How do I know the resolution (DPI?) of a PDF file?

[dublove]

How do I know the resolution (DPI?) of a PDF file?

Can you see it in Acrobat?

[Thom Parker]

Raster images have a dpi, but the page content of a PDF is a vector graphic, which does not have dpi.  Vector graphics can scale to any size without lose of quality, essentially an infinate dpi. 

That said, PDF page content can include raster images.  In that case, the part that is a raster image has a dpi rating, and it can be seen in Acrobat. 

[JR Boulay · Accepted solution]

To know the resolution of an image open the Print Production tools: Output Preview, Select the Object Inpector an clic on any image.

[dublove]

Thank you very much. It's a good idea.

[DEMACO]

This is very helpful, thanks!

[DEMACO]

As the author mentions, you must left click on the image with your mouse pointer to get the attributes.

[Denise37672996uidr]

I print lots of labels for my small business. Up until recently, when I got my file ready to print, I was able to select "print on both sides" and select ADVANCED settings to change the dpi from 600 to 1200.

Tonight, I was NOT able to see the "print on both sides" NOR see any advanced settings that include the dpi changes.

I have a Canon MF753CDW printer and have had no issues til now. Not sure what could be causing the issue.

I've removed and re-installed the printer. I've cleaned the printheads according to manufacturer recommendations. I have been printing labels since September in the EXACT Same manner with no issues til now.

Not sure if it's an update in Windows, Adobe, or Canon.

Any thoughts?

[Ken the Book Printer]

You can use the preflight tool to check the DPI (dots per inch) and scan all the images. However, you’ll need to set up a custom profile. Go to the preflight tool, create a new profile, set it to check images below a certain DPI, and then run the analysis.

https://kenthebookprinter.com/resource/how-to-arrange-pages-for-booklet-printing

[danb37112406]

Why wouldnt Adobe have an EASY TO FIND option to view a file's color profile and resolution? Its not as though these are esoteric questions people have when they are working with a PDF. Ridiculous. Acrobat has been "improved" over the years to be more and more frustrating. I really hate the app at this point and would use other options if it wasnt still industry standard.

[Dave Creamer of IDEAS]

A PDF can be a mixture of resolutions or none at all (if all vector), and a mixture of color profiles depending on how the PDF was generated. So, there would be no clear answer.

A majority of the users are business users with no need to have that info handy. If one is in the prepress industry, one _probably_ knows how to find out or asks someone who does know.

[danb37112406]

Ridiculous. There IS a resolution for a PDF when generated . Of course various elements within the PDF may be placed with different resolutions – but the general PDF is created at a specified resolution(as seen in the PDF spec window when one creates a PDF). Having been in the graphics world for 25+ years, I know this is a common question not only of designers, but when someone at a print shop receives such a file. After working with Adobe customer service for 30mins, there IS a place where this data is available – unfortuantely it is burried and unclearly labeled with Acrobat tools. Seems document resolution, document size and color profile are VERY basic points for any PDF print file. The question is: why not have a SIMPLE and clear option for this data? Its silly.

For anyone else who has torn their hair out trying to obtain the info, it can be found: Tools: Use Print Production: Output Preview – go to the "Preview" dropdown and select: Object Inspector: then (without direction on what to do next) note that your cursor has changed to a crosshairs – select the section you want to get the resolution for and (if its a photo) it will give it.

[Dave Creamer of IDEAS]

I think we are talking about two different resolutions--referring to Distiller, the resolution under General is aimed at the output device. I was referring to (what I think most users would ask about) the settings under Image. 

Some additional info: https://community.adobe.com/t5/acrobat-discussions/how-to-verify-the-resolution-of-a-pdf/td-p/922636...

Now need to throw around your inexperience of only 25 years. Some of us have been doing it almost twice as long.  🤣🤣

[danb37112406]

Youre still only talking of the resolution. There is the issue of the color profile in which the document was created as well as the final print size. Both very basic fundamentals for printing – both bits of data are attainable, but again burried in way overly technical and esoteric locations. All of these points used to be more or less at ones finger tips in earlier versions of Acrobat (before it was made awful). 

Re how long Ive been using it –more like 30yrs (back in the early 90s). I'm pretty sure thats when it was released, so Im going to call BS on your "2x as long" line, my friend.

[Thom Parker]

And I completely agree with you about the terrible changes in Acrobat that make finding info much more difficult. 

[Dave Creamer of IDEAS]

That's twice you have been rude. That's unnecessary. 

You mentioned having "been in the graphic's world for 25+ years". That would put you at around 1998-2000 depending on how you define "+". I started in the graphics world in 1980. That's 45 years, or as I said _almost_ twice as long. Now, with computers (Mac 512 and PageMaker), I started in 1985 and continued from there.

[Thom Parker]

Just to add to the discussion, and I think this is mentioned in previous comments, but the PDF itself does not have a resolution.  The page content of a PDF is vector graphics. The vector graphics can include raster images that are placed on the page.  Now of course, a page that was created from a scan will be one big raster image. So in this case you could say the page has a resolution, but really its just the resolution of an image on the page, which happens to take up all the space. 

So that is the PDF itself, but of course the PDF is rendered onto a screen or print device that does have a resolution. This is a completely different thing that is outside the PDF. 

[JR Boulay]

"Object Inspector: then (without direction on what to do next) note that your cursor has changed to a crosshairs – select the section you want to get the resolution for and (if its a photo) it will give it."

By using this tool, you should be able to see for yourself that each image has its own resolution, and that vector objects (text, artwork) do not have a resolution.