pdf resolution

[mallokw]

Hello,

I am working in an indesign document that will be printed. In that document I have a pdf file image (that contains only this image). From what I know, there is no resolution in a pdf (or there can be as many as the number of files contained in the pdf).

- But How do I check if my pdf image has a sufficient ppi for my printed document ? 

- Is it ok to convert the pdf file into a psd file with the right ppi ?

Thanks for your help

MK

[BobLevine]

Open the PDF in Acrobat and do a flightcheck there.

[rob day · Accepted solution]

Also, InDesign’s Preflight will check images inside of placed PDFs:

[mallokw]

Dear Bob,

Thanks for your answers.

According to what you say, it means that we cannot check the image resolution in Indesign unless it is under the ppi minimum requirement ?

Thanks.

MK

[rob day]

Right, but you can set any minimum.

If you want to see the actual resolution(s) inside of the placed PDF you would have to inspect it in AcrobatPro, or preflight the final PDF in Acrobat, which would list all of the image resolutions.

[Bevi Chagnon - PubCom.com · Accepted solution]

Yes, check the InDesign document before making the PDF.

Adobe's online help manual for InDesign is at https://helpx.adobe.com/indesign/user-guide.html   See these sections:

• https://helpx.adobe.com/indesign/user-guide.html/indesign/using/graphics-links.ug.html
• https://helpx.adobe.com/indesign/user-guide.html/indesign/using/preflighting-files-handoff.ug.html#d...

There are 2 ways to check the resolution of graphics in InDesign: 1) Individually, graphic by graphic, or 2) globally through Preflight.

Method #1: Individual graphics.

• Select the graphic and locate it in the Links Panel.
• In the lower portion of the panel, you'll see the information about the graphic.
• Effective Resolution is what matters; it's the resolution that it will be printed at.
• Usually for press/print, you'll want at least 300 ppi: 400 ppi is preferred for modern printers and quality jobs.
• Note: This method does not check images inside placed PDFs.

Checking a graphic's Effective Resolution.

Method #2: Globally.

• Select a Preflight Profile and either check its options re: resolution, or create a new profile.
• Under the IMAGES and OBJECTS section of the profile, select the option Image Resolution, and set the minimum resolution to 300 ppi for color and grayscale images.
• See Rob Day's screen capture, above.
• Preflight does check the graphics inside placed PDFs.

[mallokw]

Bevi,

Thanks for this detailled solution ! It's so clear now on pdf resolution checking methods.

All the best.

MK

[Bevi Chagnon - PubCom.com]

You're welcome!

One more idea: since InDesign treates PDFs as graphics, then check the PDF's resolution before placing it in InDesign. See @BobLevine's comment above.

Use Acrobat's Preflight Tool to check each graphic's resolution, one-by-one. Click each raster/bitmap graphic and check the resolution in the dialogue box.

How to check resolution of a graphic in Acrobat Pro.

See this thread for more background details: https://community.adobe.com/t5/acrobat/how-to-verify-the-resolution-of-a-pdf/td-p/9226360?page=1

[mallokw]

Yes it's a good method to check pdf resolution in Acrobat before importing in Indesign but it does not solve the fact that you have no clue to verify the % size in Indesign unless it is under the minimum resolution defined requirement in preflight that gives you the notification.

Wouldn't it be convenient to convert the pdf image into a PSD file ?

Have a nice day.

MK

[BobLevine]

No! You would wind up rasterizing everything.

[mallokw]

Ok but if the image inside the pdf is just pixels (photography or drawing without text nor vector file) ?

[BobLevine]

Then extract the image and use that.

[mallokw]

Ok well, I didn't know it was possible : Export pdf as tiff ?

Thanks.

MK

[rob day]

If you find a PDF with an image under the resolution rule, how would you fix the problem—up sample in Photoshop? That solves the resolution rule problem, but doesn’t change the quality problem.

[rob day]

Why does setting a minimum resolution in the ID preflight not work? If you set it to something like 300 and don’t get an error there isn’t a resolution output problem, if it catches an error in a PDF you’ll know to open the PDF and run a preflight to find the problem image[s]. 

[Bevi Chagnon - PubCom.com]

Which leads us to conclude: There isn't a one-size-fits-all solution to this because PDFs can contain any combination of raster graphics, vector graphics, live text, and rasterized text.

My best recommendation is to convert the PDF into a live InDesign file, which then lets me control all the different pieces, view their resolution, and correct things accordingly.

[Jens Trost]

Hi there,
just wanted to add for feature reference:
In addition to the great explanations already given, you can set additional columns, including effective ppi, in the links panel. This gives you the possibilty to sort after resolution and then get a quick overview over the resolutions in your indd document.

Click on the flyout menu of the links panel, at the botton "Panel options" and then select to your liking:

[Laubender · Accepted solution]

MK said:

"Ok but if the image inside the pdf is just pixels (photography or drawing without text nor vector file) ?"

Hi MK,

then you also could open the PDF in Acrobat Pro DC, select the image and open it with PhotoShop.

From there you could save it to a new file and place that file in your layout in InDesign.

Workspace in Acrobat Pro DC: Edit PDF

Image is selected.

The context menu is showing option:

Edit Using > PhotoShop

Regards,
Uwe Laubender

( ACP )

[mallokw]

Hello Uwe,

Thanks a lot for this explaination. This is exactly what I what looking for... I think this is more convenient to isolate the file and then to be able to check the size directly in Info Panel or % size in Indesign.

Thanks again.

Regards,

MK