retro-pdf417

A PDF417 barcode writer (encoder only) that mimics the behaviour of the original writer used by NADRA for the barcode on Pakistani CNICs.

It produces a PNG barcode that matches what the original writer would produce.

Writer only. This package cannot read or decode barcodes.

It can also encode other kinds of data, but it is not a general-purpose PDF417 library. If you are not trying to reproduce NADRA CNIC barcodes, you are better off using zxing-wasm.

Installation

npm install retro-pdf417

Usage

import { writeFileSync } from "node:fs"
import { generateBarcode } from "retro-pdf417"

const bytes = new TextEncoder().encode("your data here")

const png = generateBarcode(bytes, { scale: 4 })
writeFileSync("barcode.png", png)

generateBarcode returns the PNG as a Uint8Array.

Options

| Option | Default | Description | | ----------- | ------- | ------------------------------------------- | | scale | 1 | Size of each barcode module in pixels. | | margin | 4 | Margin around the barcode in pixels. | | rowRepeat | 3 | Repeats each row a certain number of times. |

Other functions

If you want to draw the barcode yourself instead of getting a PNG, you can use the lower-level steps:

import { generateCodeWords, generateBitMatrix } from "retro-pdf417"

const { codewords, columnCount } = generateCodeWords(bytes)
const matrix = generateBitMatrix(codewords, columnCount, { scale: 4 })
// matrix is a list of rows where 1 is a dark module and 0 is light

Limitations

• Always uses error correction level 4.
• Targets 20 rows, with at most 30 columns (larger inputs throw error).