go get -u github.com/codenoid/go-screenshot

package main

import (
	"image/jpeg"
	"os"

	screenshot "github.com/codenoid/go-screenshot"
)

func main() {
	// start xgb session, you can reuse this for anything else
	xgbconn, err := screenshot.NewSession()
	if err != nil {
		return
	}
	defer xgbconn.Close()

	// call screenshot method
	ss := screenshot.Start{
		XgbConn: xgbconn,
	}

	// capture current screen frame
	img, err := ss.CaptureScreen()

	f, err := os.Create("screenshot.jpg")
	if err != nil {
		panic(err)
	}
	defer f.Close()

	jpeg.Encode(f, img, nil)
}