Here's a full step-by-step (based on Adobe Acrobat Pro X):
To quickly do it now
- Edit > Preflight (or
- Under 'PDF Analysis', select
List page objects, grouped by type of object, then hit
- The results break your images out into handy ranges:
- Open these out, and you get a list of images. Clicking any takes you straight to that image, with a dotted line around it.
To create a check for a specific PPI
If you do this a lot and have a specific standard you want to always hit (e.g. if you routinely need to check all images exceed 300 PPI), you can create a preflight profile to make it a simpler process:
Then in the "Images" tab you can set it to give you an error message or a warning when you run this preflight check if any image is below (or above) a set PPI:
The handy thing about preflight profiles is, you can include any checks you want at once. So you can also include other common checks, like warning you if anything is in RGB, listing fonts, warning you if any fonts are not embedded, mentioning if there's an odd number of pages or if any pages are blank, etc etc, all in one handy one-button check.