package main

import (
	"image"
	"image/gif"
	_ "image/jpeg"
	_ "image/png"
	"os"
)

func main() {
	r, w := os.Stdin, os.Stdout
	img, format, err := image.Decode(r)
	println("registered format:", format)
	if err != nil {
		panic(err)
	}
	err = gif.Encode(w, img, &gif.Options{256, nil, nil})
	if err != nil {
		panic(err)
	}
}