clean_pdf.sh

#!/usr/bin/env bash

set -e

if [ "$#" -lt 2 ]; then
  echo "Usage: $0 input.pdf output.pdf"
  exit 1
fi

INPUT_PDF=$1
OUTPUT_PDF=$2

echo "Extracting JPG's from PDF"
pdfimages -all $INPUT_PDF extracted

echo "Cleaning JPG's"
convert extracted-*.jpg -colorspace Gray -normalize -level 20%,80% -brightness-contrast 10x40 -set filename:fn 'clean-%[basename]' '%[filename:fn].jpg'

echo "Creating output PDF..."
convert clean-*.jpg $OUTPUT_PDF
echo "...done"

echo "Cleaning temporary files..."
rm extracted-*.jpg
rm clean-extracted-*.jpg
echo "All done :)"