Golang image.NewGray function examples

package image

 func NewGray(r Rectangle) *Gray
  

NewGray returns a new Gray with the given bounds.

Golang image.NewGray function usage examples

Example 1:

 package main

 import (
 "fmt"
 "image"
 "image/png"
 "os"
 )

 func init() {
 // without this register .. At(), Bounds() functions will
 // caused memory pointer error!!
 image.RegisterFormat("png", "png", png.Decode, png.DecodeConfig)
 }

 func main() {
 imgfile, err := os.Open("./img.png")

 if err != nil {
 fmt.Println("img.png file not found!")
 os.Exit(1)
 }

 defer imgfile.Close()

 img, _, err := image.Decode(imgfile)

 bounds := img.Bounds()

 newgraycanvas := image.NewGray(bounds)

 rect := image.Rect(0, 0, 100, 100)

 subimg := newgraycanvas.SubImage(rect)

 fmt.Println(subimg.Bounds())
 fmt.Println(subimg.At(10, 10))
 }

Example 2:

 imgRect := image.Rect(0, 0, 200, 200)
 img := image.NewGray(imgRect)

References :

http://golang.org/pkg/image/#NewGray