added byte offset from new spec

esi.go

@@ -50,6 +50,8 @@ var (
 	errNotESI       = errors.New("esi: not an esi")
 )
 
+var emptyBytes = 7
+
 func init() {
 	image.RegisterFormat("esi", "esi1", Decode, DecodeConfig)
 }
@@ -72,7 +74,7 @@ func Decode(r io.Reader) (o image.Image, err error) {
 
 	img := image.NewRGBA(bounds)
 
-	buf.Next(8)
+	buf.Next(8 + 7)
 
 	for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
 		for x := bounds.Min.X; x < bounds.Max.X; x++ {
@@ -181,7 +183,7 @@ func Encode(w io.Writer, img image.Image) error {
 		configByte |= 32
 	}
 
-	_, err = w.Write([]byte{configByte, 0})
+	_, err = w.Write([]byte{configByte, 0, 0, 0, 0, 0, 0, 0, 0})
 	if err != nil {
 		return err
 	}