Removing text from a PDF

[Precision999]

Hi

I have a pdf file from a client with name and address details on the odd pages (it's a file of postcards which are 2 sided, could be several hundred pages long).

I need to take a copy of one of the postcards (2 pages), remove the existing address and add a different one. The idea is to have a copy go to a seed address for quality control purposes.

What I've done so far is lay a white square graphic over the top of the existing text (it's in a consistent area) then, using itextsharp, stamp the new address over the top. I finally append this 'new' pdf on the end of the existing file.

So far so good, but the old address is still there, so when I do a text extract from the pdf it gets a bit confused on this record because there are effectively 2 addresses mixed up, even though only the one I want is visible.

Can anyone suggest a way I could make the white area stamp process remove the text, instead of just covering it visually?

I'm open to other suggestions as to how to tackle this!

Thanks for reading

[Precision999]

From a bit more research it looks like redacting the existing address area might be the way to go (then stamping the new address on top).

If I have any joy with this I'll post details in case it helps someone.

[Precision999]

Sorry to keep replying to my own post, but I've found what looks to be the answer in the link below, I just need a bit of help with the final stage:

https://itextpdf.com/en/resources/fa...ply-redactions


I currently have the following (I've converted from c# used in link above to vb):

Imports iTextSharp.text.pdf
Imports System.IO
Imports iTextSharp.xtra.iTextSharp.text.pdf.pdfcleanup


Public Class Form1

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        Dim FileName = "C:\test redact\sample.pdf"
        Dim newFileName = "C:\test redact\redact marked.pdf"

        ' Mark area to redact with rectangle


        Using stream As Stream = New FileStream(FileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)
            Dim pdfReader As New PdfReader(stream)
            Using stamper As New PdfStamper(pdfReader, New FileStream(newFileName, FileMode.OpenOrCreate))

                Dim page As Integer = 2
                Dim rect As New iTextSharp.text.Rectangle(620, 220, 370, 350)
                Dim annotation As New PdfAnnotation(stamper.Writer, rect)
                annotation.Put(PdfName.SUBTYPE, New PdfName("Redact"))
                annotation.Title = "My Author"
                annotation.Put(New PdfName("Subj"), New PdfName("Redact"))
                Dim fillColor As Single() = {0, 0, 0}
                annotation.Put(New PdfName("IC"), New PdfArray(fillColor))
                Dim fillColorRed As Single() = {1, 0, 0}
                annotation.Put(New PdfName("OC"), New PdfArray(fillColorRed))
                stamper.AddAnnotation(annotation, page)

            End Using

        End Using



        ' Now redact the marked area

        Dim src = newFileName
        Dim dest = "C:\test redact\redact FINAL.pdf"

        Dim reader2 = New PdfReader(New FileStream(src, FileMode.Open))

        'Dim stamper2 As New PdfStamper(reader2, New FileOutputStream(dest))

        Dim stamper2 = New PdfStamper(reader2, New FileStream(dest, FileMode.Create))

        Dim cleaner As New PdfCleanUpProcessor(stamper2)

        cleaner.CleanUp()
        stamper2.Close()
        reader2.Close()

        ' open the results to have a look

        Process.Start("C:\test redact\redact FINAL.pdf")
        Application.Exit()

    End Sub


End Class

With this code the 'marking up' section is OK and produces an outline on page 2 of my pdf in the area I want.

The problem is I get the error System.NullReferenceException: 'Object reference not set to an instance of an object.' on this line:

Dim cleaner As New PdfCleanUpProcessor(stamper2)

As part of getting this to work I had to replace this line:

 'Dim stamper2 As New PdfStamper(reader2, New FileOutputStream(dest))

with this one:

Dim stamper2 = New PdfStamper(reader2, New FileStream(dest, FileMode.Create))

Also - probably most important - the original link mentions the process 'requires the itext-xtra.jar'. I've downloaded this file but I don't know how to use it? I'm afraid I know nothing about java.

Can anyone give me some help please?

Thanks!