How to Read Barcodes From System.Drawing in C#

Which System.Drawing Types Can Be Cast?

:path=/static-assets/barcode/content-code-examples/how-to/read-barcodes-from-system-drawing-cast-to-anybitmap.cs

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

List<AnyBitmap> barcodes = new List<AnyBitmap>();

// Instantiate System.Drawing.Bitmap
System.Drawing.Bitmap bitmapFromBitmap = new System.Drawing.Bitmap("test1.jpg");

// Cast from System.Drawing.Bitmap to AnyBitmap
AnyBitmap barcode1 = bitmapFromBitmap;

barcodes.Add(barcode1);

// Instantiate System.Drawing.Bitmap
System.Drawing.Image bitmapFromFile = System.Drawing.Image.FromFile("test2.png");

// Cast from System.Drawing.Image to AnyBitmap
AnyBitmap barcode2 = bitmapFromFile;

barcodes.Add(barcode2);

Imports IronSoftware.Drawing
Imports System.Collections.Generic

Private barcodes As New List(Of AnyBitmap)()

' Instantiate System.Drawing.Bitmap
Private bitmapFromBitmap As New System.Drawing.Bitmap("test1.jpg")

' Cast from System.Drawing.Bitmap to AnyBitmap
Private barcode1 As AnyBitmap = bitmapFromBitmap

barcodes.Add(barcode1)

' Instantiate System.Drawing.Bitmap
Dim bitmapFromFile As System.Drawing.Image = System.Drawing.Image.FromFile("test2.png")

' Cast from System.Drawing.Image to AnyBitmap
Dim barcode2 As AnyBitmap = bitmapFromFile

barcodes.Add(barcode2)

This code demonstrates seamless integration between System.Drawing objects and IronBarcode through IronDrawing. This compatibility extends across various barcode formats, detailed in our supported barcode formats guide, including QR codes, Code 128, Code 39, and many others.

Why Does Implicit Casting Work?

In the code above, we loaded two barcode images as System.Drawing.Bitmap and System.Drawing.Image. We then implicitly cast them into AnyBitmap by assigning them to AnyBitmap objects, then added these objects to an AnyBitmap list.

IronDrawing's implicit casting mechanism uses operator overloading, providing transparent conversion between System.Drawing types and AnyBitmap. This design pattern lets developers maintain existing code while gaining cross-platform compatibility. The conversion preserves all image properties including resolution, color depth, and pixel data, ensuring no quality loss.

When Should I Use Explicit vs Implicit Casting?

While implicit casting provides convenience, explicit casting might be preferred in some scenarios:

// Implicit casting - clean and simple for straightforward conversions
System.Drawing.Bitmap systemBitmap = new System.Drawing.Bitmap("barcode.png");
AnyBitmap anyBitmap = systemBitmap; // Implicit cast

// Explicit casting - useful when type clarity is important
System.Drawing.Image systemImage = System.Drawing.Image.FromFile("qrcode.jpg");
AnyBitmap explicitBitmap = (AnyBitmap)systemImage; // Explicit cast

// When working with nullable types or conditional logic
System.Drawing.Bitmap? nullableBitmap = GetBitmapFromSource();
if (nullableBitmap != null)
{
    AnyBitmap result = (AnyBitmap)nullableBitmap; // Explicit cast for clarity
    // Process the barcode
}

// Implicit casting - clean and simple for straightforward conversions
System.Drawing.Bitmap systemBitmap = new System.Drawing.Bitmap("barcode.png");
AnyBitmap anyBitmap = systemBitmap; // Implicit cast

// Explicit casting - useful when type clarity is important
System.Drawing.Image systemImage = System.Drawing.Image.FromFile("qrcode.jpg");
AnyBitmap explicitBitmap = (AnyBitmap)systemImage; // Explicit cast

// When working with nullable types or conditional logic
System.Drawing.Bitmap? nullableBitmap = GetBitmapFromSource();
if (nullableBitmap != null)
{
    AnyBitmap result = (AnyBitmap)nullableBitmap; // Explicit cast for clarity
    // Process the barcode
}

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What Are Common Casting Errors?

When converting System.Drawing to AnyBitmap, developers might encounter:

1. Null Reference Exceptions: Verify your System.Drawing object isn't null before casting
2. Unsupported Format Exceptions: Some exotic image formats require pre-conversion
3. Memory Issues: Large images need proper disposal patterns

For troubleshooting casting issues, our troubleshooting guide provides solutions to common problems during barcode recognition.

What Methods Accept AnyBitmap Parameters?

:path=/static-assets/barcode/content-code-examples/how-to/read-barcodes-from-system-drawing-read-anybitmap.cs

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

List<AnyBitmap> barcodes = new List<AnyBitmap>();

System.Drawing.Bitmap bitmapFromBitmap = new System.Drawing.Bitmap("test1.jpg");
AnyBitmap barcode1 = bitmapFromBitmap;
barcodes.Add(barcode1);

System.Drawing.Image bitmapFromFile = System.Drawing.Image.FromFile("test2.png");
AnyBitmap barcode2 = bitmapFromFile;
barcodes.Add(barcode2);

foreach (var barcode in barcodes)
{
    // Read the barcode
    var results = BarcodeReader.Read(barcode);
    foreach (var result in results)
    {
        // Output the detected barcode value
        Console.WriteLine(result.Value);
    }
}

Imports IronBarCode
Imports IronSoftware.Drawing
Imports System
Imports System.Collections.Generic

Private barcodes As New List(Of AnyBitmap)()

Private bitmapFromBitmap As New System.Drawing.Bitmap("test1.jpg")
Private barcode1 As AnyBitmap = bitmapFromBitmap
barcodes.Add(barcode1)

