Tagged PDF: Adding Alt to the Structure Tree
addalttags
AddAltTags Java
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.tagging;
import com.itextpdf.kernel.pdf.PdfArray;
import com.itextpdf.kernel.pdf.PdfDictionary;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfName;
import com.itextpdf.kernel.pdf.PdfReader;
import com.itextpdf.kernel.pdf.PdfString;
import com.itextpdf.kernel.pdf.PdfWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
public class AddAltTags {
public static final String DEST = "./target/sandbox/tagging/add_alt_tags.pdf";
public static final String SRC = "./src/main/resources/pdfs/no_alt_attribute.pdf";
public static void main(String[] args) throws Exception {
File file = new File(DEST);
file.getParentFile().mkdirs();
new AddAltTags().manipulatePdf(DEST);
}
public void manipulatePdf(String dest) throws IOException {
PdfDocument pdfDoc = new PdfDocument(new PdfReader(SRC), new PdfWriter(dest));
PdfDictionary catalog = pdfDoc.getCatalog().getPdfObject();
// Gets the root dictionary
PdfDictionary structTreeRoot = catalog.getAsDictionary(PdfName.StructTreeRoot);
manipulate(structTreeRoot);
pdfDoc.close();
}
public void manipulate(PdfDictionary element) {
if (element == null) {
return;
}
// If an element is a figure, adds an /Alt entry.
if (PdfName.Figure.equals(element.get(PdfName.S))) {
element.put(PdfName.Alt, new PdfString("Figure without an Alt description"));
}
PdfArray kids = element.getAsArray(PdfName.K);
if (kids == null) {
return;
}
// Loops over all the kids
for (int i = 0; i < kids.size(); i++) {
manipulate(kids.getAsDictionary(i));
}
}
}
AddAltTags C#
C#
using System;
using System.IO;
using iText.Kernel.Pdf;
namespace iText.Samples.Sandbox.Tagging
{
public class AddAltTags
{
public static readonly string DEST = "results/sandbox/tagging/add_alt_tags.pdf";
public static readonly String SRC = "../../../resources/pdfs/no_alt_attribute.pdf";
public static void Main(String[] args)
{
FileInfo file = new FileInfo(DEST);
file.Directory.Create();
new AddAltTags().ManipulatePdf(DEST);
}
private void ManipulatePdf(String dest)
{
PdfDocument pdfDoc = new PdfDocument(new PdfReader(SRC), new PdfWriter(dest));
PdfDictionary catalog = pdfDoc.GetCatalog().GetPdfObject();
// Gets the root dictionary
PdfDictionary structTreeRoot = catalog.GetAsDictionary(PdfName.StructTreeRoot);
Manipulate(structTreeRoot);
pdfDoc.Close();
}
private void Manipulate(PdfDictionary element)
{
if (element == null)
{
return;
}
// If an element is a figure, adds an /Alt entry.
if (PdfName.Figure.Equals(element.Get(PdfName.S)))
{
element.Put(PdfName.Alt, new PdfString("Figure without an Alt description"));
}
PdfArray kids = element.GetAsArray(PdfName.K);
if (kids == null)
{
return;
}
// Loops over all the kids
for (int i = 0; i < kids.Size(); i++)
{
Manipulate(kids.GetAsDictionary(i));
}
}
}
}