qrcode

go-pkg-qrcode

A powerful Go package for generating QR codes with advanced customization options including gradient effects, logo embedding, and flexible styling.

🚀 Features

• Advanced Customization: Colors, gradients, borders, and sizing options
• Logo Embedding: Automatic logo download and embedding with size control
• Gradient Effects: Linear and radial gradient support for QR codes
• Error Correction: Configurable error correction levels (L, M, Q, H)
• Flexible Sizing: Customizable QR code dimensions
• Color Support: RGB, RGBA, and named color formats
• Border Control: Configurable border width and disable options
• High Performance: Fast QR code generation with optimized image processing

📦 Installation

go get github.com/kerimovok/go-pkg-qrcode

📖 Quick Start

package main

import (
    "os"
    "github.com/kerimovok/go-pkg-qrcode"
)

func main() {
    // Generate a basic QR code
    png, err := qrcode.GeneratePNG(qrcode.Options{
        Data: "https://example.com",
        Size: 300,
    })
    if err != nil {
        panic(err)
    }
    
    os.WriteFile("qrcode.png", png, 0644)
}

🎯 Usage

Basic Usage

import "github.com/kerimovok/go-pkg-qrcode"

// Simple function call
png, err := qrcode.GeneratePNG(qrcode.Options{
    Data: "https://example.com",
    Size: 300,
})

Using Generator Instance

generator := qrcode.New()

png, err := generator.GeneratePNG(qrcode.Options{
    Data: "https://example.com",
    Size: 300,
})

Customized QR Code

png, err := qrcode.GeneratePNG(qrcode.Options{
    Data:       "https://example.com",
    Size:       400,
    Foreground: "rgb(0,100,200)",
    Background: "rgb(240,240,240)",
    Error:      "H",
    Border:     8,
})

QR Code with Gradient

png, err := qrcode.GeneratePNG(qrcode.Options{
    Data:         "https://example.com",
    Size:         400,
    GradientStart: "rgb(255,0,0)",
    GradientEnd:   "rgb(0,0,255)",
    GradientType:  "linear", // or "radial"
    Error:        "H",
})

QR Code with Logo

png, err := qrcode.GeneratePNG(qrcode.Options{
    Data:     "https://example.com",
    Size:     500,
    LogoURL:  "https://example.com/logo.png",
    LogoSize: 25.0, // percentage of QR code size
    Error:    "H",
})

⚙️ Options

Options Struct

type Options struct {
    // Data is the content to encode in the QR code (required)
    Data string

    // Size is the QR code dimensions in pixels (default: 300)
    Size int

    // Foreground is the foreground color (QR code pattern)
    // Supports: rgb(r,g,b), rgba(r,g,b,a), or named colors
    // Default: black
    Foreground string

    // Background is the background color
    // Supports: rgb(r,g,b), rgba(r,g,b,a), or named colors
    // Default: white
    Background string

    // Error is the error correction level: L, M, Q, H
    // Default: M
    Error string

    // Border is the border width in pixels (0 = no border)
    // Default: 0
    Border int

    // LogoURL is the URL to a logo image to embed
    LogoURL string

    // LogoSize is the logo size as a percentage (default: 20.0)
    LogoSize float64

    // GradientStart is the start color for gradient effect
    GradientStart string

    // GradientEnd is the end color for gradient effect
    GradientEnd string

    // GradientType is the type of gradient: "linear" or "radial"
    GradientType string
}

Color Formats

The package supports multiple color formats:

• RGB: rgb(255,0,0)
• RGBA: rgba(255,0,0,128)
• Named Colors: black, white, red, green, blue

Error Correction Levels

Gradient Types

• linear: Horizontal gradient from start to end color
• radial: Circular gradient from center outward

📚 Examples

Example 1: Basic QR Code

png, err := qrcode.GeneratePNG(qrcode.Options{
    Data: "https://example.com",
    Size: 300,
})

Example 2: Customized QR Code

png, err := qrcode.GeneratePNG(qrcode.Options{
    Data:       "https://example.com",
    Size:       400,
    Foreground: "rgb(0,100,200)",
    Background: "rgb(240,240,240)",
    Error:      "H",
    Border:     8,
})

Example 3: QR Code with Gradient

png, err := qrcode.GeneratePNG(qrcode.Options{
    Data:         "https://example.com",
    Size:         400,
    GradientStart: "rgb(255,0,0)",
    GradientEnd:   "rgb(0,0,255)",
    GradientType:  "radial",
    Error:        "Q",
})

Example 4: QR Code with Logo

png, err := qrcode.GeneratePNG(qrcode.Options{
    Data:     "https://example.com",
    Size:     500,
    LogoURL:  "https://example.com/logo.png",
    LogoSize: 30.0,
    Error:    "H",
})

Example 5: Complex QR Code

png, err := qrcode.GeneratePNG(qrcode.Options{
    Data:         "https://example.com",
    Size:         600,
    Foreground:    "rgb(50,50,50)",
    Background:    "rgb(250,250,250)",
    GradientStart: "rgb(100,200,255)",
    GradientEnd:   "rgb(255,100,200)",
    GradientType:  "linear",
    LogoURL:       "https://example.com/logo.png",
    LogoSize:      20.0,
    Error:         "H",
    Border:        12,
})

🔧 API Reference

Functions

GeneratePNG(opts Options) ([]byte, error)

Convenience function that creates a generator and generates a QR code.

Returns: PNG image byte array and error

New() *Generator

Creates a new QR code generator instance.

Methods

(*Generator) GeneratePNG(opts Options) ([]byte, error)

Generates a QR code as a PNG image byte array.

Returns: PNG image byte array and error

🛠️ Dependencies

• github.com/skip2/go-qrcode - QR code generation
• github.com/disintegration/imaging - Image processing

📝 License

[Your License Here]

🤝 Contributing

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

🙏 Acknowledgments

• Built on top of go-qrcode for QR code generation
• Uses imaging for high-quality image processing
• Designed for production reliability and developer experience

Note: This package requires Go 1.25 or later.