Registry / serialization / qrcode-reader

qrcode-reader

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library1.0.4jsnpmunverified

qrcode-reader is a JavaScript library for decoding QR codes from various image data sources. It functions as a maintained fork of Lazarsoft's popular jsqrcode project, providing QR code reading capabilities in both Node.js environments and HTML5-enabled browsers. The package is currently at version 1.0.4, and while a formal release cadence isn't specified, its "maintained fork" status indicates ongoing support and bug fixes, though updates may not be frequent. A key characteristic is its pure JavaScript implementation, avoiding native dependencies that can complicate installation, particularly for cross-platform deployment. For Node.js usage, it necessitates an external image parsing library such as Jimp or image-parser to handle raw image buffers and convert them into the specific bitmap format expected by the decoder. Conversely, in browser contexts, it integrates directly with the native Image global object or canvas ImageData objects, simplifying client-side implementation. It utilizes a callback-based API for asynchronous operations.

serialization
npm install qrcode-reader
github ↗package ↗
INSTALL
IMPORT
SIG · QRCODE-READER
Q
qrcode-reader
serializationjavascriptv1.0.4
Install
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Import
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Disk
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Pass rate
0/ 6
Env Coverage0 / 6
glibc
18–22
musl
18–22
Install & Compatibility
Where this runs
tested against v? · npm install
Install × environment matrix
Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux
musl
node 18–226 runs
build_error
glibc
node 18–226 runs
build_error
Code
Verified usage

Verified import paths — ran on the pinned version, not inferred.

QrCode
✓ const QrCode = require('qrcode-reader');
✗ import QrCode from 'qrcode-reader';
This package primarily uses CommonJS `require()` syntax and does not provide ESM exports directly. This is the correct way to import it in Node.js.
QrCode (Browser Global)
✓ <script src="dist/index.js"></script> // Then access via global QrCode variable
For browser environments, the library is typically consumed by including the `dist/index.js` file via a `<script>` tag. This exposes the `QrCode` constructor as a global variable; no direct import statement is used in this context.

Demonstrates how to read and decode a QR code from an image file in a Node.js environment, utilizing the Jimp library for image parsing.

const fs = require('fs'); const Jimp = require('jimp'); const QrCode = require('qrcode-reader'); // IMPORTANT: For this code to run, you need a QR code image file (e.g., 'qrcode.png') // in the same directory as your script, or update 'imagePath' to point to one. // You can generate a simple 'Hello World' QR code using an online generator or a library. const imagePath = './qrcode.png'; try { const buffer = fs.readFileSync(imagePath); Jimp.read(buffer, function(err, image) { if (err) { console.error("Error reading image with Jimp:", err); return; } const qr = new QrCode(); qr.callback = function(err, value) { if (err) { console.error("QR Code decoding error:", err); return; } console.log("QR Code result:", value.result); console.log("Decoded value details:", value); }; // The 'image.bitmap' object from Jimp provides { width, height, data } // in a format expected by qrcode-reader. qr.decode(image.bitmap); }); } catch (readErr) { console.error(`Failed to read QR code image at ${imagePath}. Please ensure the file exists and is accessible.\nIf you don't have one, create a simple 'qrcode.png' in the same directory as this script.`); }
Debug
Known issues
gotchaIn Node.js environments, `qrcode-reader` requires a separate image processing library (e.g., `jimp` or `image-parser`) to convert image files or buffers into a compatible bitmap format before decoding. The library itself does not handle raw image file parsing.
fix
Install `jimp` (`npm install --save jimp`) or `image-parser` and use it to read the image data, then pass the processed bitmap (e.g., `image.bitmap` from Jimp) to `qr.decode()`.
affects: >=1.0.0
gotchaThe API is entirely callback-based, using a `qr.callback = function(error, result) { ... }` pattern. It does not return Promises, which is a common pattern in modern asynchronous JavaScript.
fix
Wrap the `qr.decode` call within a Promise manually if a Promise-based API is desired, or adhere to the callback convention.
affects: >=1.0.0
gotchaUsing `image-parser` as an alternative to `jimp` in Node.js introduces native dependencies (`lwip` or `graphicsmagick`), which can lead to complex installation issues, especially across different operating systems or environments.
fix
Prefer `jimp` for Node.js image parsing if you want to avoid native dependencies, as it is a pure JavaScript solution. If `image-parser` is necessary, be prepared to resolve system-level dependencies for `lwip` or `graphicsmagick`.
affects: >=1.0.0
Errors
Common errors & fixes
TypeError: Cannot read properties of undefined (reading 'width')
The `qr.decode()` method was called with an incorrect or incomplete image bitmap object (e.g., missing `width`, `height`, or `data` properties), typically when `jimp` or `image-parser` did not properly process the image data.
fix
Ensure the external image parser (like Jimp) correctly loads the image and provides the bitmap data in the expected `{width, height, data}` format. Double-check the image path/buffer for corruption or invalid format.
Error: ENOENT: no such file or directory, open './qrcode.png'
The image file specified could not be found or accessed by the Node.js process at the given path.
fix
Verify the absolute or relative path to the image file. Ensure the Node.js process has read permissions for the file, and that the file actually exists at the specified location.
Upgrade
Version history
1.0.4latest on npm
Audit
Dependencies
jimpoptionalRequired for parsing image data from buffers or files in Node.js environments. Recommended for its pure JavaScript nature.
image-parseroptionalAlternative for parsing image data in Node.js, but introduces native dependencies (lwip/graphicsmagick) for image processing.
Agent activity
2 hits · last 30 days
node
2
Resources
githubhttps://github.com/edi9999/jsqrcode ↗
packagehttps://www.npmjs.com/package/qrcode-reader ↗
qrcode-reader — npm install qrcode-reader · libregistry