---
title: "QR Detection Example"
description: "QR code detection and decoding with Iris."
keywords: ["QR code", "detection", "decoding"]
---
# QR Detection
Demonstrates QR code detection and decoding using QrDetector.
```bash
cargo run --example qr_detection --features wgpu
```
## Source
```rust
// Demonstrates QR code detection and decoding using QrDetector.
// Loads a real image and searches for QR codes.
use burn::backend::wgpu::{Wgpu, WgpuDevice};
use iris::prelude::*;
fn main() -> Result<()> {
type Backend = Wgpu;
let device = WgpuDevice::default();
println!(
"Using compute backend: {}",
BurnUtils::backend_name::<Backend>()
);
// Load a real image to search for QR codes
let image: Image<Backend> = Image::open("assets/images/test_pattern.png", &device)?;
// Detect QR codes
let detector = QrDetector::new();
let qr_codes = detector.detect_and_decode(&image)?;
println!("Detected {} QR code(s):", qr_codes.len());
for qr in &qr_codes {
println!(" - Payload: '{}'", qr.payload);
println!(" Corners: {:?}", qr.corners);
}
if qr_codes.is_empty() {
println!(" (No QR codes found in test_pattern — expected)");
}
image.save("output_qr_detection.png")?;
println!("Saved input image to 'output_qr_detection.png'");
Ok(())
}
```