func avgColor(neighbours ...image.RGBAColor) (image.Color, os.Error) {
weight := len(neighbours)
var R, G, B, A int
var avg image.RGBAColor
if weight != 0 {
for _, c := range neighbours {
R += int(c.R)
G += int(c.G)
B += int(c.B)
A += int(c.A)
}
avg.R = uint8(R / weight)
avg.G = uint8(G / weight)
avg.B = uint8(B / weight)
avg.A = uint8(A / weight)
return avg, nil
}
return avg, os.NewError("zero arguments")
}
