You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
dm-scripts/pdfcompress

73 lines
1.5 KiB
Bash

#!/bin/bash
set -euo pipefail
help_message="$(cat <<END
usage: $(basename "$0") [OPTIONS...] INPUT_PDF OUTPUT_PDF
Converts a PDF file to a series of JPEG images to reduce the quality
and then merges them back in a single pdf.
Options:
-q, --quality Set the JPEG quality (default: 75)
-h, --help Display this help message
END
)"
function show_usage() {
echo "$help_message"
exit 1
}
quality=75
while [[ $# -gt 0 ]]
do
key="$1"
case $key in
-q|--quality)
quality="$2"
shift # past argument
shift # past value
;;
-h|--help)
show_usage
;;
-*)
echo "Unknown option: $key"
show_usage
;;
*)
break
;;
esac
done
if [ -z "$1" ] || [ -z "$2" ]; then
show_usage
fi
input_file="$1"
output_file="$2"
temp_pages_dir="$(mktemp -d)"
function logf {
printf "$@"
}
logf "Rendering each page to a jpeg image (quality = $quality)\n"
pdftoppm -r 300 -jpeg -jpegopt "quality=$quality,optimize=y" -progress $input_file "$temp_pages_dir/page"
for f in "$temp_pages_dir"/page-*.jpg; do
logf "Wrapping $f into ${f/.jpg/.pdf}\n"
gs -dNOSAFER -sDEVICE=pdfwrite -o "${f/.jpg/.pdf}" /usr/share/ghostscript/lib/viewjpeg.ps -c "($f)" viewJPEG
done
logf "Merging compressed pages to a single PDF\n"
pdfunite "$temp_pages_dir"/page-*.pdf $output_file
rm -r "$temp_pages_dir"
logf "Done\n"