go-qrcode #

QR code (abbreviated from Quick Response Code) is the trademark for a type of matrix barcode (or two-dimensional barcode) first designed in 1994 for the automotive industry in Japan. A barcode is a machine-readable optical label that contains information about the item to which it is attached. A QR code uses four standardized encoding modes (numeric, alphanumeric, byte/binary, and kanji) to store data efficiently; extensions may also be used

Features

• [x] Normally generate QR code across version 1 to version 40.
• [x] Automatically analyze QR version by source text.
• [x] Specifying cell shape allowably with WithCustomShape, WithCircleShape (default is rectangle)
• [x] Specifying output file's format with WithBuiltinImageEncoder, WithCustomImageEncoder (default is JPEG)
• [x] Not only shape of cell, but also color of QR Code background and foreground color.
• [x] WithLogoImage, WithLogoImageFilePNG, WithLogoImageFileJPEG help you add an icon at the central of QR Code.
• [x] WithBorderWidth allows to specify any width of 4 sides around the qrcode.
• [x] WebAssembly support, check out the Example and README for more detail.
• [x] support Halftone QR Codes, check out the Example.

Install

go get -u github.com/yeqown/go-qrcode/v2

Quick Start

link to CODE

package main

import ( 	"github.com/yeqown/go-qrcode/v2" 	"github.com/yeqown/go-qrcode/writer/standard" )
func main() { 	qrc, err := qrcode.New("https://github.com/yeqown/go-qrcode") 	if err != nil { 		fmt.Printf("could not generate QRCode: %v", err) 		return 	} 	 	w, err := standard.New("../assets/repo-qrcode.jpeg") 	if err != nil { 		fmt.Printf("standard.New failed: %v", err) 		return 	} 	 	// save file 	if err = qrc.Save(w); err != nil { 		fmt.Printf("could not save image: %v", err) 	} }

Options

const (
	// EncModeNone mode ...
	EncModeNone encMode = 1 << iota
	// EncModeNumeric mode ...
	EncModeNumeric
	// EncModeAlphanumeric mode ...
	EncModeAlphanumeric
	// EncModeByte mode ...
	EncModeByte
	// EncModeKanji mode ...
	EncModeKanji
)
// WithEncodingMode sets the encoding mode. func WithEncodingMode(mode encMode) EncodeOption {}
const ( 	// ErrorCorrectionLow :Level L: 7% error recovery. 	ErrorCorrectionLow ecLevel = iota + 1 	 	// ErrorCorrectionMedium :Level M: 15% error recovery. Good default choice. 	ErrorCorrectionMedium 	 	// ErrorCorrectionQuart :Level Q: 25% error recovery. 	ErrorCorrectionQuart 	 	// ErrorCorrectionHighest :Level H: 30% error recovery. 	ErrorCorrectionHighest )
// WithErrorCorrectionLevel sets the error correction level. func WithErrorCorrectionLevel(ecLevel ecLevel) EncodeOption {}

Samples

These samples are generated with standard writer, check out Example for more details.

| A | B | C | D | |--------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------| |
bg-fg color |
transparent |
border padding |
circle shape | |
fg gradient |
using halftone |
set logo image |
block width | |
custom shape | | | |

Built-in Writers

• Standard Writer, prints QRCode into file and stream
• Terminal Writer, prints QRCode into terminal
• File Writer, prints QRCode into files
• Compressed Writer, It's generated on a very small scale

Migrating from v1

go-qrcode.v2 is a major upgrade from v1, and it is not backward compatible. v2 redesigned the API, and it is more flexible and powerful. Features are split into different modules (according to functionality).

• github.com/yeqown/go-qrcode/v2 core
• github.com/yeqown/go-qrcode/writer/standard writer/imageFile
• github.com/yeqown/go-qrcode/writer/terminal writer/terminal

Links

• QRCode Tourist
• QRCode Wiki
• 二维码详解 (QRCode analysis in CN-zh)
• 数据编码 (How to encode data payload in QRCode in CN-zh)