Hi Apple Developers!
I’m using the DetectBarcodesRequest function to identify QR codes in some images and PDFs.
However, I’m facing an issue where the function doesn’t detect the barcode on certain documents and machines, while it works on others using the same document.
The only common factor I’ve noticed is that the machines that successfully identify the QR code of the “problematic” document are all heavy developer machines that have Xcode installed. Interestingly, this doesn’t seem to be related to processor type (Intel vs. Apple Silicon).
Could you please provide some guidance or leads on how to resolve this issue?
VisionKit
RSS for tagScan documents with the camera on iPhone and iPad devices using VisionKit.
Posts under VisionKit tag
29 Posts
Selecting any option will automatically load the page
Post
Replies
Boosts
Views
Activity
Hi,
I'm working with a very simple app that tries to read a coordinates card and past the data into diferent fields. The card's layout is COLUMNS from 1-10, ROWs from A-J and a two digit number for each cell. In my app, I have field for each of those cells (A1, A2...). I want that OCR to read that card and paste the info but I just cant. I have two problems. The camera won't close. It remains open until I press the button SAVE (this is not good because a user could take 3, 4, 5... pictures of the same card with, maybe, different results, and then? Which is the good one?). Then, after I press save, I can see the OCR kinda works ( the console prints all the date read) but the info is not pasted at all.
Any idea? I know is hard to know what's wrong but I've tried chatgpt and all it does... just doesn't work
This is the code from the scanview
import SwiftUI
import Vision
import VisionKit
struct ScanCardView: UIViewControllerRepresentable {
@Binding var scannedCoordinates: [String: String]
var useLettersForColumns: Bool
var numberOfColumns: Int
var numberOfRows: Int
@Environment(.presentationMode) var presentationMode
func makeUIViewController(context: Context) -> VNDocumentCameraViewController {
let scannerVC = VNDocumentCameraViewController()
scannerVC.delegate = context.coordinator
return scannerVC
}
func updateUIViewController(_ uiViewController: VNDocumentCameraViewController, context: Context) {}
func makeCoordinator() -> Coordinator {
return Coordinator(self)
}
class Coordinator: NSObject, VNDocumentCameraViewControllerDelegate {
let parent: ScanCardView
init(_ parent: ScanCardView) {
self.parent = parent
}
func documentCameraViewController(_ controller: VNDocumentCameraViewController, didFinishWith scan: VNDocumentCameraScan) {
print("Escaneo completado, procesando imagen...")
guard scan.pageCount > 0, let image = scan.imageOfPage(at: 0).cgImage else {
print("No se pudo obtener la imagen del escaneo.")
controller.dismiss(animated: true, completion: nil)
return
}
recognizeText(from: image)
DispatchQueue.main.async {
print("Finalizando proceso OCR y cerrando la cámara.")
controller.dismiss(animated: true, completion: nil)
}
}
func documentCameraViewControllerDidCancel(_ controller: VNDocumentCameraViewController) {
print("Escaneo cancelado por el usuario.")
controller.dismiss(animated: true, completion: nil)
}
func documentCameraViewController(_ controller: VNDocumentCameraViewController, didFailWithError error: Error) {
print("Error en el escaneo: \(error.localizedDescription)")
controller.dismiss(animated: true, completion: nil)
}
private func recognizeText(from image: CGImage) {
let request = VNRecognizeTextRequest { (request, error) in
guard let observations = request.results as? [VNRecognizedTextObservation], error == nil else {
print("Error en el reconocimiento de texto: \(String(describing: error?.localizedDescription))")
DispatchQueue.main.async {
self.parent.presentationMode.wrappedValue.dismiss()
}
return
}
let recognizedStrings = observations.compactMap { observation in
observation.topCandidates(1).first?.string
}
print("Texto reconocido: \(recognizedStrings)")
let filteredCoordinates = self.filterValidCoordinates(from: recognizedStrings)
DispatchQueue.main.async {
print("Coordenadas detectadas después de filtrar: \(filteredCoordinates)")
self.parent.scannedCoordinates = filteredCoordinates
}
}
request.recognitionLevel = .accurate
let handler = VNImageRequestHandler(cgImage: image, options: [:])
DispatchQueue.global(qos: .userInitiated).async {
do {
try handler.perform([request])
print("OCR completado y datos procesados.")
