Serial Number Reader Utility

This TypeScript utility provides functionality for detecting barcodes from an image file. It works primarily with browser-based applications and leverages the experimental BarcodeDetector API. Please note that this API is not universally supported across all browsers.

Install

$: npm i serial-number-reader

Demo

$ cd example
$ python3 -m http.server

# navigation to http://localhost:8000

Usage TLDR

import { readImageFile, detectSerialNumbers } from "serial-number-reader";

// example usage with file input
function getFileFromInputEvent(event: Event): File | null {
  return (<HTMLInputElement>event.target)?.files?.[0] || null;
}

async function handleFileInputChange(event: Event): Promise<void> {
  const file = getFileFromInputEvent(event);
  if (!file) {
    console.error("No file chosen");
    return;
  }

  try {
    const image = await readImageFile(file);
    const serialNumbers = await detectSerialNumbers(image);
    console.log(serialNumbers);

    // do something with image
  } catch (error) {
    console.error("Error reading file", error);
  }
}

const fileInputElement = document.querySelector('input[type="file"]');
fileInputElement.addEventListener("change", handleFileInputChange);

Features

This utility includes the following features:

1. Barcode Interface: A TypeScript interface Barcode representing a barcode with a raw value.

2. BarcodeDetector Class: A wrapper around the experimental BarcodeDetector API, providing a detect method that takes an ImageBitmapSource and returns a Promise of an array of Barcode.

3. Image File Reader: An async function readImageFile that takes an event (usually from an input of type file), reads the file as a Blob, creates an Image object, and returns a Promise of HTMLImageElement.

4. Barcode Detection from Image: An async function detectSerialNumber that takes an ImageBitmapSource and returns a Promise of an array of serial numbers extracted from the detected barcodes in the image.

5. File to Blob Converter: A function readFileAsBlob that reads a File as an ArrayBuffer, then creates a Blob with the file type, and returns a Promise of the Blob.

6. Barcode Detection Wrapper: A function detectBarcodes that creates a new BarcodeDetector for a specified set of barcode formats, detects barcodes in the provided ImageBitmapSource, and returns a Promise of an array of detected Barcode objects.

In the detectBarcodes function, the barcodeTypes parameter defaults to ['code_39', 'codabar', 'ean_13'], but you can specify other types if needed. It uses a defined type BarcodeType which allows for these specific values only: 'aztec', 'code_128', 'code_39', 'code_93', 'codabar', 'data_matrix', 'ean_13', 'ean_8', 'itf', 'pdf417', 'qr_code', 'upc_a', 'upc_e'.

const barcodes = await detectBarcodes(image, ["ean_8", "code_128"]);

Please note that the Barcode Detector API is experimental and may not be supported on all browsers. Always check for the existence of BarcodeDetector in the global scope before usage.

Dependencies

No external dependencies are required. This utility uses native browser APIs and TypeScript. However, please make sure you have TypeScript installed and configured properly.

Browser Compatibility

Please refer to the official documentation for the most current browser compatibility information. As of the last update, the API is supported on Chrome and Edge (desktop) only.

Contributions

If you encounter any issues or want to contribute, feel free to open an issue or a pull request.

License

This project is open source and available under the MIT License.