simple-image-to-pdf/index.ts

A simple image to PDF converter

import * as fs from 'fs';
import sizeOf from 'image-size'
import {PDFDocument} from 'pdf-lib'
import sharp from 'sharp';


enum types {
  JPG = 'jpg',
  JPEG = 'jpeg',
  PNG = 'png',
  WebP = 'webp',
  GIF = 'gif',
  AVIF = 'avif',
  TIFF = 'tiff',
  SVG = 'svg',
  HEIC = 'heic'
}

const genPDFPage = async (imgBuf: Buffer, doc: PDFDocument) => {
  const {type, width, height} = sizeOf(imgBuf)
  const page = doc.addPage([width, height])
  let image4;
  switch (type) {
    case types.PNG:
      image4 = await doc.embedPng(imgBuf)
      break
    case types.JPEG:
    case types.JPG:
      image4 = await doc.embedJpg(imgBuf)
      break
    default:
      // @ts-ignore
      const jpg = await sharp(imgBuf).toFormat(types.JPG).toBuffer()
      image4 = await doc.embedJpg(jpg)
  }

  page.drawImage(image4, {
    x: 0, y: 0, width, height
  })
}
const imageToPDF = async (pages: string[] = []) => {
  const doc = await PDFDocument.create()

  for (let index = 0; index < pages.length; index++) {
    const imgBuf = fs.readFileSync(pages[index])
    await genPDFPage(imgBuf, doc)
  }
  return await doc.save()
};


const sizes = {
  "4A0": [4767.87, 6740.79],
  "2A0": [3370.39, 4767.87],
  "A0": [2383.94, 3370.39],
  "A1": [1683.78, 2383.94],
  "A2": [1190.55, 1683.78],
  "A3": [841.89, 1190.55],
  "A4": [595.28, 841.89],
  "A5": [419.53, 595.28],
  "A6": [297.64, 419.53],
  "A7": [209.76, 297.64],
  "A8": [147.40, 209.76],
  "A9": [104.88, 147.40],
  "A10": [73.70, 104.88],
  "B0": [2834.65, 4008.19],
  "B1": [2004.09, 2834.65],
  "B2": [1417.32, 2004.09],
  "B3": [1000.63, 1417.32],
  "B4": [708.66, 1000.63],
  "B5": [498.90, 708.66],
  "B6": [354.33, 498.90],
  "B7": [249.45, 354.33],
  "B8": [175.75, 249.45],
  "B9": [124.72, 175.75],
  "B10": [87.87, 124.72],
  "C0": [2599.37, 3676.54],
  "C1": [1836.85, 2599.37],
  "C2": [1298.27, 1836.85],
  "C3": [918.43, 1298.27],
  "C4": [649.13, 918.43],
  "C5": [459.21, 649.13],
  "C6": [323.15, 459.21],
  "C7": [229.61, 323.15],
  "C8": [161.57, 229.61],
  "C9": [113.39, 161.57],
  "C10": [79.37, 113.39],
  "RA0": [2437.80, 3458.27],
  "RA1": [1729.13, 2437.80],
  "RA2": [1218.90, 1729.13],
  "RA3": [864.57, 1218.90],
  "RA4": [609.45, 864.57],
  "SRA0": [2551.18, 3628.35],
  "SRA1": [1814.17, 2551.18],
  "SRA2": [1275.59, 1814.17],
  "SRA3": [907.09, 1275.59],
  "SRA4": [637.80, 907.09],
  "EXECUTIVE": [521.86, 756.00],
  "FOLIO": [612.00, 936.00],
  "LEGAL": [612.00, 1008.00],
  "LETTER": [612.00, 792.00],
  "TABLOID": [792.00, 1224.00]
}

export default imageToPDF
export {imageToPDF as convert, sizes, types}