ExifTool Forum

ExifTool => The "exiftool" Application => Topic started by: ww23 on January 13, 2023, 11:44:55 PM

Title: Writing XMP metadata to PDF breaks PDF/A specification
Post by: ww23 on January 13, 2023, 11:44:55 PM
After modifying the XMP metadata of a PDF/A-3b file with
exiftool -XMP-pdf:Producer="Producer" Test.pdfthe preflight in Adobe Acrobat complains that the document doesn't conform to PDF/A-3b.
The original file was ok.
How can I modify XMP metadata while still preserving the PDF/A-3b standard?

Maybe this is relevant:
Producer
If the Producer entry (of PDF data type text string) is present in the document information dictionary, the document's Metadata must contain an equivalent en- try pdf:Producer of XMP data type AgentName where pdf refers to the Adobe PDF schema (the prefix is actually arbitrary).
(Link (https://www.pdfa.org/wp-content/uploads/2011/08/tn0003_metadata_in_pdfa-1_2008-03-182.pdf#page=6))
Title: Re: Writing XMP metadata to PDF breaks PDF/A specification
Post by: Phil Harvey on January 14, 2023, 08:17:45 AM
Your reference is not relevant since you are writing XMP:Producer and not PDF:Producer.

I suspect that the PDF/A-3b verifier may not like a PDF with an incremental update (although I can't verify this with a quick Google search), or possibly the PDF needs to be linearized.  Either way, you would have to run qpdf (or some other utility) to linearize the PDF and combine the incremental update after writing with ExifTool.

- Phil
Title: Re: Writing XMP metadata to PDF breaks PDF/A specification
Post by: StarGeek on January 15, 2023, 11:52:44 AM
Quote from: Phil Harvey on January 14, 2023, 08:17:45 AMI suspect that the PDF/A-3b verifier may not like a PDF with an incremental update (although I can't verify this with a quick Google search)

I did a more extensive google search when this question first popped up and couldn't verify it either.

Here's (https://www.debenu.com/kb/incremental-updates/) a page which describes the incremental update procedure.