I've got a double-side-printed multipage document to scan with a linear bulk scanner. So, as the result I get 2 PDF files: one containing all odd pages and the second containing all even pages. I need to merge them the natural way:
1. <- 1.1. (odd.pdf page 1 to result.pdf page 1)
2. <- 2.1. (even.pdf page 1 to result.pdf page 2)
3. <- 1.2. (odd.pdf page 2 to result.pdf page 3)
4. <- 2.2. (even.pdf page 2 to result.pdf page 4)
etc.
pdftk has a shuffle command which collates pages:
pdftk A=odd.pdf B=even.pdf shuffle A B output collated.pdf
See the pdfseparate and pdfunite commands from poppler-utils. The first to separate the pages from each document into individual files, and the second to merge them in the order you want in a new document.
Also note that since scanners give you raster images anyway (which some like yours can concatenate into a PDF files), maybe you can configure it to output images (png, tiff...) instead, and do the concatenation into a PDF yourself with ImageMagick.
Just a bash quick shot using pdfjam:
Build an array of input arguments:
for k in $(seq 1 ${N_PAGES}); do
PAGES+=(odd.pdf);
PAGES+=($k);
PAGES+=(even.pdf);
PAGES+=($k);
done
This should allow you to use it as input list for pdfjoin:
pdfjoin ${PAGES[@]} --outfile shuffled.pdf
I came up with this script which is based on the other answers.
In my case I scan the front pages and the back pages into the same file, so I first need to split the file in half and then shuffle it with pdftk:
#!/bin/bash
## Assume:
# We have
#
# 1 3 5 7 8 6 4 2
# and want it in
# 1 2 3 4 5 6 7 8
NO_OF_PAGES=`pdftk "$1" dump_data | grep NumberOfPages | cut -d " " -f 2`
HALF=`echo $(( $NO_OF_PAGES / 2 ))`
FRONTSIDES=1-$HALF
BACKSIDES=$(( $HALF + 1 ))-$NO_OF_PAGES
pdftk "$1" cat $FRONTSIDES output /tmp/$$fronts.pdf
pdftk "$1" cat $BACKSIDES output /tmp/$$backs.pdf
pdftk A=/tmp/$$fronts.pdf B=/tmp/$$backs.pdf shuffle A Bend-1 output "$1.remixed.pdf"
I came across this bash script doing this, it assumes you scanned the even pages in reverse order, but you can change this removing the -r in the line saying evenpages=($(ls "$evenbase-$key-"* | sort -r)) (this is line 46)
#!/bin/bash
# Copyright Fabien André <[email protected]>
# Distributed under the MIT license
# This script interleaves pages from two distinct PDF files and produces an
# output PDF file. The odd pages are taken from a first PDF file and the even
# pages are taken from a second PDF file passed respectively as first and second
# argument.
# The first two pages of the output file are the first page of the
# odd pages PDF file and the *last* page of the even pages PDF file. The two
# following pages are the second page of the odd pages PDF file and the
# second to last page of the even pages PDF file and so on.
#
# This is useful if you have two-sided documents scanned each side on a
# different file as it can happen when using a one-sided Automatic Document
# Feeder (ADF)
#
# It does a similar job to :
# https://github.com/weltonrodrigo/pdfapi2/blob/46434ab3f108902db2bc49bcf06f66544688f553/contrib/pdf-interleave.pl
# but only requires bash (> 4.0) and poppler utils.
# Print usage/help message
function usage {
echo "Usage: $0 <PDF-even-pages-file> <PDF-odd-pages-file>"
exit 1
}
# Add leading zeros to pad numbers in filenames matching the pattern
# $prefix$number.pdf. This allows filenames to be easily sorted using
# sort.
# $1 : The prefix of the filenames to consider
function add_leading_zero {
prefix=$1
baseprefix=$(basename $prefix | sed -e 's/[]\/()$*.^|[]/\\&/g')
dirprefix=$(dirname $prefix)
for filename in "$prefix"*".pdf"
do
base=$(basename "$filename")
index=$(echo "$base" | sed -rn "s/$baseprefix([0-9]+).pdf$/\1/p")
newbase=$(printf "$baseprefix%04d.pdf" $index)
mv $filename "$dirprefix/$newbase"
