How to Read Barcodes from Streams with C#

Why Use Memory Streams Instead of Files?

Memory streams offer several advantages over file-based operations. They eliminate disk I/O overhead, making applications faster. They increase security since sensitive barcode data never touches the disk. They also suit cloud environments where disk access is limited or expensive. Combined with IronBarcode's async and multithreading capabilities, you can process multiple streams concurrently for maximum performance.

This section shows how to use IronBarcode to read an image stream and multiple image streams stored in a List<MemoryStream>. The following code includes comments to explain the process:

What Types of Image Formats Are Supported?

IronBarcode supports multiple image formats when reading from streams: JPEG, PNG, GIF, TIFF, BMP, and SVG. This flexibility allows processing barcode images regardless of source format. For optimal results, use the barcode reader settings to fine-tune the reading process.

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

class BarcodeFromImageStream
{
    static void Main(string[] args)
    {
        // Create a list of MemoryStreams to store image streams
        List<MemoryStream> imageStreams = new List<MemoryStream>
        {
            // Example of adding an existing MemoryStream object to the list
            new MemoryStream(File.ReadAllBytes("example1.png")),
            new MemoryStream(File.ReadAllBytes("example2.png"))
        };

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

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

class BarcodeFromImageStream
{
    static void Main(string[] args)
    {
        // Create a list of MemoryStreams to store image streams
        List<MemoryStream> imageStreams = new List<MemoryStream>
        {
            // Example of adding an existing MemoryStream object to the list
            new MemoryStream(File.ReadAllBytes("example1.png")),
            new MemoryStream(File.ReadAllBytes("example2.png"))
        };

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

List<MemoryStream> list = new List<MemoryStream>();
list.Add(AnyBitmap.FromFile("image1.jpg").ToStream());
list.Add(AnyBitmap.FromFile("image2.jpg").ToStream());
list.Add(AnyBitmap.FromFile("image3.png").ToStream());

var myBarcode = BarcodeReader.Read(list);

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

Imports IronBarCode
Imports System
Imports System.Collections.Generic
Imports System.IO

Friend Class BarcodeFromImageStream
	Shared Sub Main(ByVal args() As String)
		' Create a list of MemoryStreams to store image streams
		Dim imageStreams As New List(Of MemoryStream) From {
			New MemoryStream(File.ReadAllBytes("example1.png")),
			New MemoryStream(File.ReadAllBytes("example2.png"))
		}

Dim IronBarCode As using
Using IronSoftware.Drawing
	Dim System As using
	Using System.Collections.Generic
		Using System.IO
			
			Dim list As New List(Of MemoryStream)()
			list.Add(AnyBitmap.FromFile("image1.jpg").ToStream())
			list.Add(AnyBitmap.FromFile("image2.jpg").ToStream())
			list.Add(AnyBitmap.FromFile("image3.png").ToStream())
			
			Dim myBarcode = BarcodeReader.Read(list)
			
			For Each barcode In myBarcode
				Console.WriteLine(barcode.ToString())
			Next barcode
		End Using
	End Using
End Using

How Do I Handle Multiple Image Streams?

The code above shows IronBarcode accepting a single MemoryStream object or a list of MemoryStream objects in the BarcodeReader.Read() method. The example converts image files into MemoryStream objects and reads barcodes directly from the streams.

When processing multiple streams, IronBarcode uses its reading speed options efficiently. Adjust reading speed based on your needs—whether requiring maximum accuracy or fastest processing time. For reading multiple barcodes from a single stream, IronBarcode automatically detects and returns all found barcodes.

For enhanced accuracy with imperfect or low-quality images in streams, apply image correction filters before processing. This improves barcode recognition rates significantly.

Why Use ReadPdf() Instead of Read()?

The ReadPdf() method optimizes specifically for PDF documents, offering advantages over the generic Read() method. It handles PDF-specific features like multi-page documents, vector graphics, and embedded images efficiently. The method processes all PDF pages automatically and handles various PDF formats and compression types. For comprehensive features, see the reading barcodes tutorial.

This section demonstrates using IronBarcode to read PDF document files as MemoryStream objects or lists of PDF document streams. Here's the code:

What About Multiple PDF Documents?

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

using IronBarCode;
using IronPdf;
using System;
using System.IO;

MemoryStream document = PdfDocument.FromFile(@"file_path.pdf").Stream;

var myBarcode = BarcodeReader.ReadPdf(document);

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

Imports IronBarCode
Imports IronPdf
Imports System
Imports System.IO

Private document As MemoryStream = PdfDocument.FromFile("file_path.pdf").Stream

Private myBarcode = BarcodeReader.ReadPdf(document)

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

How Do I Process Multiple PDF Streams Efficiently?

Reading barcodes from PDF documents as MemoryStream objects resembles reading from images. The key difference is the method: BarcodeReader.ReadPdf() specifically handles PDF documents. The example uses IronPDF to convert PDF documents to MemoryStream objects.

For multiple PDF documents, merge all PDFs into one document stream before feeding it to BarcodeReader.ReadPdf(). This approach processes more efficiently than handling each PDF separately and reduces memory overhead. Configure PDF-specific barcode reader settings to optimize reading for your documents.

For advanced scenarios, process specific pages or PDF regions. IronBarcode allows specifying page ranges and cropping regions within pages, targeting areas where barcodes appear. This improves processing speed for large documents.

When using streams in production, properly dispose of MemoryStream objects to prevent memory leaks. The using statement ensures automatic disposal:

using (MemoryStream pdfStream = new MemoryStream(pdfBytes))
{
    var results = BarcodeReader.ReadPdf(pdfStream);
    // Process results
}

using (MemoryStream pdfStream = new MemoryStream(pdfBytes))
{
    var results = BarcodeReader.ReadPdf(pdfStream);
    // Process results
}

Imports System.IO

Using pdfStream As New MemoryStream(pdfBytes)
    Dim results = BarcodeReader.ReadPdf(pdfStream)
    ' Process results
End Using

Experiment and adapt the library for your specific needs. IronBarcode's flexible API allows extensive reading process customization, from adjusting detection sensitivity to specifying expected barcode formats.