Libdmtx.Net 0.7.9-dev

Libdmtx.Net — .NET 8/9 Data Matrix Wrapper

Community-maintained .NET wrapper for libdmtx, the open-source C library for encoding and decoding Data Matrix ECC200 barcodes. This is not an official package from the libdmtx project.

Features

• ✅ .NET 8 & .NET 9 support (cross-platform)
• ✅ No System.Drawing dependency — uses raw byte[] pixel data
• ✅ Encode text/bytes → Data Matrix barcode image
• ✅ Decode Data Matrix barcode image → text/bytes
• ✅ Modern C# API with nullable annotations

Quick Start

1. Build the native library

See native/BUILD.md for platform-specific instructions. After building, copy libdmtx.dll (or .so/.dylib) to your output directory.

2. Add the NuGet reference

<ProjectReference Include="path/to/src/Libdmtx.Net/Libdmtx.Net.csproj" />

3. Encode

using Libdmtx;

byte[] data = Encoding.ASCII.GetBytes("Hello World!");
EncodeResult result = Dmtx.Encode(data, new EncodeOptions
{
    ModuleSize = 5,
    MarginSize = 2,
});

// result.PixelData contains 24-bit BGR pixels
// result.Width, result.Height give image dimensions
SaveAsBmp(result.PixelData, result.Width, result.Height, "barcode.bmp");

4. Decode

using Libdmtx;

// Load image data as BGR24 byte array
byte[] imageData = File.ReadAllBytes("barcode.raw");
// ... or convert from Bitmap using LockBits ...

DecodeResult[] results = Dmtx.Decode(imageData, width, height, stride);

foreach (var r in results)
{
    string text = r.Text;  // auto-trims null padding
    Console.WriteLine($"Decoded: {text}");
}

Project Structure

dotnet/
├── src/Libdmtx.Net/          # Class library
│   ├── Dmtx.cs               # Main entry point (static API)
│   ├── DmtxImage.cs          # Native image handle wrapper
│   ├── DmtxException.cs      # Custom exceptions
│   ├── Options/              # Encode/Decode options
│   ├── Results/              # Encode/Decode results
│   └── Interop/              
│       ├── NativeMethods.cs  # DllImport declarations
│       ├── NativeEnums.cs    # C# enums matching libdmtx defines
│       └── NativeStructs.cs  # C# structs for native types
├── samples/Libdmtx.Demo/     # Console demo app
└── native/BUILD.md           # Native library build guide

API Overview

Dmtx.Encode(byte[] data, EncodeOptions? options)

Encodes data into a Data Matrix barcode. Returns EncodeResult with raw pixel data.

Dmtx.EncodeString(string text, EncodeOptions? options)

Shorthand for encoding ASCII text.

Dmtx.Decode(byte[] pixelData, int width, int height, int stride, DecodeOptions? options)

Decodes one or more Data Matrix symbols from a BGR24 image.

Dmtx.Version

Returns the native libdmtx version string, or null if the library isn't loaded.

Notes

• The library expects 24-bit BGR pixel data (matching libdmtx's native format).
• Input pixel data must remain pinned/rooted during decoding — the wrapper handles this.
• The native DLL must be placed where the runtime can find it (same directory as the .exe, or system PATH).

License

The C# wrapper code in this package is licensed under BSD-2-Clause.

The bundled native library is Copyright © Mike Laughton, Vadim A. Misbakh-Soloviov and others, used under the BSD-2-Clause license (see the libdmtx LICENSE file for full terms).

This is a community-maintained package, not an official libdmtx release.