Golang : Generate EAN barcode

Short tutorial on how to use https://github.com/boombuler/barcode package to generate EAN(European Article Number, but now known as International Article Number) barcode. Code adapted from previous codabar tutorial.

Here you go :

 package main

 import (
 "fmt"
 "github.com/boombuler/barcode"
 "github.com/boombuler/barcode/ean"
 "github.com/disintegration/imaging"
 "github.com/llgcode/draw2d"
 "image"
 "image/color"
 "image/draw"
 "os"
 )

 func main() {

 // 13 digits
 code := "5901234123457"

 fmt.Println("Generating Datamatrix barcode for : ", code)

 // see https://godoc.org/github.com/boombuler/barcode/ean
 bcode, err := ean.Encode(code)

 // uncomment if checksum missmatch
 //fmt.Println(err)

 if err != nil {
 fmt.Printf("String %s cannot be encoded\n", code)
 os.Exit(1)
 }

 // scale to 100x100
 bcode, err = barcode.Scale(bcode, 100, 100)

 if err != nil {
 fmt.Println("EAN scaling error : ", err)
 os.Exit(1)
 }

 // now we want to append the code at the bottom
 // of the EAN

 // Create an new image with text data
 // From https://github.com/llgcode/draw2d.samples/tree/master/helloworld
 // Set the global folder for searching fonts
 draw2d.SetFontFolder(".")

 // Initialize the graphic context on an RGBA image
 img := image.NewRGBA(image.Rect(0, 0, 250, 50))

 // set background to white
 white := color.RGBA{255, 255, 255, 255}
 draw.Draw(img, img.Bounds(), &image.Uniform{white}, image.ZP, draw.Src)

 gc := draw2d.NewGraphicContext(img)

 gc.FillStroke()

 // Set the font Montereymbi.ttf
 gc.SetFontData(draw2d.FontData{"Monterey", draw2d.FontFamilyMono, draw2d.FontStyleBold | draw2d.FontStyleItalic})
 // Set the fill text color to black
 gc.SetFillColor(image.Black)

 gc.SetFontSize(14)
 gc.FillStringAt(code, 50, 20)

 // create a new blank image with white background
 newImg := imaging.New(300, 200, color.NRGBA{255, 255, 255, 255})

 //paste the codabar to new blank image
 newImg = imaging.Paste(newImg, bcode, image.Pt(100, 30))

 //paste the text to the new blank image
 newImg = imaging.Paste(newImg, img, image.Pt(50, 150))

 err = draw2d.SaveToPngFile("./ean.png", newImg)

 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }

 // everything ok
 fmt.Println("EAN barcode generated and saved to ean.png")

 }

Sample output :

References :

https://godoc.org/github.com/boombuler/barcode/ean