Automator workflow for interleaving odd and even pages of PDF scans

I have made an Automator workflow that combines two PDFs, by shuffling (interleaving them), but after reversing the second one (second in terms of creation time). This means that you can scan a whole lot of pages (odd sides), turn them over and scan the other sides (even sides), then right click, choose an Automator workflow to combine them. They become Combined.pdf in the same folder - the originals are moved to the Trash.

Uses the python script automator action

http://www.apple.com/downloads/macosx/automator/runpythonscript.html

This was something also wanted here.

The automator action starts with a Get Selected Finder Items action, then has a Run Python Script action with the following code.

import os

from CoreGraphics import *

def createPDFDocumentWithPath(path):

print path

return CGPDFDocumentCreateWithProvider(CGDataProviderCreateWithFilename(path))

def duplexPages(writeContext, oddfile, evenfile):

# open PDFDocuments for each of the files.

odd = createPDFDocumentWithPath( oddfile )

even = createPDFDocumentWithPath( evenfile )

# confirm that the number of pages is the same

maxPages = odd.getNumberOfPages()

if ( maxPages <> even.getNumberOfPages() ):

print "Documents do not have the same number of pages"

else:

# Shuffle the pages

for pageNum in xrange(1, maxPages + 1):

# start at first odd page

page = odd.getPage(pageNum)

print 'Page', pageNum, 'from', oddfile

if page != None:

mediaBox = odd.getMediaBox(pageNum)

writeContext.beginPage(mediaBox)

writeContext.drawPDFDocument(mediaBox, odd, pageNum)

writeContext.endPage()

# start at last even page

page = even.getPage(maxPages + 1 - pageNum)

print 'Page', maxPages + 1 - pageNum, 'from', evenfile

if page != None:

mediaBox = even.getMediaBox(maxPages + 1 - pageNum)

writeContext.beginPage(mediaBox)

writeContext.drawPDFDocument(mediaBox, even, maxPages + 1 - pageNum)

writeContext.endPage()

def realFilesOnly( item ):

return item.find(".") <> 0

# from http://stackoverflow.com/questions/249785/os-x-determine-trash-location-for-a-given-path

def get_trash_path(input_file):

    path, file = os.path.split(input_file)

    if path.startswith("/Volumes/"):

        # /Volumes/driveName/.Trashes/

        s = path.split(os.path.sep)

        # s[2] is drive name ([0] is empty, [1] is Volumes)

        trash_path = os.path.join("/Volumes", s[2], ".Trashes", str(os.getuid()))

        if not os.path.isdir(trash_path):

            raise IOError("Volume appears to be a network drive (%s could not be found)" % (trash_path))

    else:

        trash_path = os.path.join(os.getenv("HOME"), ".Trash")

    return trash_path

def main(input, *args, **kwargs):

dirname = os.path.dirname(input[0])    # extract folder to work in

# print dirname

files = input

# print files

# files = os.listdir( dirname )

# files = filter(realFilesOnly, files) # filter out special files

# print files # enable to see which files are selected

if ( len(files) == 2 ):

# files[0] = os.path.join(dirname,files[0]) # add path to files 

# files[1] = os.path.join(dirname,files[1])

# odd file is assumed to be the earlier one

if ( os.path.getctime(files[1]) > os.path.getctime(files[0]) ):

odd = files[0]

even = files[1]

else:

odd = files[1]

even = files[0]

print "Identified Odd: ", odd

print "Identified Even: ", even

outputFilename = os.path.join(dirname, "Combined.pdf")

print "Output to: ", outputFilename

pageRect = CGRectMake (0, 0, 612, 792)

writeContext = CGPDFContextCreateWithFilename(outputFilename, pageRect)

duplexPages(writeContext, odd, even)

# delete the original files

trashPath = get_trash_path( odd ) # find location of trash

os.rename( odd, os.path.join(trashPath,os.path.split(odd)[1]) )

os.rename( even, os.path.join(trashPath,os.path.split(even)[1]) )

else:

print "Incorrect number of files"

return files

It can be saved as a Finder Plugin to appear on the context menu for Finder items.