[dedachan]

FOR MAC USERS:

So far, the best I've come up with is to highlight the thumbnais that appear in the Preview application and then combine the even and left sides with the Alternate Mix function on pdfsam. This way, I don't have to crop the pages individually.

Here's how I did it (it's much simpler than it looks once you try it):

For clarity, pages refers to the pages of the PDF file, and sides to the ones of the original scanned text.

1. Create two copies of the pdf file and add EVEN and ODD to their names.

2. Open the EVEN file with the Preview applicaton. On the right, there should be a row of thumbnails for all the pages. Click and drag until you have highlighted all of them. If you don't see the thumbnails, press SHIFT+Command+D. This will make the side bar appear.

If the pages are flipped the wrong way, you can press command+L or command+R to turn them either left or right. If all thumbnails are selected, this will work for all pages simultaneously. If not, it will work on individual pages.

3. With the thumbnails still highlighted, use command+3 and select the even side of your first page. Even though you are only doing this to the first page, it will actually work for all even sides on all the pages of your file. The part you want to preserve should be INSIDE the selected area.

4. Press command+K to crop the page. You should now have a document wich contains all of the even pages.

5. Save (or Save As, if you skipped the 1st step... and change the name! You don't want to accidentally overwrite your original file).

6. Repeat process with your ODD file, only select the odd sides this time.

7. Open pdfsam (it's free to download), go to Alternate Mix, and drag the ODD and EVEN files below where it says File Name. Make sure the file that has the FIRST page is listed before the other one (there are move up/move down buttons on the right corner).

8. In the Mix Options, make sure Reverse first document and Reverse second document are both unchecked. Where it says "Number of pages to switch... ", there should be the number 1 (for both).

9. Chose your destination folder and name your file (again, make sure not to overwrite your original pdf), then press the run button to generate the new PDF.

Hope this was helpful.