Dim bitmapFromFile As System.Drawing.Image = System.Drawing.Image.FromFile("test2.png")
Dim barcode2 As AnyBitmap = bitmapFromFile
barcodes.Add(barcode2)

For Each barcode In barcodes
	' Read the barcode
	Dim results = BarcodeReader.Read(barcode)
	For Each result In results
		' Output the detected barcode value
		Console.WriteLine(result.Value)
	Next result
Next barcode

Beyond the basic Read method, IronBarcode provides several methods accepting AnyBitmap parameters. For advanced scenarios, see our guide on reading multiple barcodes demonstrating efficient processing of multiple barcodes in a single image:

// Advanced barcode reading with options
var readerOptions = new BarcodeReaderOptions
{
    // Specify barcode types to search for
    ExpectBarcodeTypes = BarcodeEncoding.QRCode | BarcodeEncoding.Code128,
    // Enable machine learning for better accuracy
    UseML = true,
    // Set confidence threshold
    Confidence = 0.95
};

// Read with specific options
var advancedResults = BarcodeReader.Read(anyBitmap, readerOptions);

// Advanced barcode reading with options
var readerOptions = new BarcodeReaderOptions
{
    // Specify barcode types to search for
    ExpectBarcodeTypes = BarcodeEncoding.QRCode | BarcodeEncoding.Code128,
    // Enable machine learning for better accuracy
    UseML = true,
    // Set confidence threshold
    Confidence = 0.95
};

// Read with specific options
var advancedResults = BarcodeReader.Read(anyBitmap, readerOptions);

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How Do I Handle Multiple Barcode Results?

The code above extends the previous example. After populating the AnyBitmap list, we iterated through it and called the Read method on each AnyBitmap object, which returned IronBarcode.BarcodeResults. We then iterated through the results to print barcode values to the console.

When handling multiple barcodes, leverage parallel processing for better performance:

// Parallel processing for multiple barcode images
var barcodeFiles = Directory.GetFiles("barcodes/", "*.png");
var allResults = new ConcurrentBag<BarcodeResult>();

Parallel.ForEach(barcodeFiles, file =>
{
    var bitmap = new System.Drawing.Bitmap(file);
    var anyBitmap = (AnyBitmap)bitmap;
    var results = BarcodeReader.Read(anyBitmap);

    foreach (var result in results)
    {
        allResults.Add(result);
    }

    bitmap.Dispose(); // Clean up resources
});

// Process all results
foreach (var result in allResults)
{
    Console.WriteLine($"Found {result.BarcodeType}: {result.Value}");
}

// Parallel processing for multiple barcode images
var barcodeFiles = Directory.GetFiles("barcodes/", "*.png");
var allResults = new ConcurrentBag<BarcodeResult>();

Parallel.ForEach(barcodeFiles, file =>
{
    var bitmap = new System.Drawing.Bitmap(file);
    var anyBitmap = (AnyBitmap)bitmap;
    var results = BarcodeReader.Read(anyBitmap);

    foreach (var result in results)
    {
        allResults.Add(result);
    }

    bitmap.Dispose(); // Clean up resources
});

// Process all results
foreach (var result in allResults)
{
    Console.WriteLine($"Found {result.BarcodeType}: {result.Value}");
}

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What Other IronDrawing Features Can I Use?

IronSoftware.Drawing functionality extends beyond casting images. It handles image processing aspects like colors and fonts useful for styling barcodes and QR codes. Explore how we utilize IronDrawing to customize and add logos to QR codes.

IronDrawing provides powerful image manipulation capabilities complementing barcode processing:

// Using IronDrawing for image preprocessing
using IronSoftware.Drawing;

// Load and preprocess an image before barcode reading
AnyBitmap preprocessedImage = AnyBitmap.FromFile("noisy-barcode.jpg");

// Apply image filters to improve barcode readability
preprocessedImage = preprocessedImage.ToGrayScale();
preprocessedImage = preprocessedImage.Contrast(1.5); // Increase contrast
preprocessedImage = preprocessedImage.Sharpen(); // Sharpen image

// Read the preprocessed barcode
var improvedResults = BarcodeReader.Read(preprocessedImage);

// Using IronDrawing for image preprocessing
using IronSoftware.Drawing;

// Load and preprocess an image before barcode reading
AnyBitmap preprocessedImage = AnyBitmap.FromFile("noisy-barcode.jpg");

// Apply image filters to improve barcode readability
preprocessedImage = preprocessedImage.ToGrayScale();
preprocessedImage = preprocessedImage.Contrast(1.5); // Increase contrast
preprocessedImage = preprocessedImage.Sharpen(); // Sharpen image

// Read the preprocessed barcode
var improvedResults = BarcodeReader.Read(preprocessedImage);

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For scenarios requiring specific image corrections, our image correction guide details using filters to enhance barcode readability.

Why Choose IronDrawing Over System.Drawing?

IronDrawing offers compelling advantages over System.Drawing:

1. Cross-Platform Support: Works seamlessly on Windows, Linux, and macOS unlike System.Drawing (Windows-only in .NET Core/5+)
2. Modern Architecture: Built on SkiaSharp and ImageSharp for better performance and memory management
3. Simplified API: Maintains familiar System.Drawing-like interfaces while adding modern conveniences
4. Active Development: Regular updates and improvements, unlike System.Drawing in maintenance mode
5. Better Integration: Designed specifically for optimal performance with IronSoftware products

For deployment considerations, especially for cloud environments, see our guides on deploying to Azure and deploying to AWS, which include specific notes about cross-platform compatibility using IronDrawing.

Whether building desktop applications, web services, or cloud-native solutions, IronDrawing ensures your barcode processing code remains portable and efficient across all platforms, making it the ideal choice for modern .NET development.