Scanning Live Video Streams with IronQR
You want to read QR codes in real time from a phone's camera, but IronQR has no built-in method for live video stream scanning. The workaround is to feed the reader individual frames from the camera, one at a time.
Solution
IronQR is focused on high-accuracy static QR code recognition. Real-time video decoding is the domain of computer vision frameworks like OpenCV or the platform-native camera SDKs. To get the effect of live scanning, capture frames yourself and decode each as a still image.
1. Access the device's camera feed
Open the camera through a platform-native API: Xamarin.Essentials, MAUI Camera, or the Android/iOS SDKs directly.
2. Grab frames continuously
Pull a frame on a short interval, for example every 100ms, and convert it into a bitmap.
3. Pass each frame to the reader
Wrap the captured bitmap in a QrImageInput and hand it to QrReader.Read().
// Load the asset into QrImageInput
QrImageInput imageInput = new QrImageInput(capturedBitmap);
// Create a QR Reader object
QrReader reader = new QrReader();
// Read the Input an get all embedded QR Codes
IEnumerable<QrResult> results = reader.Read(imageInput);' Load the asset into QrImageInput
Dim imageInput As New QrImageInput(capturedBitmap)
' Create a QR Reader object
Dim reader As New QrReader()
' Read the Input and get all embedded QR Codes
Dim results As IEnumerable(Of QrResult) = reader.Read(imageInput)' Load the asset into QrImageInput
Dim imageInput As New QrImageInput(capturedBitmap)
' Create a QR Reader object
Dim reader As New QrReader()
' Read the Input and get all embedded QR Codes
Dim results As IEnumerable(Of QrResult) = reader.Read(imageInput)Each call analyzes one still frame. Decode them back to back and the camera appears to scan live, even though IronQR only ever sees individual images.
Curtis Chau holds a Bachelor’s degree in Computer Science (Carleton University) and specializes in front-end development with expertise in Node.js, TypeScript, JavaScript, and React. Passionate about crafting intuitive and aesthetically pleasing user interfaces, Curtis enjoys working with modern frameworks and creating well-structured, visually appealing manuals.