done
}
# Interleave pages from two distinct PDF files and produce an output PDF file.
# Note that the pages from the even pages file (second file) will be used in
# the reverse order (last page first).
# $1 : Odd pages filename
# $2 : Odd pages filename with extension removed
# $3 : Even pages filename
# $4 : Even pages filename with extension removed
# $5 : Unique key used for temporary files
# $6 : Output file
function pdfinterleave {
oddfile=$1
oddbase=$2
evenfile=$3
evenbase=$4
key=$5
outfile=$6
# Odd pages
pdfseparate $oddfile "$oddbase-$key-%d.pdf"
add_leading_zero "$oddbase-$key-"
oddpages=($(ls "$oddbase-$key-"* | sort))
# Even pages
pdfseparate $evenfile "$evenbase-$key-%d.pdf"
add_leading_zero "$evenbase-$key-"
evenpages=($(ls "$evenbase-$key-"* | sort -r))
# Interleave pages
pages=()
for((i=0;i<${#oddpages[@]};i++))
do
pages+=(${oddpages[i]})
pages+=(${evenpages[i]})
done
pdfunite ${pages[@]} "$outfile"
rm ${oddpages[@]}
rm ${evenpages[@]}
}
if [ $# -lt 2 ]
then
usage
fi
if [ $1 == $2 ]
then
echo "Odd pages file and even pages file must be different." >&2
exit 1
fi
if ! hash pdfunite 2>/dev/null || ! hash pdfseparate 2>/dev/null
then
echo "This script requires pdfunite and pdfseparate from poppler utils" \
"to be in the PATH. On Debian based systems, they are found in the" \
"poppler-utils package"
exit 1
fi
oddbase=${1%.*}
evenbase=${2%.*}
odddir=$(dirname $oddbase)
oddfile=$(basename $oddbase)
evenfile=$(basename $evenbase)
outfile="$odddir/$oddfile-$evenfile-interleaved.pdf"
key=$(tr -dc "[:alpha:]" < /dev/urandom | head -c 8)
if [ -e $outfile ]
then
echo "Output file $outfile already exists" >&2
exit 1
fi
pdfinterleave $1 $oddbase $2 $evenbase $key $outfile
# SO - Bash command that prints a message on stderr
# http://stackoverflow.com/questions/2643165/bash-command-that-prints-a-message-on-stderr
# SO - Check if a program exists from a bash script
# http://stackoverflow.com/questions/592620/check-if-a-program-exists-from-a-bash-script
# SO - How to debug a bash script?
# http://stackoverflow.com/questions/951336/how-to-debug-a-bash-script
# SO - Escape a string for sed search pattern
# http://stackoverflow.com/questions/407523/escape-a-string-for-sed-search-pattern
You can use the Mix module in PDFsam Basic (free and open source) or do it online using the Alternate & Mix feature in Sejda
I was looking to do basically the same thing, and Stéphane Chazelas's answer was very helpful. I do this often enough that I wrote a simple Python script to automate things, using the commands he suggested. By default, it reverses the order of the even pages, but this can be suppressed with a command line flag.
The question is kind of old, so I expect the needs of the original asker have already been met. However, it is possible that the script will be useful to people who arrive here in the future, so I have placed it below.
#!/usr/bin/python
"""A simple script to merge two PDFs."""
import argparse
from os import listdir
from os.path import join as opjoin
import shutil
from subprocess import check_call, CalledProcessError
import tempfile
SEPARATE = 'pdfseparate %s %s'
MERGE = 'pdfunite %s %s'
def my_exec(command):
"""Execute a command from a shell, ignoring errors."""
try:
check_call(command, shell=True)
except CalledProcessError:
pass
def run(odd, even, out, reverse_odd=False, reverse_even=True):
"""Interleave odd and even pages from two PDF files."""
folder = tempfile.mkdtemp()
my_exec(SEPARATE % (odd, opjoin(folder, 'odd%d.pdf')))
my_exec(SEPARATE % (even, opjoin(folder, 'even%d.pdf')))
odd_files = []
even_files = []
for curr_file in listdir(folder):
filepath = opjoin(folder, curr_file)
if curr_file.startswith('odd'):
odd_files.append((filepath, int(curr_file[3:-4])))
elif curr_file.startswith('even'):
even_files.append((filepath, int(curr_file[4:-4])))
func = lambda x: x[1]
odd_files.sort(key=func, reverse=reverse_odd)
even_files.sort(key=func, reverse=reverse_even)
parts = []
for line in zip(odd_files, even_files):
parts.append(line[0][0])
parts.append(line[1][0])
my_exec(MERGE % (' '.join(parts), out))
shutil.rmtree(folder)
if __name__ == '__main__':
parser = argparse.ArgumentParser(description='Merge two PDF files.')
parser.add_argument('odd_pages', help='PDF containing the odd pages.')
parser.add_argument('even_pages', help='PDF containing the even pages.')
parser.add_argument('output_file', help='The target output file.')
parser.add_argument('--reverse-odd', action='store_true',
help='Insert the odd pages in reverse order.')
parser.add_argument('--no-reverse-even', action='store_true',
help='Suppress reversal of the even pages.')
args = parser.parse_args()
run(args.odd_pages, args.even_pages, args.output_file,
args.reverse_odd, not args.no_reverse_even)
