Image to PDF

import { PDFDocument } from "pdf-lib";

// Each image (PNG or JPG) is added as a page sized to the image.
export async function imagesToPdf(files: File[]): Promise<Uint8Array> {
  const pdf = await PDFDocument.create();

  for (const file of files) {
    const bytes = new Uint8Array(await file.arrayBuffer());
    const isPng = file.type === "image/png" || file.name.toLowerCase().endsWith(".png");
    const image = isPng ? await pdf.embedPng(bytes) : await pdf.embedJpg(bytes);
    const page = pdf.addPage([image.width, image.height]);
    page.drawImage(image, { x: 0, y: 0, width: image.width, height: image.height });
  }

  return pdf.save();
}