gqr

gqr

gqr is a QR code generation library focused on creating customizable QR codes.

This project is a fork of github.com/yeqown/go-qrcode with updated API (see Changes) So big thanks to the initial project! 🙏

Features

Features marked with * are inherited from go-qrcode

• Normally generate QR code across version 1 to version 40 *
• Automatically analyze QR version by source text *
• Applying image size with WithImageSize
• Applying padding for QR code with WithQuietZone
• Full customization of shapes:
  • Customize modules with WithModuleShape
    • Squares
    • Rounded,
    • Connected (no gaps between adjacent modules)
    • Lines
  • Customize finders (eyes) with WithFinderShape
  • "Connected" rounded modules with go gaps between
• Setting colors *: WithBgColor(Hex), WithFgColor(Hex)
  • Added support for hex colors with alpha channel (8 digits)
  • Gradient with customizable direction via WithGradient(dir, colors...).
    • Overrides foreground color
    • Colors will be automatically placed evenly on the gradient map
• Advanced logo placing:
  • WithLogo places image at center and rescales it to be 1/5 of qr code
  • WithSpaceAroundLogo add white space at the center so logo is not placed on top of modules
• Support Halftones

Install

go get -u github.com/quickqr/gqr

Using

Check other examples

package main

import (
  "github.com/quickqr/gqr"
  export "github.com/quickqr/gqr/export/image"
  "github.com/quickqr/gqr/export/image/shapes"
  "image"
  "image/png"
  "log"
  "os"
)

func main() {
  qr, e := gqr.NewWith(
    "https://github.com/quickqr/gqr",
    // These are defaults, can be omitted (as it is in other examples)
    gqr.WithErrorCorrectionLevel(gqr.ErrorCorrectionHighest),
    gqr.WithEncodingMode(gqr.EncModeAuto),
    // Uncomment to force QR code version 23.
    // Note: you might get an error if supplied length is more than capacity of a specified version
    // gqr.WithVersion(23)
  )

  if e != nil {
    log.Fatal(e)
  }

  logoFile, _ := os.Open("./gopher.png")
  logo, _, _ := image.Decode(logoFile)

  // Export QR code to image
  img := export.
          NewExporter(
            export.WithBgColorHex("#ffffff"),

            export.WithLogo(logo),
            export.WithSpaceAroundLogo(),

            export.WithFinderShape(shapes.RoundedFinderShape(0.3)),
            export.WithModuleShape(shapes.RoundedModuleShape(0.5, true)),

            // Apply gap between modules (note: this particular example will not use it because of connected modules)
            // You can see this working as expected in invert.go and  custom-shapes.go
            export.WithModuleGap(0.1),
            // Size of the outputted image in pixels
            export.WithImageSize(1024),

            export.WithLogoScale(0.8),  // default
            // Padding around QR code
            // Note: actual QR code size will be (image size - quiet zone * 2)
            export.WithQuietZone(60),

            // Gradient for foreground with direction from Top Right to Bottom Left
            export.WithGradient(export.GradientDirectionLTR,
              export.ParseFromHex("#336FE1"),
              export.ParseFromHex("#2799C9"),
              // You also can use any color.Color instance
            ),
          ).
    Export(*qr)

  // Save the image
  f, _ := os.OpenFile("../assets/main.png", os.O_CREATE|os.O_WRONLY, 0644)
  if err := png.Encode(f, img); err != nil {
    log.Fatal(err)
  }
}

Showcase

All of these pictures are generated by programs in examples: