Node.js

Scanic runs on the server too. Because it relies on the Canvas API and a few DOM globals, you provide a canvas implementation (canvas, aka node-canvas) and a DOM environment (jsdom).

Install

npm

npm install scanic canvas jsdom

pnpm

pnpm add scanic canvas jsdom

yarn

yarn add scanic canvas jsdom

Setup & scan

Wire up the globals Scanic expects, then call it as usual:

import { scanDocument } from 'scanic'
import { loadImage } from 'canvas'
import { JSDOM } from 'jsdom'

// Provide a minimal DOM environment
const dom = new JSDOM()
global.document = dom.window.document
global.ImageData = dom.window.ImageData

const img = await loadImage('document.jpg')
const result = await scanDocument(img, { mode: 'extract', output: 'imagedata' })

if (result.success) {
  console.log('Corners:', result.corners)
  // result.output is ImageData; draw it onto a node-canvas to save it
}

Saving the result to a file

Use output: 'canvas'-style data by drawing the returned ImageData onto a node-canvas and writing a PNG:

import { createCanvas } from 'canvas'
import { writeFileSync } from 'node:fs'

const out = result.output // ImageData
const canvas = createCanvas(out.width, out.height)
canvas.getContext('2d').putImageData(out, 0, 0)
writeFileSync('scanned.png', canvas.toBuffer('image/png'))

Reuse a Scanner for batches

Processing many files? Create one Scanner and call scanner.scan() per image so the WASM module is initialized only once.

WASM in Node

Scanic's WASM is inlined and decoded with Buffer when no global atob is available, so it works in Node without any extra configuration. If the runtime can't run it, Scanic falls back to pure JavaScript automatically.