Set PDF Version using iTextSharp

Question

Anyone know how to save a PDF as a lower PDF version programmatically using iTextSharp so that you can use certain iTextSharp features that require the PDF to be version 5 o

Answer 1

How odd. PDF versions are mostly a suggestion. PDFs must start with something like:

%PDF-1.x

Where the X is 0,1,2,...

This is just a clue to the app reading the PDF. The only clue. Most "I need version X" requests I see from various customers are bogus. My fellow iText coders know this, so it strikes me as odd that iText is requesting a different version.

You're sure its iText requesting v5?

At any rate, to answer your question:

Yes, iText can change the version number of a PDF. Sadly, it can only be done when writing out a PDF, not when reading it in. You'll have to open the PDF, change its version, and save it again.

You could probably cheat. Read the PDFs into byte arrays and pdfBytes[7] = 4;, then pass those bytes on to a PdfReader.

Version 1 of the PDF spec is 1.0 Version 2 is 1.1 ...

So if you want pdf version 5, you need to write out "1.4", not "1.5".

If you're not comfortable poking a byte like that, you can parse the whole PDF, change the version, then write it all out again:

 PdfReader reader = new PdfReader(pdfPath);
 PdfStamper stamper = new PdfStamper(reader, outputStream);
 stamper.setPdfVersion(PdfWriter.PDF_VERSION_1_4);
 stamper.close();

You'd then read it in again, and combine it as you have been.