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Creating a PNG image in golang

March 13, 2015, 2:23 am

The following very simple example creates a PNG image file in golang. It first creates a Image structure and then populates this with random data.

A file is then creating using os.Create, this is used as a io.Writer to which golang’s PNG encoder in image/png writes the encoded PNG data via the png.Encode function.

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package main
 
import (
    "image"
    "image/png"
    "image/color"
    "os"
    "math/rand"
)
 
 
func main() {
 
  myimage := image.NewRGBA(image.Rectangle{image.Point{0,0},image.Point{100,100}})
 
  // This loop just fills the image with random data
  for x := 0; x < 100; x++ {
    for y := 0; y < 100; y++ {
      c := color.RGBA{uint8(rand.Intn(255)),uint8(rand.Intn(255)),uint8(rand.Intn(255)),255}
      myimage.Set(x,y,c)
    }
  }
 
  myfile, _ := os.Create("test.png")
 
  png.Encode(myfile, myimage)
}
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One Comment

  1. Rafał Korkosz says:
    February 11, 2016 at 10:10 am

    you should `defer myfile.Close()`

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