如何在ios，swift中从字符串中获取高质量的条码图像

import AVFoundation

let captureSession = AVCaptureSession()

guard let captureDevice = AVCaptureDevice.default(for: .video) else {
    // 处理设备不可用的情况
    return
}

do {
    let input = try AVCaptureDeviceInput(device: captureDevice)
    captureSession.addInput(input)
} catch {
    // 处理输入设备错误的情况
    return
}

let metadataOutput = AVCaptureMetadataOutput()
captureSession.addOutput(metadataOutput)
metadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
metadataOutput.metadataObjectTypes = [.ean13, .qr] // 设置要识别的条码类型

extension YourViewController: AVCaptureMetadataOutputObjectsDelegate {
    func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
        guard let metadataObject = metadataObjects.first as? AVMetadataMachineReadableCodeObject,
              let barcodeImage = captureSession.output(for: metadataOutput) as? AVCaptureVideoDataOutput else {
            // 处理未能获取到条码图像的情况
            return
        }
        
        // 在这里可以使用barcodeImage来处理条码图像
    }
}

captureSession.startRunning()