visionによるQRコード認識

Visionフレームワークを使ってQRコードの認識を行ってみたのですが、QRCodeの中心座標は取得できるのですが端４点の座標を取得する方法がわかりません。
調べてみても出てこないのでvisionでは４点を追うことはできないのでしょうか？

swift
1import UIKit
2import AVFoundation
3import Vision
4
5class ViewController: UIViewController {
6 
7    @IBOutlet weak var previewImageView: UIImageView!
8    
9    override func viewDidLoad() {
10        super.viewDidLoad()
11        setupCamera()
12    }
13    override func viewDidAppear(_ animated: Bool) {
14        super.viewDidAppear(animated)
15    }
16 
17    override func viewDidDisappear(_ animated: Bool) {
18        super.viewDidDisappear(animated)
19        self.avCaptureSession.stopRunning()
20    }
21 
22    /// カメラのセットアップ
23    private func setupCamera() {
24        self.avCaptureSession.sessionPreset = .photo
25 
26        let device = AVCaptureDevice.default(.builtInUltraWideCamera,for: .video, position: .back)
27        let input = try! AVCaptureDeviceInput(device: device!)
28        self.avCaptureSession.addInput(input)
29 
30        let videoDataOutput = AVCaptureVideoDataOutput()
31        videoDataOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as String : Int(kCVPixelFormatType_32BGRA)]
32        videoDataOutput.alwaysDiscardsLateVideoFrames = true
33        videoDataOutput.setSampleBufferDelegate(self, queue: .global())
34        
35        self.avCaptureSession.addOutput(videoDataOutput)
36        self.avCaptureSession.startRunning()
37    }
38
39    /// コンテキストに矩形を描画
40    private func drawRect(_ rect: CGRect, context: CGContext) {
41        context.setLineWidth(4.0)
42        context.setStrokeColor(UIColor.green.cgColor)
43        context.stroke(rect)
44        
45    }
46    
47    /// QR識情報の配列取得 (非同期)
48    private func getQRObservations(pixelBuffer: CVPixelBuffer, completion: @escaping (([VNBarcodeObservation])->())) {
49        let request = VNDetectBarcodesRequest { (request, error) in
50            guard let results = request.results as? [VNBarcodeObservation] else {
51                completion([])
52                return
53            }
54            completion(results)
55        }
56        let handler = VNImageRequestHandler(cvPixelBuffer: pixelBuffer, options: [:])
57        try? handler.perform([request])
58        
59    }
60    
61    /// 正規化された矩形位置を指定領域に展開
62    private func getQRUnfoldRect(normalizedRect: CGRect, targetSize: CGSize) -> CGRect {
63        return CGRect(
64            x: normalizedRect.minX * targetSize.width,
65            y: normalizedRect.minY * targetSize.height,
66            width: normalizedRect.width * targetSize.width,
67            height: normalizedRect.height * targetSize.height
68            
69        )
70    }
71    /// QR出位置に矩形を描画した image を取得
72    private func getQRRectsImage(sampleBuffer :CMSampleBuffer, barcodeObservations: [VNBarcodeObservation]) -> UIImage? {
73        
74        guard let imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else {
75            return nil
76        }
77
78        CVPixelBufferLockBaseAddress(imageBuffer, CVPixelBufferLockFlags(rawValue: 0))
79
80        guard let pixelBufferBaseAddres = CVPixelBufferGetBaseAddressOfPlane(imageBuffer, 0) else {
81            CVPixelBufferUnlockBaseAddress(imageBuffer, CVPixelBufferLockFlags(rawValue: 0))
82            return nil
83        }
84        
85        let width = CVPixelBufferGetWidth(imageBuffer)
86        let height = CVPixelBufferGetHeight(imageBuffer)
87        let bitmapInfo = CGBitmapInfo(rawValue:
88            (CGBitmapInfo.byteOrder32Little.rawValue | CGImageAlphaInfo.premultipliedFirst.rawValue)
89        )
90
91        guard let newContext = CGContext(
92            data: pixelBufferBaseAddres,
93            width: width,
94            height: height,
95            bitsPerComponent: 8,
96            bytesPerRow: CVPixelBufferGetBytesPerRow(imageBuffer),
97            space: CGColorSpaceCreateDeviceRGB(),
98            bitmapInfo: bitmapInfo.rawValue
99            ) else
100        {
101            CVPixelBufferUnlockBaseAddress(imageBuffer, CVPixelBufferLockFlags(rawValue: 0))
102            return nil
103        }
104
105        let imageSize = CGSize(width: width, height: height)
106        let faseRects = barcodeObservations.compactMap {
107            getQRUnfoldRect(normalizedRect: $0.boundingBox, targetSize: imageSize)
108        }
109        faseRects.forEach{ self.drawRect($0, context: newContext) }
110        
111        CVPixelBufferUnlockBaseAddress(imageBuffer, CVPixelBufferLockFlags(rawValue: 0))
112
113        guard let imageRef = newContext.makeImage() else {
114            return nil
115        }
116        let image = UIImage(cgImage: imageRef, scale: 1.0, orientation: UIImage.Orientation.right)
117        
118        return image
119    }
120}
121
122extension ViewController : AVCaptureVideoDataOutputSampleBufferDelegate{
123    /// カメラからの映像取得デリゲート
124    func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
125        
126        guard let pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else {
127            return
128        }
129        
130        getQRObservations(pixelBuffer: pixelBuffer) { [weak self] barcodeObservations in
131            guard let self = self else { return }
132            let image = self.getQRRectsImage(sampleBuffer: sampleBuffer, barcodeObservations: barcodeObservations)
133            DispatchQueue.main.async { [weak self] in
134                self?.previewImageView.image = image
135            }
136        }
137       
138    }
139}

行動規範の内容に同意します

回答1件

ベストアンサー

VNBarcodeObservation クラスの親クラス VNRectangleObservation には、検出したオブジェクトの四隅の座標に対応するプロパティ bottomLeft , bottomRight , topLeft , topRight があるので、それらを使うのがよさそうです。

VNBarcodeObservation | Apple Developer Documentation
VNRectangleObservation | Apple Developer Documentation

下記リンク先のコードが参考になるかもしれません。
Vision.framework を使って QR コードを読む - ユニファ開発者ブログ

投稿2021/11/02 20:51