Handler with VNImageRequestHandler

Firstly below model method, Create handler constant with VNImageRequestHandler(Option with ciImage).

let handler = VNImageRequestHandler(ciImage: image)

And then, implement DispatchQueue.global(qos: .userInteractive).async method that will work on the background as we did before while computing the confidence rate.

let handler = VNImageRequestHandler(ciImage: image)
DispatchQueue.global(qos: .userInteractive).async {

}

Create do-catch block and process request with handler.perform().

let handler = VNImageRequestHandler(ciImage: image)
DispatchQueue.global(qos: .userInteractive).async {
    do {
            try handler.perform([request])
    } catch {
            print("Err :(")
    }
}

it's done. The final state of recognizeImage function:

func recognizeImage(image: CIImage) {

        resultLabel.text = "I'm investigating..."

        if let model = try? VNCoreMLModel(for: GoogLeNetPlaces().model) {
            let request = VNCoreMLRequest(model: model, completionHandler: { (vnrequest, error) in
                if let results = vnrequest.results as? [VNClassificationObservation] {
                    let topResult = results.first
                    DispatchQueue.main.async {
                        let confidenceRate = (topResult?.confidence)! * 100
                        let rounded = Int (confidenceRate * 100) / 100
                        self.resultLabel.text = "\(rounded)% it's \(topResult?.identifier ?? "Anonymous")"
                    }
                }
            })
            let handler = VNImageRequestHandler(ciImage: image)
            DispatchQueue.global(qos: .userInteractive).async {
                do {
                    try handler.perform([request])
                } catch {
                    print("Err :(")
                }
            }
        }
    }