How to Read Barcodes from PDF in C#

What Are the Basic Steps to Read PDF Barcodes?

1. Install the barcode library to process barcode files. Check our NuGet Packages guide for platform-specific installation.
2. Create PdfBarcodeReaderOptions if required.
3. Use the ReadPdf method from BarcodeReader to read barcodes from PDFs.
4. Specify additional barcode reading options using BarcodeReaderOption.
5. Extract barcode values.

How Do I Read Barcodes from PDF Documents Directly?

IronBarcode reads barcodes directly from PDF documents without requiring conversion to images. For a comprehensive overview of all features, visit our Features page. Use the BarcodeReader.ReadPdf() method, which accepts these PDF input types:

• byte[] array: PDF document as a byte array.
• IEnumerable<Byte[]>: PDF documents as byte arrays stored in a collection.
• MemoryStream: PDF documents as MemoryStream type.
• IEnumerable<Stream>: PDF documents as a collection of MemoryStream. See our Read Barcode from Streams guide.
• String: PDF document path as a string or filename if copied into the project.
• IEnumerable<String>: PDF document path/name strings stored in a collection.

The BarcodeReader.ReadPdf() method also accepts PdfBarcodeReaderOptions for advanced reading capabilities, discussed in the next section. Here's how to use BarcodeReader.ReadPdf() to read barcodes in PDF documents:

:path=/static-assets/barcode/content-code-examples/how-to/read-barcodes-from-pdf-1.cs

using IronBarCode;
using System;
using System.Collections.Generic;

List<String> docs = new List<String>();
docs.Add(@"pdf_a.pdf");
docs.Add(@"pdf_b.pdf");

var myBarcode = BarcodeReader.ReadPdfs(docs);   //can also accept individual PDF document file path as argument

foreach (var value in myBarcode)
{
    Console.WriteLine(value.ToString());
}

Imports IronBarCode
Imports System
Imports System.Collections.Generic

Private docs As New List(Of String)()
docs.Add("pdf_a.pdf")
docs.Add("pdf_b.pdf")

Dim myBarcode = BarcodeReader.ReadPdfs(docs) 'can also accept individual PDF document file path as argument

For Each value In myBarcode
	Console.WriteLine(value.ToString())
Next value

Pass the PDF file path string to BarcodeReader.ReadPdf() to read barcode values. For more examples on reading barcodes from different sources, check our Reading Barcodes in C# / .NET tutorial. To print all barcode values found in the PDF, iterate through the results using a foreach loop and call ToString() on each element. This example also demonstrates using a collection of PDF document names as the method argument.

:path=/static-assets/barcode/content-code-examples/how-to/read-barcodes-from-pdf-read-from-multiple-pdf.cs

using IronBarCode;
using System;
using System.Collections.Generic;
using System.IO;

// Get all PDF files from a directory and add to list
string folderPath = @"PATH_TO_YOUR_FOLDER";
List<string> docs = new List<string>(Directory.GetFiles(folderPath, "*.pdf"));

// Read barcodes from all PDFs
var docResult = BarcodeReader.ReadPdfs(docs);

// Print results
foreach (var doc in docResult)
{
    foreach (var item in doc)
    {
        Console.WriteLine("Barcode " + item.ToString() + " found at page " + item.PageNumber);
    }
}

IRON VB CONVERTER ERROR developers@ironsoftware.com

How Do I Configure PDF Barcode Reader Options?

Configure barcode reading from PDFs using PdfBarcodeReaderOptions. For a detailed explanation of all reader settings, visit our Set PDF Barcode Reader Options example. Adjusting these properties improves quality, accuracy, and performance. PdfBarcodeReaderOptions inherits all BarcodeReaderOptions properties and adds PDF-specific options. Specify page numbers when instantiating PdfBarcodeReaderOptions:

:path=/static-assets/barcode/content-code-examples/how-to/read-barcodes-from-pdf-2.cs

using IronBarCode;
using System.Collections.Generic;

List<int> pageNumber = new List<int>() { 1, 2, 3 };

PdfBarcodeReaderOptions PdfOptions = new PdfBarcodeReaderOptions(pageNumber)  // can also use individual page number as argument
{
    // Properties of PDF Barcode reader options
};

Imports IronBarCode
Imports System.Collections.Generic

Private pageNumber As New List(Of Integer)() From {1, 2, 3}

Private PdfOptions As New PdfBarcodeReaderOptions(pageNumber)

Explore the additional properties available in PdfBarcodeReaderOptions beyond those inherited from BarcodeReaderOptions.

How Do I Implement Advanced Barcode Reading from PDFs?

Apply PdfBarcodeReaderOptions properties in your project to enhance barcode reading from PDF documents. For additional troubleshooting tips when barcodes aren't recognized, refer to our Barcode Not Recognized guide.

:path=/static-assets/barcode/content-code-examples/how-to/read-barcodes-from-pdf-3.cs

using IronBarCode;
using System;
using System.Collections.Generic;

List<int> pageNumber = new List<int>() { 1, 2, 3 };

PdfBarcodeReaderOptions PdfOptions = new PdfBarcodeReaderOptions(pageNumber)
{
    DPI = 150,
    //PageNumbers = pageNumber,      //this property is not needed if page numbers has been specified as the argument in PdfBarcodeReaderOptions
    Password = "barcode",
    Scale = 3.5,
    //properties below are some of the properties inherited from BarcodeReaderOptions
    Speed = ReadingSpeed.Detailed,
    ExpectBarcodeTypes = BarcodeEncoding.Code93,
    ExpectMultipleBarcodes = true
};

var myBarcode = BarcodeReader.ReadPdf(@"pdf_a_filepath.pdf", PdfOptions);
foreach (var value in myBarcode)
{
    Console.WriteLine(value.ToString());
}

Imports IronBarCode
Imports System
Imports System.Collections.Generic

Private pageNumber As New List(Of Integer)() From {1, 2, 3}

Private PdfOptions As New PdfBarcodeReaderOptions(pageNumber) With {
	.DPI = 150,
	.Password = "barcode",
	.Scale = 3.5,
	.Speed = ReadingSpeed.Detailed,
	.ExpectBarcodeTypes = BarcodeEncoding.Code93,
	.ExpectMultipleBarcodes = True
}

Private myBarcode = BarcodeReader.ReadPdf("pdf_a_filepath.pdf", PdfOptions)
For Each value In myBarcode
	Console.WriteLine(value.ToString())
Next value

Initialize PdfBarcodeReaderOptions with a variable name to access and adjust properties. Pass page numbers as an argument during initialization to apply settings to specific pages. Alternatively, set page numbers using the PageNumbers property.

Use inherited BarcodeReaderOptions properties like ExpectMultipleBarcodes and ExpectBarcodeTypes to improve performance and accuracy. Apply configured PdfBarcodeReaderOptions by passing it as the second argument to BarcodeReader.ReadPdf(), with the PDF file path as the first argument.

For processing PDFs with imperfect or damaged barcodes, explore our Image Correction features that can be applied during PDF processing.