ESCPOS_NET.SkiaSharp 4.0.2

ESCPOS_NET.SkiaSharp

This is a fork of ESCPOS_NET by Luke Paireepinart and contributors. All credit for the library goes to the original project. This fork only replaces the image-processing dependency. Original package: ESCPOS_NET on NuGet · Original documentation: github.com/lukevp/ESC-POS-.NET

ESCPOS_NET is an easy to use, cross-platform .NET Standard 2.0 library for the ESC/POS protocol used by thermal receipt printers, line displays and cash drawers. It works with Serial, USB, Ethernet, WiFi and Bluetooth printers.

Why this fork?

ESCPOS_NET 3.0.0 (the latest upstream release) depends on SixLabors.ImageSharp 2.1.3, which has several known security vulnerabilities. Upgrading ImageSharp is not an option for many projects:

• Pinning ImageSharp 3.x breaks image printing: ESCPOS_NET is compiled against 2.x and PrintImage throws MissingMethodException (Image.Load(Byte[])).
• ImageSharp 3.x uses the Six Labors Split License instead of Apache 2.0 and no longer supports .NET Standard 2.0.

This fork replaces ImageSharp with SkiaSharp (MIT). Everything else is the upstream code.

Installation

dotnet add package ESCPOS_NET.SkiaSharp

It is a drop-in replacement: namespaces, assembly name and APIs are the same, so you only swap the package reference. Remove ESCPOS_NET when you add this package. Referencing both causes duplicate type conflicts.

Quick start

using ESCPOS_NET;
using ESCPOS_NET.Emitters;
using ESCPOS_NET.Utilities;

var printer = new ImmediateNetworkPrinter(new ImmediateNetworkPrinterSettings
{
    ConnectionString = "192.168.1.50:9100",
    PrinterName = "TestPrinter",
});

var e = new EPSON();
await printer.WriteAsync(
    ByteSplicer.Combine(
        e.CenterAlign(),
        e.PrintImage(File.ReadAllBytes("logo.png"), isHiDPI: true, maxWidth: 384),
        e.PrintLine("Thank you!"),
        e.FullCut()));

See the original documentation for printers, status events, encodings, barcodes and everything else.

Image printing

PrintImage / BufferImage accept encoded image bytes (PNG, JPEG, BMP, GIF, WebP, ...). The image is scaled to maxWidth (aspect ratio preserved), transparent areas become white, and it is converted to black and white with Stucki dithering, the same pipeline as upstream.

The 1-bit conversion is also available directly:

using ESCPOS_NET.Extensions;

SingleBitImage img = ImageRasterizer.ToSingleBitImage(pngBytes, maxWidth: 384, threshold: 0.5f);
// img.Width, img.Height, img.Data (1 bit per pixel, MSB first, rows padded to whole bytes)

Platforms

SkiaSharp uses a native library. This package brings everything needed:

• Windows (x86, x64, arm64) and macOS (Intel and Apple Silicon): included with SkiaSharp.
• Linux (glibc and musl/Alpine; x64, arm, arm64): included through SkiaSharp.NativeAssets.Linux.NoDependencies, which needs no fontconfig, so it works in slim containers.

If your application also references SkiaSharp.NativeAssets.Linux (for example through Avalonia), make sure its version matches the resolved SkiaSharp version. Otherwise SkiaSharp fails at startup on Linux with "The version of the native libSkiaSharp library is incompatible".

Breaking changes compared to ESCPOS_NET 3.0.0

• The public SixLabors.ImageSharp.ImageSharpExtensions.ToSingleBitPixelByteArray extension was removed. Use ESCPOS_NET.Extensions.ImageRasterizer.ToSingleBitImage instead.
• Printed images may differ in individual dots from ImageSharp's output (same size and tone, slightly different dither pattern).

License and credits

MIT, the same as the original project. Copyright (c) 2019 Luke Paireepinart, (c) 2022 CandL Development, LLC, with SkiaSharp changes (c) 2026 Valentin Huber.

The library itself is the work of the ESCPOS_NET contributors. Please report issues with the image printing in this fork and everything else in the original project.