How to see an embedded image's dpi (ppi) in a pdf in Acrobat Pro?

Question

The following situation baffled me slightly: after preparing a pdf in a different program I wanted to make sure that an embeded image in the pdf file had the right dpi, yet I found no way in adobe acrobat pro to inspect the file/image dpi.

Can that be, or am I missing where this feature is hidden?

Answer 1

You can use the build in Preflight function. [I don't know when it has been introduced but its there in Acroboat 9 Pro and above]

Advanced > Preflight [Keyboard Shortcut Shift + Ctrl + X ]

Have a look at this video to see what I mean:

http://www.mattbeals.com/videos/Adobe/ShowImageRes/ShowImageRes.html

There are also other plugins and stuff, but as there is this built in option I don't think you'll need it.

For more stuff on the topic just google for " image dpi in pdf " and you'll find lots on the topic.

Good Luck!

Answer 2

Here's a full step-by-step (based on Adobe Acrobat Pro X):

To quickly do it now

1. Edit > Preflight (or shift & cmd/ctrl & x)
2. Under 'PDF Analysis', select List page objects, grouped by type of object, then hit Analyze

3. The results break your images out into handy ranges:

4. Open these out, and you get a list of images. Clicking any takes you straight to that image, with a dotted line around it.

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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.

Answer 3

Using Acrobat Pro's Output Preview dialog:

First, make sure the measurement units in your Preferences are set to inches. This dialog will show the resolution in "pixels per unit", and traditionally image resolution is measured in pixels/inch. (Adobe may not realise that.)

1. Call up the Output Preview dialog. Its location in the drop down menus is different from one Acrobat version to another, so I added it to my standard toolbar:
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2. The default option is to show "Separations"; the third choice in the 'Preview' list is "Object Inspector". Select this option.
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3. Now details will be shown for every object you click on. For bitmap images, this includes both horizontal and vertical resolution in the section "Image Attributes".
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