How to Detect QR Codes When Processing the Pixels of an Image?

BarcodeBC > Articles > How to Detect QR Codes When Processing the Pixels of an Image?

Detect QR Codes When Processing the Pixels of an Image

If you need to detect QR Codes when processing the pixels of an image, you can use a .NET QR Code detection library. Here's a basic example of how to detect QR Codes using ZXing.Net.

In this example, we load the image as a Bitmap object, convert it to a luminance source, create a binary bitmap from the luminance source using a hybrid binarizer, and then create a QR Code detector using ZXing.Net's BarcodeReader class with the QrCodeReadingOptions set to specify the error correction level and character set. Finally, we decode the QR Code from the binary bitmap and check if a QR Code was detected.

using ZXing;
using ZXing.Common;
using ZXing.QrCode;
using System.Drawing;

// Load the image as a bitmap
Bitmap bitmap = new Bitmap("path/to/image.jpg");

// Convert the bitmap to a luminance source
var luminance = new BitmapLuminanceSource(bitmap);

// Create a binary bitmap from the luminance source
var binary = new HybridBinarizer(luminance).ToBitmap();

// Create a QR Code detector
var reader = new BarcodeReader
    Options = new QrCodeReadingOptions
        // Set the error correction level
        PossibleFormats = new List<BarcodeFormat> { BarcodeFormat.QR_CODE },
        CharacterSet = "UTF-8",
        TryHarder = true

// Decode the QR Code from the binary bitmap
var result = reader.Decode(binary);

// Check if a QR Code was detected
if (result != null)
    string text = result.Text;
    // Do something with the scanned QR Code text
    // No QR Code was detected

How to Detect QR Codes from Images in Go?

To detect QR Codes from images in Go, you can use the "" package. Here's an example code snippet that demonstrates how to use this package to detect QR Codes from an image.

In this example, the "qrcode.jpg" file contains the image to be scanned. The code first opens and decodes the image, then converts it to grayscale using the "ToGray" function from the "" package. Finally, it uses the "DecodeAll" function to detect any QR Codes in the image, and prints their contents to the console.

package main

import (


func main() {
	// Open the image file
	file, err := os.Open("qrcode.jpg")
	if err != nil {
	defer file.Close()

	// Decode the image
	img, _, err := image.Decode(file)
	if err != nil {

	// Convert the image to grayscale
	gray := qrcode.ToGray(img)

	// Detect the QR Codes in the image
	qrs, err := qrcode.DecodeAll(gray)
	if err != nil {

	// Print the QR Code contents
	for _, qr := range qrs {

Note that the "" package only supports QR Codes, and cannot detect other types of barcodes. If you need to detect other types of barcodes, you may need to use a different library or tool.

Besides ZXing.Net's BarcodeReader, there's another mature .NET QR Code barcode reader library for your reference: BC.NetBarcodeReader.Qrcode. And this is an online guide for using BC.NetBarcodeReader.Qrcode.