pdfcompare

pdfcompare

#!/usr/bin/env bash
PDF_1="$1"
PDF_2="$2"
OUT_FILE="$3"
OUT_TMPDIR=$(mktemp -d)

cleanup() {
    rm -rf "$OUT_TMPDIR"
}
trap 'cleanup' EXIT

pdftk "$PDF_1" burst output "$OUT_TMPDIR/file_1-page_%03d.pdf" || exit 1
pdftk "$PDF_2" burst output "$OUT_TMPDIR/file_2-page_%03d.pdf" || exit 1

for f1 in $OUT_TMPDIR/file_1-page_*.pdf; do
    f2="${f1/file_1-page_/file_2-page_}"
    f_diff="${f1/file_1-page_/diff-page_}"
    f_out="${f1/file_1-page_/out-page_}"
    compare "$f1" "$f2" -quiet -compose src "$f_diff" 2> /dev/null
    pdftk "$f_diff" background "$f1" output "$f_out" || continue
done
pdftk "$OUT_TMPDIR"/out-page_*.pdf cat output "$OUT_FILE" || exit 1