更新：我制作了一个完全开源的项目，可以帮助您完成所需的工作。看看吧：https://github.com/ethanwa/credit-card-scanner-and-validator
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除了添加一些预设值来专门查找之外，您无法做很多事情来提高准确性，这对于 CC 编号没有意义，因此我什至不会费心展示该代码。您需要依靠 Apple 来改进他们的文本识别模型，因为 iOS 会迭代以使其真正得到改进。
与此同时，我建议您可以做以下两件事：
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对您认为自己收到的信用卡号进行验证。例如，Visa 以 4 开头，MasterCard 以 5 开头，Discover 以 6 开头，Amex 以 3 开头，等等。它们有特定的长度等等。见这里：https://www.freeformatter.com/credit-card-number-generator-validator.html
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在相机源上一遍又一遍地迭代，直到你得到一个可以验证的数字。我不确定您当前是否只是在为卡拍照并处理该图像（听起来像您正在做的那样），但您应该每秒处理许多图像，直到获得有效的 CC。这很可能是 Apple 在您的手机上通过 Apple Pay 添加卡或使用银行应用以数字方式存入支票（查找有效路由和帐号）时的做法。
这是我的意思的一个例子......
我编写的这段代码可以在任何给定文本中挑选和验证 ISBN 编号（基本上是编目书籍的 10 和 13 位数字，其中有一个校验位用于验证），并且会一直查找直到找到所有数字，然后验证。它工作得非常好，而且速度非常快。看看这个 Swift 5.3 代码：
import UIKit
import Vision
import Photos
import AVFoundation
class ViewController: UIViewController, AVCaptureVideoDataOutputSampleBufferDelegate {
var recognizedText = ""
var finalText = ""
var image: UIImage?
var processing = false
@IBOutlet weak var nameLabel: UILabel!
@IBOutlet weak var setLabel: UILabel!
@IBOutlet weak var numberLabel: UILabel!
lazy var textDetectionRequest: VNRecognizeTextRequest = {
let request = VNRecognizeTextRequest(completionHandler: self.handleDetectedText)
request.recognitionLevel = .accurate
request.usesLanguageCorrection = false
return request
}()
private let videoOutput = AVCaptureVideoDataOutput()
private let captureSession = AVCaptureSession()
private lazy var previewLayer: AVCaptureVideoPreviewLayer = {
let preview = AVCaptureVideoPreviewLayer(session: self.captureSession)
preview.videoGravity = .resizeAspect
return preview
}()
// MARK: AV
override func viewDidLoad() {
super.viewDidLoad()
self.addCameraInput()
self.addVideoOutput()
}
private func addCameraInput() {
let device = AVCaptureDevice.default(for: .video)!
let cameraInput = try! AVCaptureDeviceInput(device: device)
self.captureSession.addInput(cameraInput)
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
self.previewLayer.frame = self.view.bounds
}
private func addVideoOutput() {
self.videoOutput.videoSettings = [(kCVPixelBufferPixelFormatTypeKey as NSString) : NSNumber(value: kCVPixelFormatType_32BGRA)] as [String : Any]
self.videoOutput.setSampleBufferDelegate(self, queue: DispatchQueue(label: "my.image.handling.queue"))
self.captureSession.addOutput(self.videoOutput)
}
func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection)
{
if !processing
{
guard let frame = CMSampleBufferGetImageBuffer(sampleBuffer) else {
debugPrint("unable to get image from sample buffer")
return
}
print("did receive image frame")
// process image here
self.processing = true
let ciimage : CIImage = CIImage(cvPixelBuffer: frame)
let theimage : UIImage = self.convert(cmage: ciimage)
self.image = theimage
processImage()
}
}
// Convert CIImage to CGImage
func convert(cmage:CIImage) -> UIImage
{
let context:CIContext = CIContext.init(options: nil)
let cgImage:CGImage = context.createCGImage(cmage, from: cmage.extent)!
let image:UIImage = UIImage.init(cgImage: cgImage)
return image
}
// AV
func processImage()
{
DispatchQueue.main.async {
self.nameLabel.text = ""
self.setLabel.text = ""
self.numberLabel.text = ""
}
guard let image = image, let cgImage = image.cgImage else { return }
let requests = [textDetectionRequest]
let imageRequestHandler = VNImageRequestHandler(cgImage: cgImage, orientation: .right, options: [:])
DispatchQueue.global(qos: .userInitiated).async {
do {
try imageRequestHandler.perform(requests)
} catch let error {
print("Error: \(error)")
}
}
}
fileprivate func handleDetectedText(request: VNRequest?, error: Error?)
{
self.finalText = ""
if let error = error {
print(error.localizedDescription)
self.processing = false
return
}
guard let results = request?.results, results.count > 0 else {
print("No text was found.")
self.processing = false
return
}
if let requestResults = request?.results as? [VNRecognizedTextObservation] {
self.recognizedText = ""
for observation in requestResults {
guard let candidiate = observation.topCandidates(1).first else { return }
self.recognizedText += candidiate.string
self.recognizedText += " "
}
var replaced = self.recognizedText.replacingOccurrences(of: "-", with: "")
replaced = String(replaced.filter { !"\n\t\r".contains($0) })
let replacedArr = replaced.components(separatedBy: " ")
for here in replacedArr
{
let final = here.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines)
if (final.count == 10 || final.count == 13) && final.containsISBNnums && Validate.isbn(final) // validate barcode
{
self.finalText += final
print(final)
self.captureSession.stopRunning()
DispatchQueue.main.async {
self.previewLayer.removeFromSuperlayer()
}
break
}
}
DispatchQueue.main.async {
self.numberLabel.text = self.finalText
}
}
self.processing = false
}
// MARK: Buttons
// This is a live camera view that will start a capture session
@IBAction func takePhoto(_ sender: Any) {
self.view.layer.addSublayer(self.previewLayer)
self.captureSession.startRunning()
}
@IBAction func choosePhoto(_ sender: Any) {
presentPhotoPicker(type: .photoLibrary)
}
fileprivate func presentPhotoPicker(type: UIImagePickerController.SourceType) {
let controller = UIImagePickerController()
controller.sourceType = type
controller.delegate = self
present(controller, animated: true, completion: nil)
}
}
extension ViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
dismiss(animated: true, completion: nil)
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
dismiss(animated: true, completion: nil)
image = info[.originalImage] as? UIImage
processImage()
}
}
extension String {
var containsISBNnums: Bool {
guard self.count > 0 else { return false }
let nums: Set<Character> = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "X"]
return Set(self).isSubset(of: nums)
}
}