add a border. 
	#Save it to a new directory with an
	#appended file name. 
	convert \( \( -density 250 $d \) -fuzz 1% -trim \) \
		-bordercolor white -border 20x20 +repage \
		./PROCESSED/${d/.pdf}_clean.png
done
fi