c0 := NYCbCrA{YCbCr{0xff, 0x80, 0x80}, uint8(i)}
		c1 := Alpha{uint8(i)}
		if err := eq(c0, c1); err != nil {
			t.Errorf("i=0x%02x:\n%v", i, err)
		}
	}
}

// TestNYCbCrAYCbCr tests that NYCbCrA colors are a superset of YCbCr colors.
func TestNYCbCrAYCbCr(t *testing.T) {
	for i := 0; i < 256; i++ {
		c0 := NYCbCrA{YCbCr{uint8(i), 0x40, 0xc0}, 0xff}
		c1 := YCbCr{uint8(i), 0x40, 0xc0}
		if err := eq(c0, c1); err != nil {