CIDetector 未检测到二维码

Question

我正在尝试使用 CIDetector 从 UIImage 中检测 QRCode，以便从中提取 messageString。

我有一个函数，它基本上接收 UIImage 作为输入并返回解码后的 messageString。

我传递给此函数的 UIImage 是使用 PHAsset、PHAssetCollection、PHImageRequestOptions 等从用户库中提取的。请求是同步发出的，我得到的所有图像质量都很好（我试图展示图像在 UIImageView 中只是为了确保图像可读）。

在这里您可以看到请求图像的代码的 sn-p：

let _: PHImageRequestID = PHImageManager.defaultManager().requestImageForAsset(asset as! PHAsset, targetSize: size, contentMode: PHImageContentMode.AspectFit, options: options, resultHandler: { (image: UIImage?, info:[NSObject : AnyObject]?) -> Void in
                    images.append(image!)
                })

获取图像后，我想检测二维码，我正在使用以下代码：

func scanImage(image: CIImage) -> String {

    let detector = CIDetector(ofType: CIDetectorTypeQRCode, context: nil, options: [CIDetectorAccuracy:CIDetectorAccuracyHigh])
    var image = CIImage(image: uiimage)

    var decode = ""
    let features = detector.featuresInImage(image!)
    for feature in features as! [CIQRCodeFeature] {
        decode = feature.messageString
    }
    return decode
}

我发现了这个 (Core Image Detector(CIDetector) is not detecting QRCodes) 和其他类似的问题，但它们似乎都不起作用。

这是我遵循的教程https://www.shinobicontrols.com/blog/ios8-day-by-day-day-13-coreimage-detectors

我是不是做错了什么？

提前致谢

Answer 1

问题是您在函数中传递 CIImage

func scanImage(image: CIImage)

然后在

中添加另一个带有未定义图像的图像变量

var image = CIImage(image: uiimage)

去掉这行应该没问题 我正在为自己写一个二维码，如果你有兴趣，可以看看。

// open photo library 
func loadGallery() {
    let imagePicker = UIImagePickerController()
    imagePicker.delegate = self
    imagePicker.sourceType = .PhotoLibrary
    self.presentViewController(imagePicker,
        animated: true,
        completion: nil)
}

// read QRCode from selecting image
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
    let qrImg:UIImage = info[UIImagePickerControllerOriginalImage] as! UIImage

    if #available(iOS 8.0, *) {
        let detector:CIDetector = CIDetector(ofType: CIDetectorTypeQRCode, context:nil, options:[CIDetectorAccuracy: CIDetectorAccuracyHigh])
        let ciimg: CIImage = CIImage(image: qrImg)!
        let features = detector.featuresInImage(ciimg)

        for feature in features as! [CIQRCodeFeature] {
            print(feature.messageString)
        }


    } else {
        // Fallback on earlier versions
    }

    dismissViewControllerAnimated(true, completion: nil)
}

更新到 Swift 3 xcode 8.1

// read QRCode from selecting image
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {


    let qrImg:UIImage = info[UIImagePickerControllerOriginalImage] as! UIImage

    if #available(iOS 8.0, *) {
        let detector:CIDetector = CIDetector(ofType: CIDetectorTypeQRCode, context:nil, options:[CIDetectorAccuracy: CIDetectorAccuracyHigh])!
        let ciimg: CIImage = CIImage(image: qrImg)!
        let features = detector.features(in: ciimg)

        for feature in features as! [CIQRCodeFeature] {
            print(feature.messageString!)
        }


    } else {
        // Fallback on earlier versions
    }
    dismiss(animated: true, completion: nil)
}

希望对你有帮助