subsampleRatio = image.YCbCrSubsampleRatio444
	case 0x12:
		subsampleRatio = image.YCbCrSubsampleRatio440
	case 0x21:
		subsampleRatio = image.YCbCrSubsampleRatio422
	case 0x22:
		subsampleRatio = image.YCbCrSubsampleRatio420
	case 0x41:
		subsampleRatio = image.YCbCrSubsampleRatio411
	case 0x42:
		subsampleRatio = image.YCbCrSubsampleRatio410
	default:
		panic("unreachable")
	}