on 05/01/2018, Bill Wright supposed :
Firstly use the gamma ('lighting') tool to get a good white and decent black.
Save.

Either use the rectangular selection tool to select one page then edit copy,
new file, (or 'new file from clipboard'), edit paste, save as 'page 01'.
Repeat for all pages.

Or
Use the crop tool to crop to just one page. Save AS 'page 01'. Re-open the
original file and repeat for all pages. Remember to use Save AS, not save.

Thanks all, and thanks Bill - that worked perfectly..