I don't know what would be your preferable way of telling the system what pages should be color or grayscale, but here is an idea.
Assume you have a manifest like this:
file;colorpages
C:/files/doc1.pdf;[0,2,4]
C:/files/doc2.pdf;[1,4,5,7]
where the first column is the pdf to use and the second one what pages should be color.
When you map this on the hot folder for a workflow, in the MAX Setup use the pdf as column A and map column B as a custom field. Here I called it pagerange. This will give you the variable $FFpagerange$ that will be used later.
A workflow like this:
First Save component saves the job to C:\Out\ with the job name.
Then a Manage Color component that converts to grayscale. Could be done with a Preflight also.
Then a second Save component to C:\Out\ with the job name but with the addition _gray.
Now you have both the original pdf and the grayscale version of it in C:\Out\. Now a new pdf will be created that uses both those files and the variable $FFpagerange$ to determine if a color page or a grayscale page should be added to the new pdf. This will be taken care of by the last component which is an External Process that uses a batch file with the parameters:
"$FFin$" "$FFout$" "$FFwfJob.jobName$" "$FFpagerange$"
The batch file looks like this:
"C:\Program Files\Python38\python.exe" "C:\Xerox\FreeFlow\Core\00000000-0000-0000-0000-000000000000\Data\Scripts\mergecolorandgray.py" %1 %2 %3 %4
The batch file calls a Python script that looks like this:
import sys
import os
import ast
from PyPDF2 import PdfFileWriter, PdfFileReader
colorpages = ast.literal_eval(sys.argv[4])
infile_color = PdfFileReader('C:/Out/' + sys.argv[3] + '.pdf', 'rb')
infile_gray = PdfFileReader('C:/Out/' + sys.argv[3] + '_gray.pdf', 'rb')
output = PdfFileWriter()
for i in range(infile_color.getNumPages()):
if i in colorpages:
p = infile_color.getPage(i)
output.addPage(p)
else:
p = infile_gray.getPage(i)
output.addPage(p)
with open(sys.argv[2] + '\\' + os.path.basename(sys.argv[1]), 'wb') as f:
output.write(f)
os.remove('C:/Out/' + sys.argv[3] + '.pdf')
os.remove('C:/Out/' + sys.argv[3] + '_gray.pdf')
What happens is that the Python script reads both saved pdf files. It then checks if the page is in $FFpagerange$. If it is, then a page from the original pdf is added and if not then a grayscale page is added. (Page counting starts with 0. If you would like to input page numbers that you are used to then the script has to modified.)
Both scripts have to be placed in the FreeFlow Core scripts folder. I have my scripts folder on C:\. If you have your scripts folder somewhere else then you need to change the drive letter/path in the batch file.
Also, this requires Python https://www.python.org/downloads/ to be installed on your FreeFlow Core server. After Python is installed you need to install PyPDF2. From command line as admin run:
pip install PyPDF2
Depending on where Python is installed you might need to change the path to python.exe in the batch file.
All done.
I have also attached both scripts.
If you dont' want to use a manifest for this, then you could for instance use a pdf keyword (or some other variable that could be included in the pdf itself) with the information of what pages should be in color.
You then need to replace "$FFpagerange$" with the variable "$FFwfdoc.Keywords$" in the External Process component.
/Stefan