Microblink：成功读取一张图片答案

【问题标题】：Microblink: successfully reading an imageMicroblink：成功读取一张图片
【发布时间】：2021-03-16 13:33:03
【问题描述】：

我要求 Microblink 读卡器查看卡片的照片，而不是使用相机。我已经尝试过万事达卡的纵向和横向版本。这就是我声明主要变量的方式：

let blinkCardRecognizer = MBCBlinkCardRecognizer()
var recognizerList = [MBCRecognizer]()

lazy var recognizerCollection: MBCRecognizerCollection = {
    blinkCardRecognizer.extractCvv = false
    blinkCardRecognizer.extractIban = false
    blinkCardRecognizer.extractExpiryDate = false

    recognizerList.append(blinkCardRecognizer)
    return MBCRecognizerCollection(recognizers: recognizerList)
}()
lazy var recognizerRunner: MBCRecognizerRunner = {
    MBCRecognizerRunner(recognizerCollection: recognizerCollection)
}()

我已经声明了这两个代表：

MBCBlinkCardOverlayViewControllerDelegate, MBCScanningRecognizerRunnerDelegate

在我得到我的 UIImage 之后，我调用了这个函数：

func prepareToReadImage(_ theImage: UIImage?) {
    recognizerRunner.scanningRecognizerRunnerDelegate = self
    
    var image: MBCImage? = nil
    if let anImage = theImage {
        image = MBCImage(uiImage: anImage)
    }
    image?.cameraFrame = true
    image?.orientation = MBCProcessingOrientation.down
    let _serialQueue = DispatchQueue(label: "com.microblink.DirectAPI-sample-swift")
    _serialQueue.async(execute: {() -> Void in
        self.recognizerRunner.processImage(image!)
    })
}

这是我的委托回调。每次，我都会得到.empty的状态：

func recognizerRunner(_ recognizerRunner: MBCRecognizerRunner, didFinishScanningWith state: MBCRecognizerResultState) {
    if state == .valid { // values: .empty, .uncertain, .valid, .stageValid
        let result = blinkCardRecognizer.result
        
        DispatchQueue.main.async(execute: {() -> Void in
            print (result.owner)
            print (result.cardNumber)
            print (result.cardNumberPrefix)
        })
    }
}

我没有收到.valid 回复的任何原因？此外，这看起来像是提取卡详细信息的正确方法吗，一次（如果以及何时）我这样做？谢谢！

【问题讨论】：

标签： ios microblink

【解决方案1】：

这个问题是否与here 问题有关？

如果是这样，我还可以提出以下建议：您可以添加一个调用图像选择器的函数（我使用设备相机作为源类型）：

private func openImagePicker() {
        let imagePicker = UIImagePickerController()
        imagePicker.sourceType = .camera
        imagePicker.cameraDevice = .rear

        addOverlayLabel(toImagePicker: imagePicker)
        
        // Displays a control that allows the user to choose only photos
        imagePicker.mediaTypes = [kUTTypeImage as String]
        
        // Hides the controls for moving & scaling pictures, or for trimming movies.
        imagePicker.allowsEditing = false
        
        // Shows default camera control overlay over camera preview.
        imagePicker.showsCameraControls = true
        
        // set delegate
        imagePicker.delegate = self
        present(imagePicker, animated: true) {() -> Void in }
        imagePickerController = imagePicker
    }

在func recognizerRunner中可以放置状态无效时调用的func，像这样：

extension ViewController: MBCScanningRecognizerRunnerDelegate {

func recognizerRunner(_ recognizerRunner: MBCRecognizerRunner, didFinishScanningWith state: MBCRecognizerResultState) {
    DispatchQueue.main.async(execute: {() -> Void in
        if state != .valid {
            self.openImagePicker()
            return
        }
        
        print(state.rawValue)
        let result = self.blinkCardRecognizer.result

        print("Owner: \(result.owner)")
        print("Card number: \(result.cardNumber)")
        print("Card number prefix: \(result.cardNumberPrefix)")
        
    })
  }
}

如果状态无效，这将使您有机会重新拍摄图像。

还要问一下，你把prepareToReadImage放在哪里？

你需要把它放在func imagePickerController，像这样：

extension ViewController: UIImagePickerControllerDelegate {

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    let mediaType = info[UIImagePickerController.InfoKey.mediaType] as? String
    
    if CFStringCompare(mediaType as CFString?, kUTTypeImage, CFStringCompareFlags(rawValue: 9)) == .compareEqualTo {
        let originalImage = info[UIImagePickerController.InfoKey.originalImage] as? UIImage
        prepareToReadImage(originalImage)
    }
    
    picker.dismiss(animated: true, completion: nil)
}

func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
    serialQueue.async {
        self.recognizerRunner?.resetState()
    }

    dismiss(animated: true, completion: nil)

  }
}

最后，请确保在开始扫描过程之前放置识别器的设置。

我添加了func setupRecognizerRunner，在这里我定义了你在代码块中所做的一切：

    private func setupRecognizerRunner() {

    blinkCardRecognizer = MBCBlinkCardRecognizer()
    var recognizers = [MBCRecognizer]()
    
    blinkCardRecognizer.extractCvv = false
    blinkCardRecognizer.extractIban = false
    blinkCardRecognizer.extractExpiryDate = false
    
    recognizers.append(blinkCardRecognizer)
    let recognizerCollection = MBCRecognizerCollection(recognizers: recognizers)
    recognizerRunner = MBCRecognizerRunner(recognizerCollection: recognizerCollection)
    
    recognizerRunner?.scanningRecognizerRunnerDelegate = self
}

我已经把它放在了viewDidLoad()，在加载了许可密钥方法之后。

【讨论】：

【解决方案2】：

删除以下行让我得到.valid 响应：

image?.cameraFrame = true

【讨论】：