提高阅读QR和PDF417代码与AVFoundation swift

Question

我正在尝试阅读PDF-417和QR码，我的代码工作，但当光线较少或图像模糊时不起作用。所以我正在寻找有关如何提高阅读代码的信息。

我试着改变相机上的设置:AVCaptureSession增加了分辨率设置，AVCaptureDevice增加了videoZoomFactor，但显然我做得不对。

我希望你能帮助我。

import UIKit  
import AVFoundation  
class ViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate { 

let session         : AVCaptureSession = AVCaptureSession()  
var previewLayer    : AVCaptureVideoPreviewLayer!  
var highlightView   : UIView = UIView()  
override func viewDidLoad() {  
    super.viewDidLoad()  
    /  
    self.highlightView.autoresizingMask =   UIViewAutoresizing.FlexibleTopMargin |  
        UIViewAutoresizing.FlexibleBottomMargin |  
        UIViewAutoresizing.FlexibleLeftMargin |  
        UIViewAutoresizing.FlexibleRightMargin  
    /  
    self.highlightView.layer.borderColor = UIColor.greenColor().CGColor  
    self.highlightView.layer.borderWidth = 3  
    /  
    self.view.addSubview(self.highlightView)  
    /  
    let device = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)  
    /  
    /  
    var error : NSError? = nil  

    let input : AVCaptureDeviceInput? = AVCaptureDeviceInput.deviceInputWithDevice(device, error: &error) as? AVCaptureDeviceInput  
    /  
    if input != nil {  
        session.addInput(input)  
    }  
    else {  
        /  
        println(error)  
    }  
    let output = AVCaptureMetadataOutput()  
    output.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())  
    session.addOutput(output)  
    output.metadataObjectTypes = output.availableMetadataObjectTypes  

    previewLayer = AVCaptureVideoPreviewLayer.layerWithSession(session) as! AVCaptureVideoPreviewLayer  
    previewLayer.frame = self.view.bounds  
    previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill  
    self.view.layer.addSublayer(previewLayer)  
    /  
    session.startRunning()  
}  
/  
func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]!, fromConnection connection: AVCaptureConnection!) {  
    var highlightViewRect = CGRectZero  
    var barCodeObject : AVMetadataMachineReadableCodeObject!  
    var detectionString : String!  
    let barCodeTypes = [  
        AVMetadataObjectTypePDF417Code,  
        AVMetadataObjectTypeQRCode  
    ]  
    /  
    for metadata in metadataObjects {  
        for barcodeType in barCodeTypes {  
            if metadata.type == barcodeType  
            {  
                barCodeObject = self.previewLayer.transformedMetadataObjectForMetadataObject(metadata as! AVMetadataMachineReadableCodeObject) as! AVMetadataMachineReadableCodeObject  
                highlightViewRect = barCodeObject.bounds  
                detectionString = (metadata as! AVMetadataMachineReadableCodeObject).stringValue  
                self.session.stopRunning()  
                self.alert(detectionString)  
                break  
            }  
        }  
    }  
    println(detectionString)  
    self.highlightView.frame = highlightViewRect  
    self.view.bringSubviewToFront(self.highlightView)  
}  
func alert(Code: String)  
{  
    let actionSheet:UIAlertController = UIAlertController(title: "Barcode", message: "(Code)", preferredStyle: UIAlertControllerStyle.Alert)  
    let firstAlertAction:UIAlertAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler:  
    {  
        (alertAction:UIAlertAction!) in  
            self.session.startRunning()  
    })  
    actionSheet.addAction(firstAlertAction)  
    self.presentViewController(actionSheet, animated: true, completion: nil)  
}  
} 

Answer 1

我挣扎于qr码的不一致读取，对我来说有效的是使qr码尽可能成比例。(如果从另一个iphone/ipad屏幕上阅读)如果这对你没有帮助，http://www.appcoda.com/qr-code-reader-swift/<——帮了我欢呼声