Remove a textual watermark from a PDF file.

remove-watermark.sh

#!/bin/bash

# Remove a textual watermark from a PDF file.  Requires qpdf and pdftx
# to work correctly.  The correct usage is
#
# remove-watermark WATERMARK "Your Input File.pdf" "Your Output File.pdf"

WATERMARK=$1
INBOUND=$2
OUTBOUND=$3

UNCOMPRESSED=`mktemp --dry-run 'uncompressed-XXXXXXXXXX.pdf'`
FIXED=`mktemp --dry-run 'fixed-XXXXXXXXXX.pdf'`
UNMARKED=`mktemp --dry-run 'unmarked-XXXXXXXXXX.pdf'`

WATERMARKLEN=${#WATERMARK}
BLANKS=`printf %${WATERMARKLEN}s`

qpdf --stream-data=uncompress "$INBOUND" $UNCOMPRESSED
sed -e 's/\[($WATERMARK)\]/[($BLANKS)]/g' < $UNCOMPRESSED > $FIXED
pdftk $FIXED output $UNMARKED
qpdf --stream-data=compress $UNMARKED "$OUTBOUND"
rm $UNCOMPRESSED $FIXED $UNMARKED

# NO WARRANTY
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Hi Elf,

thanks for your great tool. Can I also remove a multiline watermark?

E.g. at https://www.peterlang.com/downloadpdf/title/17680.pdf

Kind regards

Thanks for this. Wrote a variant since I was getting sed: RE error: illegal byte sequence and pdftk doesn't work on newer versions of OS X: https://gist.github.com/convexset/28abc9c7be261954507ac705cbf64099