Image Processing with Go

The usual story of aphid meets programming language is to see what it's like at image processing.

file.go from the Go Tutorial

package main

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

var errn = 0
func abort(e os.Error) {
        errn++
        if e != nil {
                fmt.Printf("ERR %s\n", e)
                os.Exit(errn)
        }
}

func main() {
        fd, err := file.Open("in.png", 0, 0)
        abort(err)
        var img image.Image
        img, err = png.Decode(fd)
        fd.Close()
        abort(err)
        w, h := img.Width(), img.Height()
        opng := image.NewNRGBA(w, h)
        var c image.Color
        for y := 0; y < h; y++ {
        for x := 0; x < w; x++ {
                c = img.At(x, y)
                opng.Set(x, y, c)
        }
        }

        fd, err = file.Open("create.png", os.O_RDWR | os.O_CREATE, 0644)
        abort(err)
        err = png.Encode(fd, opng)
        abort(err)
        fd.Close()
}

% cd /dev/shm; cp $home/1920x1440.png in.png; time /tmp/8.out
real 0m9.810s
user 0m12.425s
sys 0m0.072s


around 1s per 2000 pixels