Converts all tifs in the current directory to black and white and merges them into a single pdf

pdfify_scanned_documents.sh

#/bin/bash
EXT="tif"
# use xargs to trim whitespaces
COUNT=`ls -1 *.$EXT 2>/dev/null | wc -l | xargs`
THRESHOLD="50%"

# check if there are files of the specified extension
if [ $COUNT != 0 ]
then
echo "Converting $COUNT $EXT's to black and white and merge them to one PDF..."

# create temp dir
TEMP="$(mktemp -d)"

# convert all found images to black and white and merge them in one pdf
convert *.tif -depth 1 -colorspace Gray -threshold "$THRESHOLD" -type bilevel -colors 2 $TEMP/out_%04d.png && convert $TEMP/*.png combined.pdf

#delete temp dir
rm -rf $TEMP
 
else
	echo "No $EXT's found!"
fi