Adding accessibility information to a PDF

[bencyoung-Fignum]

I'm trying to use PdfPig to add some metadata to an existing PDF. The PDF has fairly good accessibility but fails the checker for metadata reasons:

So I'm using the merge example to try and take the existing PDF and add the metadata

using var existing = PdfDocument.Open("htmlTest.pdf");

using var output = File.OpenWrite(htmlTest2.pdf");
using var created = new PdfDocumentBuilder(output, false, PdfWriterType.Default);

created.ArchiveStandard = PdfAStandard.None;

created.IncludeDocumentInformation = true;
created.DocumentInformation.Title = "A test title";
created.DocumentInformation.Creator = "Ben";
created.DocumentInformation.Subject = "A test subject";
created.DocumentInformation.Keywords = "test, pdf, pig, example";
created.DocumentInformation.Author = "Ben";
created.DocumentInformation.Producer = "Producer";
created.DocumentInformation.CreationDate = DateTime.Now.Date.ToString("yyyy-MM-dd");

created.XmpMetadata = XDocument.Parse("""
    <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="Adobe XMP Core 9.1-c001 79.2a0d8d9, 2023/03/14-11:19:46        ">
       <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
          <rdf:Description rdf:about=""
                xmlns:dc="http://purl.org/dc/elements/1.1/"
                xmlns:xmp="http://ns.adobe.com/xap/1.0/"
                xmlns:xmpMM="http://ns.adobe.com/xap/1.0/mm/">
             <dc:format>application/pdf</dc:format>
             <dc:title>
                <rdf:Alt>
                   <rdf:li xml:lang="x-default">Vendor Report: VENDOR NAME</rdf:li>
                </rdf:Alt>
             </dc:title>
             <xmp:ModifyDate>2023-05-26T13:40:11-04:00</xmp:ModifyDate>
             <xmp:CreateDate>2023-05-26T13:40:11-04:00</xmp:CreateDate>
             <xmp:MetadataDate>2023-05-26T13:40:11-04:00</xmp:MetadataDate>
             <xmpMM:DocumentID>uuid:befe056c-5bfe-4c4d-9d90-0d6b1d008200</xmpMM:DocumentID>
             <xmpMM:InstanceID>uuid:580f188e-cc85-be41-bc8d-a82bdfe70206</xmpMM:InstanceID>
          </rdf:Description>
       </rdf:RDF>
    </x:xmpmeta>
    """);

foreach (var page in existing.GetPages())
{
    created.AddPage(existing, page.Number);
}

Which runs, but the roundtrip seems to have made things worse!

Has anyone managed to get something like this working, or is there a sub-part of PdfPig I may be able to use to try and implement this manually?

[EliotJones]

What tool are you using to pull this report out of interest?

I suspect this is because when we call AddPage we only copy PDF elements related to that page, not the non-page document level elements that are also important to accessibility. This is also causing a couple of other bugs in the backlog related to annotations. I don't think it's going to be possible to rework this without a radical redesign of document creation.