allewun · October 1, 2018 09:30
diff --git a/remove-watermark.sh b/remove-watermark.sh
 #!/bin/bash

 # Remove a textual watermark from a PDF file.  Requires:
 # - qpdf (brew install qpdf)
 # - pdftx (https://www.pdflabs.com/tools/pdftk-the-pdf-toolkit/pdftk_server-2.02-mac_osx-10.11-setup.pkg)
 # - coreutils (brew install coreutils)
 #
 # Tested on macOS 10.12 Sierra. 

 if [[ -z $3 ]]; then
    echo "Usage: ./remove-watermark.sh WATERMARK input.pdf output.pdf"
    exit
 fi

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

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

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

 qpdf --stream-data=uncompress "${INBOUND}" $UNCOMPRESSED
 gsed -e 's/'"${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.