GrayChannelValue operator()(const RedChannel& red, const GreenChannel& green, const BlueChannel& blue) const {
return channel_convert<GrayChannelValue>( bits32f(
channel_convert<bits32f>(red )*0.30f +
channel_convert<bits32f>(green)*0.59f +
channel_convert<bits32f>(blue )*0.11f) );
}
bits32f operator()(bits16h h) const { return bits32f(float(half(h))); }
