PDF a imágenes

import * as pdfjsLib from "pdfjs-dist";
import workerUrl from "pdfjs-dist/build/pdf.worker.min.mjs?url";

pdfjsLib.GlobalWorkerOptions.workerSrc = workerUrl;

// pageNumber es 1-based; scale controla la resolución (2 aprox. alta calidad).
export async function renderPdfPageToPng(file: File, pageNumber: number, scale = 2): Promise<string> {
  const data = new Uint8Array(await file.arrayBuffer());
  const pdf = await pdfjsLib.getDocument({ data }).promise;
  const page = await pdf.getPage(pageNumber);

  const viewport = page.getViewport({ scale });
  const canvas = document.createElement("canvas");
  const context = canvas.getContext("2d");
  if (!context) {
    throw new Error("No se pudo obtener el contexto 2D del canvas.");
  }

  canvas.width = Math.ceil(viewport.width);
  canvas.height = Math.ceil(viewport.height);

  await page.render({ canvas, canvasContext: context, viewport }).promise;
  await pdf.destroy();

  return canvas.toDataURL("image/png");
}