Remove digital signatures

JAVA

/*
    This file is part of the iText (R) project.
    Copyright (c) 1998-2023 Apryse Group NV
    Authors: Apryse Software.

    For more information, please contact iText Software at this address:
    sales@itextpdf.com
 */
package com.itextpdf.samples.sandbox.acroforms;

import com.itextpdf.forms.fields.PdfFormCreator;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfReader;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.forms.PdfAcroForm;

import java.io.File;

public class FlattenSignature {
    public static final String DEST = "./target/sandbox/acroforms/flatten_signature.pdf";
    public static final String SRC = "./src/main/resources/pdfs/input_signed.pdf";

    public static void main(String[] args) throws Exception {
        File file = new File(DEST);
        file.getParentFile().mkdirs();

        new FlattenSignature().manipulatePdf(DEST);
    }

    protected void manipulatePdf(String dest) throws Exception {
        PdfDocument pdfDoc = new PdfDocument(new PdfReader(SRC), new PdfWriter(dest));
        PdfAcroForm form = PdfFormCreator.getAcroForm(pdfDoc, true);

        // If no fields have been explicitly included, then all fields are flattened.
        // Otherwise only the included fields are flattened.
        form.flattenFields();

        pdfDoc.close();
    }
}

C#

using System;
using System.IO;
using iText.Forms;
using iText.Forms.Fields;
using iText.Kernel.Pdf;

namespace iText.Samples.Sandbox.Acroforms
{
    public class FlattenSignature
    {
        public static readonly String DEST = "results/sandbox/acroforms/flatten_signature.pdf";

        public static readonly String SRC = "../../../resources/pdfs/input_signed.pdf";

        public static void Main(String[] args)
        {
            FileInfo file = new FileInfo(DEST);
            file.Directory.Create();

            new FlattenSignature().ManipulatePdf(DEST);
        }

        protected void ManipulatePdf(String dest)
        {
            PdfDocument pdfDoc = new PdfDocument(new PdfReader(SRC), new PdfWriter(dest));
            PdfAcroForm form = PdfFormCreator.GetAcroForm(pdfDoc, true);

            // If no fields have been explicitly included, then all fields are flattened.
            // Otherwise only the included fields are flattened.
            form.FlattenFields();

            pdfDoc.Close();
        }
    }
}