bool needs_srgb_primaries() const override { return false; }
unsigned num_inputs() const override { return 2; }
bool needs_srgb_primaries() const override { return false; }
unsigned num_inputs() const override { return 2; }
// Actually, if _either_ image has blank alpha, our output will have
// blank alpha, too (this only tells the framework that having _both_
// Actually, if _either_ image has blank alpha, our output will have
// blank alpha, too (this only tells the framework that having _both_