How to detect Bar Code from Image in Swift?

Question

I am trying to detect bar code from user selected image. I am able to detect QR code from the image but can not find anything related to bar code scanning from Image. The code I am using to detect QR code from image is like below:

func detectQRCode(_ image: UIImage?) -> [CIFeature]? {
        if let image = image, let ciImage = CIImage.init(image: image){
            var options: [String: Any]
            let context = CIContext()
            options = [CIDetectorAccuracy: CIDetectorAccuracyHigh]
            let qrDetector = CIDetector(ofType: CIDetectorTypeQRCode, context: context, options: options)
            if ciImage.properties.keys.contains((kCGImagePropertyOrientation as String)){
                options = [CIDetectorImageOrientation: ciImage.properties[(kCGImagePropertyOrientation as String)] ?? 1]
            }else {
                options = [CIDetectorImageOrientation: 1]
            }
            let features = qrDetector?.features(in: ciImage, options: options)
            return features

        }
        return nil
    }

When I go into the documentation of the CIDetectorTypeQRCode it says

/* Specifies a detector type for barcode detection. */
@available(iOS 8.0, *)
public let CIDetectorTypeQRCode: String

Though this is QR code Type documentation says it can detect barcode also. Fine. But when I use the same function to decode barcode it returns me empty array of features. Even if it returns me some features how will I be able to convert it to the bar code alternative of CIQRCodeFeature ? I do not see any bar code alternative in the documentation of CIQRCodeFeature. I know with ZBar SDK you can do this, but I am trying not to use any third party library here, or is it mandatory to use this in this regard??.

Please help, Thanks a lot.

Seems like `CIDetectorTypeQRCode` will only detect QR codes. The only supported types can be found in documentation https://developer.apple.com/documentation/coreimage/cidetector. If you don't want to rely on third party libraries, you will need to write a `CIDetector` yourself but I can't say how complex that attempt would be. — jms, Aug 18 '19 at 05:21
So third party is the only solution I guess. Okay. I will use MLKit from Firebase then. Thanks — Anuran Barman, Aug 18 '19 at 05:24
Do a [search on `VNDetectBarcodesRequest`](https://stackoverflow.com/search?q=VNDetectBarcodesRequest). — rmaddy, Aug 18 '19 at 05:48
@manishsharma93 That works for live video from the camera, not for a static image. — rmaddy, Aug 18 '19 at 13:32
I can't say how right I am @AnuranBarman, but you can see that the basic `CIRectangleFeature` is supported. You will have to write your own wrapper around it to detect Barcode. Seems like a pretty interesting exercise ^^ — jms, Aug 18 '19 at 16:50

Priya Talreja · Answer 1 · 2019-08-18T09:38:41.193

You can use Vision Framework

Barcode detection request code

var vnBarCodeDetectionRequest : VNDetectBarcodesRequest{
        let request = VNDetectBarcodesRequest { (request,error) in
            if let error = error as NSError? {
                print("Error in detecting - \(error)")
                return
            }
            else {
                guard let observations = request.results as? [VNDetectedObjectObservation]
                    else {
                        return
                }
                print("Observations are \(observations)")
            }
        }
        return request
    }

Function in which you need to pass the image.

func createVisionRequest(image: UIImage)
    {
        guard let cgImage = image.cgImage else {
            return
        }
        let requestHandler = VNImageRequestHandler(cgImage: cgImage, orientation: image.cgImageOrientation, options: [:])
        let vnRequests = [vnBarCodeDetectionRequest]
        DispatchQueue.global(qos: .background).async {
            do{
                try requestHandler.perform(vnRequests)
            }catch let error as NSError {
                print("Error in performing Image request: \(error)")
            }
        } 
    }

Reference Link

Interesting. Thanks for the link. extra knowledge. I have already made this work by Firebase MLKit. Thanks for the answer though — Anuran Barman, Aug 19 '19 at 07:09

How to detect Bar Code from Image in Swift?

1 Answers1