Possible Duplicate:
How can I split a PDF's pages down the middle?
I have a pdf file that was made into a booklet format. It is meant to print on A4 paper in landscape orientation; here are two pages in the pdf, which should correspond to four pages in the actual book.
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| (1) | (3) |
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| (4) | (2) |
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The bracketed numbers correspond to the order of the individual pages.
I know that there are all sorts of commands (pdfbook, pdfnup, etc.) on linux (which was probably used to make this booklet in the first place). How do I 'unbook' it---that is, I'd like to make a pdf document from this where each individual page of the final product is an individual page of the pdf, ordered in the usual way.