Merge two PDF files containing even and odd pages of a book
Solution 1:
A simple solution would be to use only pdftk in the following way:
pdftk A=odd.pdf B=even.pdf shuffle A Bend-1 output merged.pdf
This also works if odd pages are scanned first and then even:
pdftk A=file.pdf shuffle A1-X Bend-Y output new-file.pdf
where X is the last odd page and Y is X+1.
Solution 2:
From the PDFtk homepage:
PDFtk has a special feature that we added specifically to solve this problem of arranging scanned pages: shuffle. Say you have two PDFs: even.pdf and odd.pdf. Then you can collate them into a single document like this:
pdftk A=odd.pdf B=even.pdf shuffle A B output collated_pages.pdf
If your even pages are in reverse order, you can reverse its page range:
pdftk A=odd.pdf B=even.pdf shuffle A Bend-1 output collated_pages.pdf
The shuffle feature works by taking one page at a time from each of the input page ranges and assembling them into a new PDF. You specify these ranges after the shuffle keyword, and you can have more than two ranges.
An example of the use of more ranges is:
pdftk A=odd.pdf B=even.pdf shuffle A1 B1 A5-6 B2-3 output out.pdf
in which case the output contains the first page of A (A1), the first page of B (B1), then the fifth page of A, the second of B, the sixth page of A and finally the third page of B.