A PDF files does not actually have a resolution since it contains many different objects (maybe text, line art, images, stamps, watermarks, movies etc.) and each of those objects might or might not have a resolution. If you wish to check the resolution of any images from within a PDF then use the preflight tool within Acrobat 8 Professional. There are profiles which come as default such as ‘List All Images’ and List Images Below xxx ppi’. This will enable you to now accurately check image content against your resolution threshold. Finally to save time, you can include a resolution check as part of your preflight procedure, therefore checking for lots of other potential problems at the same time.
This FAQ was written by [url=http://www.acrobatusers.com/community/profile/jon.bessant]AUC Expert Jon Bessant[/url].