InDesign Displaying images blurry when exporting at High Quality PDF

[allisonh37240426]

Hi, I'm putting together a small print ad (3.5 x 2.25), but my InDesign images export grainy in my High-Quality Print PDF (default from InDesign). This was a struggle from last week that I'm still curious about. I asked Adobe Chat, and they said to update my OS and InDesign, which I did. But I'm still getting the same results. I place the bottle in my InDesign file, and it looks good. Displays high quality. Not missing an image, large enough, 300 res, CMYK, all that. But when I export as a HQ Print PDF, it looks grainy.

I've just never had the issue before with any size doc and images. I ended up having to recreate in Illustrator to get the images to display properly on my PDF. I'm attaching an image to show what an example looks like. Thank you for any help or suggestions!

[HARSHIKA_VERMA]

Hi @allisonh37240426,

Thank you for reaching out, and sorry for the trouble. Would you mind telling us if this is happening with a specific file or all files? Please share the version of InDesign and the details of your operating system. 

Is it possible for you to share the file with me via private message so that we can investigate on our end?

We will try our best to help.

Thanks,

Harshika

[allisonh37240426]

Hi, yes - so the version of InDesign I'm using is 19.3. OS Sonoma 14.4.

I can send you the files if you want to take a look. I'm not sure if it's because the image I'm scaling down to be so small or what. I've never noticed this happening before. How would I go about sending the packaged files to you?

[James Gifford—NitroPress]

What is the actual pixel size of the image file? (1000x2000 pixels, etc.)

When selected in ID, what does Info say the effective PPI is?

And have you tried resetting the PDF export profile to base/default, not changing a thing, and exporting? How about Press Quality?

[allisonh37240426]

I've tried two versions to test PPI -
First attempt was an effective PPI of 1541, second was 509. They both came out looking the same at export. I also tried Press Quality PDF setting, and it also looked the same. 

[James Gifford—NitroPress]

Okay, that's puzzling. The first cause of problems like this is usually a source image that is way below resolution needs, and the fault is being overlooked for some reason.

If you are using the default/unmodified PDF export settings, I can't think of a further reason you'd be getting such a substandard result. But there are more knowledgeable PDF minds here....

[rob day]

Hi @allisonh37240426 , I think Brad @ Roaring Mouse and @Scott Falkner  are right, if the placed file’s Effective Resolution is significantly higher than the Compression>for Images above setting (450ppi), the downsample would lower the export resolution. Here the Actual PPI is 300 and the Effective PPI is at your reported 1541:

The exported PDF at the same zoom magnification:

The same export, but with the Export>Compression>Do Not Downsample:

[leo.r]

Where are the linked images located - on your local drive or a server? If it's the server, will it make a difference if you copy the images to your local drive and relink to them?

[Scott Falkner]

Would you be willing to share the PDF?

I have a guess as to what the problem is. Nothing. Because your document size is so small the image is downsampled to 300 ppi which, when opened full screen on a large monitor, looks pixelated. What is the effective PPI of the image when using Acrobat's preflight tools? Or, open the PDF in Photoshop and select images. There you can open any image embedded in the PDF and examine the size and resolution.

[James Gifford—NitroPress]

That's an excellent point (often overlooked in 'problems' with banner ads) but I'd think a 3-inch ad could maintain better resolution  — better 'visual' resolution, if nothing else — than the OP's example shows. Unless the ad is being blown up well past actual print size for comparison, in which case, yes, you'd get some lovely blurring and low res — it does seem there's an actual problem here.

[Eugene Tyson]

Can you place the images into a separate new document and export?
Do they export ok from a new document?

If so - then there's underlying issues with your current file.

Try 
File>Export 

Choose IDML

Open the IDML in InDesign
Save the file as a new InDesign file with a new name
See if the issue persists.

[Brad @ Roaring Mouse · Accepted solution]

Since the effective resolution of your graphic was above 450, it is being downsampled to 300 according to your PDF Export Compressions settings. The result will still be good enough for print, but yes, will suffer on display if you zoom in.

If you want to avoid the issue, turn OFF downsampling or increase the threshold to, say, 600.

 

 

 

[James Gifford—NitroPress]

I still dunno. At 300ppi, that spray can would still be 900-ish pixels high, enough for better resolution than we're seeing, even if the capture is blown up too much. It looks like ~100ppi at best to me.

Have to see actual file samples to get any further, though.

[Eugene Tyson]

Could be flattening phenomenon I've seen 72 PPI images upped to 300 and vice versa. It's incredibly difficult to know

[allisonh37240426]

Thank you! I tried this out, and this was the issue. I appreciate everyone's feedback here and in determining what was going on. I figured it had to be something I was missing, but didn't think about my image being too large and sampling down!