Normalize PDF scans with handwritten notes and color markings

normalize.sh

#!/usr/bin/env zsh

set -x
set -e

filename=$(basename -- "$1")
name="${filename%.*}"

# from https://poppler.freedesktop.org/
pdfimages -j -p $1 $name

for image in `find -type f -name $name-\*.jpg`;
do
    imageName="${image%.*}"
    echo $image
    echo $imageName
    # convert from https://imagemagick.org
    # https://imagemagick.org/script/command-line-options.php
    convert -normalize -modulate 100,250,100 $image $imageName.modified.jpg
    rm $image
done

# https://gitlab.mister-muffin.de/josch/img2pdf
img2pdf $name-*.modified.jpg -o $name.processed.pdf
rm $name-*.modified.jpg