I have multiple 300+ page PDFs that are published every 2 months. About 80% of the pages do not change between publication cycles. The 20% of the pages that do change need to be extracted, cropped and output to individual .png files. Every page includes the month and year that the page was last revised in the lower left corner of the page, so it is easy to identify the changed pages by searching for pages that have the latest month/year on the page (ie., a single search for August 2013 would bring up all the changed pages for the August print cycle). In terms of cropping, all pages would be cropped identically.
I am looking for a way to automate this process in either Acrobat Pro or Enfocus Pitstop: searching for changed pages using search term "month year", crop, extract pages into individual pdf files, export as .png. Would this be possible?