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I place a 300 DPI Bitmap (B&W, 1-bit) image into an InDesign document, export it to PDF, and in Acrobat Print Preview it shows as 21600 DPI. Is anyone else seeing something similar, or able/unable to recreate the issue? Thanks in advance. (Note, the final PDF looks and prints properly, it's just that on inspection the DPI is wrong, and I fear that the recipient might take issue with the PDF files).
1. I Create a 300x300 pixel image, at 300 DPI, as a bitmap B/W image, and save as TIF
2. I create a new InDesign document, and place the Black and White image into the document.
3. I export the InDesign document as PDF/X-1a
4. I open the PDF with Acrobat DC, Print Production, Output Preview, Object Inspector.
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Did you scale the image?
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Check in InDesign whether the image is in at 100%. In order to get a resolution close to what you got in the pdf the image would be in the InDesign file at approximately 1%.
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I've noticed that AcrobatPro's Output Preview's Object inspector does that with all 1-bit images. i don't think there's anything you can do about it.
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https://forums.adobe.com/people/rob+day wrote
I've noticed that AcrobatPro's Output Preview's Object inspector does that with all 1-bit images. i don't think there's anything you can do about it.
Right. Can't matter much. Obviously the mis-report doesn't change content materially.
mariog69599891 wrote
...I fear that the recipient might take issue with the PDF files
Direct them to this thread.
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It's not Acrobat. It's that ID has always written the information wrong. This has gone on since at least as far back as CS5 if I recall properly. The bit info is wrong, too.
Here's an example from ID:
Same image out of QXP:
And if you look at the ID example, they are identified as 4 bits per px. PS doesn't think so...
Mike
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Thanks for the additional information Mike. It's what I suspected, but still a bit troubling to learn it's been a long-standing issue.
I guess that since the images visually appear normal (and aren't .25" x .25" as indicated) that it's just the information that's wrong, and not the actual image itself. Hopefully this would be acceptable to the people who are requesting the files.
Can anyone recommend a tool that will show the information for the actual images in the PDF?
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Ask in the Acrobat prepress forum
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Enfocus PitStop Pro (plug-in for Acrobat Pro) correctly reports the resolution.
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Try this image and export PDF/X1-a.
If I export your tiff to PDF/X-1a directly from Photoshop, I get the correct res. If I place the original tiff and the saved Photoshop PDF in ID, the tiff has the wrong res, but the Photoshop PDF is correct:
The placed 1-bit PDF
The placed tiff
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Yeppers. Thanks, Rob.
I get the correct readout from everything except ID. Interesting that the PS PDF ends up correct in the resulting PDF. Hadn't tried that.
I am interested if Pitstop reads it correctly. What I don't know about Acrobat and its Object Inspector is whether it is reading the metadata of the object in a PDF or whether it is reading the actual image itself. If Pitstop reads it correct, I would reckon it is the latter.
Also, I would be remiss if I didn't explicitly point out what should be obvious. That is, there are no issues with such a file in a PDF from ID as regards it imaging properly. Else the forum would have been continuously flooded for a bit and the ID team would have rectified the issue.
I cannot remember now how I found out about this. I thought it was here on the forum many moons ago. But searching (such as it is) didn't turn up anything relevant. But may be that I learned about it jawing with the people down at my main service bureau.
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I can reproduce here.
1" x 1" image @300ppi, bitmap mode
Placed in InDesign, unaltered; Link Info values identical to OP's screenshot (size in bytes slightly different).
Export using PDF/X-1a:2001 preset
Acrobat DC Pro Object Inspector report identical to OP's screenshot
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The output dimensions always get listed as .014"x.014" even when the aspect ratio isn't square. The pixel dimensions are always correct. Can't remember if it happened in earlier versions.
Preflight doesn't do any better:
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Thanks for the feedback everyone. So it looks like the general idea here is that Acrobat is misreporting the information on the image.
Question then: Is there another tool that I can use to better inspect properties of the PDF file?
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Question then: Is there another tool that I can use to better inspect properties of the PDF file?
The InDesign Link info is giving the correct resolution and pixel dimensions, so if the pixel dimensions in AcrobatPro are unchanged you have the resolution info over in ID's Links panel.
If the 1-bit image is converted to 8-bit grayscale Object Inspector will report the correct resolution. The output of the 1-bit to 8-bit conversion would be identical.
1-bit image
Same image to 8-bit reports the correct output dimensions and 150ppi res.:
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Also, it's really the output dimensions that are wrong. If I resize in Photoshop I can see Acrobat's reported resolution is correct relative to the misreported .014" output dimension:
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Thank you again for the helpful information.
Unfortunately, I sometimes get very specific and exacting specifications for the required output that I must abide by. One example, though not for this case, is FADGI. As I try to verify that my output meets the guidelines, I have to be able to demonstrate this to the file recipients and I have to feel confident it will pass whatever internal testing they will do. I am sure most of you have more experience in that area than I do.
And in this case, I don't believe that PDFs made with Acrobat and 1-bit monochrome bitmaps had the same resolution issue as ones made with InDesign (though I have not tested). This leaves an ambiguity that I'm not comfortable with. Another tool to check PDF contents would be great, but who do you trust if you don't trust Adobe?
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If you set the Monochrome Compression setting to Do Not Downsample and None 1-bit images would always export unchanged. If you or the client are bothered by the wrong dimension info in AcrobatPro start placing Black & White Grayscales.
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image height and width must be in millimeters and not in pixels
if in pixels then 72 dpi