Existing PDF to PDF/A "conversion" - pdf

Question

I am trying to make an existing pdf into pdf/a-1b. I understand that itext cannot convert a pdf to pdf/a in the sense making it pdf/a compliant. But it definitely can flag the document as pdf/a. However, I looked at various examples and I cannot seem to figure out how to do it. The major problem is that
writer.PDFXConformance = PdfWriter.PDFA1B;
does not work anymore. First PDFA1B is not recognized, second, pdfwriter seems to have been rewritten and there is not much information about that.
It seems the only (in itext java version) way is:
PdfAWriter writer = PdfAWriter.getInstance(document, new FileOutputStream(filename), PdfAConformanceLevel.PDF_A_1B);
But that requires a document type, ie. it can be used when creating a pdf from scratch.
Can someone give an example of pdf to pdf/a conversion with the current version of itextsharp?
Thank you.

Answer 1

I can't imagine a valid reason for doing this but apparently you have one.
The conformance settings in iText are intended to be used with a PdfWriter and that object is (generally) only intended to be used with new documents. Since iText was never intended to convert documents to conformance that's just the way it was built.
To do what you want to do you could either just open the original document and update the appropriate tags in the document's dictionary or you could create a new document with the appropriate entries set and then import your old document. The below code shows the latter route, it first creates a regular non-conforming PDF and then creates a second document that says it is conforming even though it may or may not. See the code comments for more details. This targets iTextSharp 5.4.2.0.
//Folder that we're working from
var workingFolder = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);
//Create a regular non-conformant PDF, nothing special below
var RegularPdf = Path.Combine(workingFolder, "File1.pdf");
using (var fs = new FileStream(RegularPdf, FileMode.Create, FileAccess.Write, FileShare.None)) {
using (var doc = new Document()) {
using (var writer = PdfWriter.GetInstance(doc, fs)) {
doc.Open();
doc.Add(new Paragraph("Hello world!"));
doc.Close();
}
}
}
//Create our conformant document from the above file
var ConformantPdf = Path.Combine(workingFolder, "File2.pdf");
using (var fs = new FileStream(ConformantPdf, FileMode.Create, FileAccess.Write, FileShare.None)) {
using (var doc = new Document()) {
//Use PdfSmartCopy to get every page
using (var copy = new PdfSmartCopy(doc, fs)) {
//Set our conformance levels
copy.SetPdfVersion(PdfWriter.PDF_VERSION_1_3);
copy.PDFXConformance = PdfWriter.PDFX1A2001;
//Open our new document for writing
doc.Open();
//Bring in every page from the old PDF
using (var r = new PdfReader(RegularPdf)) {
for (var i = 1; i <= r.NumberOfPages; i++) {
copy.AddPage(copy.GetImportedPage(r, i));
}
}
//Close up
doc.Close();
}
}
}
Just to be 100% clear, this WILL NOT MAKE A CONFORMANT PDF, just a document that says it conforms.