} catch {
print("Error al realizar la solicitud de OCR: \(error.localizedDescription)")
}
}
}
private func filterValidCoordinates(from strings: [String]) -> [String: String] {
var result: [String: String] = [:]
print("Texto antes de filtrar: \(strings)")
for string in strings {
let trimmedString = string.replacingOccurrences(of: " ", with: "")
if parent.useLettersForColumns {
let pattern = "^[A-J]\\d{1,2}$" // Letras de A-J seguidas de 1 o 2 dígitos
if trimmedString.range(of: pattern, options: .regularExpression) != nil {
print("Coordenada válida detectada (letras): \(trimmedString)")
result[trimmedString] = "Valor" // Asignación de prueba
}
} else {
let pattern = "^[1-9]\\d{0,1}$" // Solo números, de 1 a 99
if trimmedString.range(of: pattern, options: .regularExpression) != nil {
print("Coordenada válida detectada (números): \(trimmedString)")
result[trimmedString] = "Valor"
}
}
}
print("Coordenadas finales después de filtrar: \(result)")
return result
}
}
}
I have an iPad app that I want to run on Apple Silicon macs.
Everything works fine except for VNDocumentCameraViewController. According to the docs this class is available on:
iOS 13.0+ iPadOS 13.0+ Mac Catalyst 13.1+ visionOS 1.0+
yet when I try using it I get Document camera is not available on my Mac Studio running macOS 15.2
Is this expected behaviour?
Thanks
Based on the iPhone 14 Max camera, implement model recognition and draw a rectangular box around the recognized object. The width and height are calculated using LiDAR and displayed in centimeters on the real-time updated image.
Hi, I’m learning MAUI and was trying to use VNDocumentCameraViewController provided by Vision Kit to scan documents and it is working fine but I realized that I was not able to customize some of the options provided by default like, disabling the auto scan option. Is there any way to disable the auto scan option or are there any other alternatives with the same founctionalities as VNDocumentCameraViewController that are more customizable?
He=I I have made this app with the Xcode 15.2 but the current stimulator is not able to open it properly with the error showing
Thanks
zipzy Games
Hi
I'm having a problem with DataScannerViewController, I'm using the volume barcode scanning feature in my app, prior to that I was using an AVCaptureDevice with the UltraWideAngle set. After discovering DataScannerViewController, we planned to replace the previous obsolete code with DataScannerViewController, all together it was ok, when I want to set the ultra wide angle, I don't know how to start.
I tried to get the minZoomFactor and I realized that I get 0.0
I tried to set zoomFactor to 1.0 and I found that he is not valid
Note: func dataScannerDidZoom(_ dataScanner: DataScannerViewController), when I try to get the minZoomFactor, set the zoomFactor in this proxy method, I find that it is valid!
What should I do next, I want to use only DataScannerViewController and implement ultra wide angle
Thanks a lot.
Hi everyone,
I'm working on an iOS app that uses VisionKit and I'm exploring the .visualLookUp feature. Specifically, I want to extract the detailed information that Visual Look Up provides after identifying an object in an image (e.g., if the object is a flower, retrieve its name; if it’s a clothing tag, get the tag's content).
Hi all,
I am developing an app that scans barcodes using VisionKit, but I am facing some difficulties.
The accuracy level is not at where I hope it to be at. Changing the “qualityLevel” parameter from balanced to accurate made the barcode reading slightly better, but it is still misreading some cases. I previously implemented the same barcode scanning app with AVFoundation, and that had much better accuracy. I tested it out, and barcodes that were read correctly with AVFoundation were read incorrectly with VisionKit . Is there anyway to improve the accuracy of the barcode reading in VisionKit? Or is this something that is built in and the developer cannot change? Either way, any ideas on how to improve reading accuracy would help.
Thanks in advance!