Turn a PDF into an image using MuPDF - Trigger.dev

Overview

This example demonstrates how to use Trigger.dev to turn a PDF into a series of images using MuPDF and upload them to Cloudflare R2.

Update your build configuration

To use this example, add these build settings below to your trigger.config.ts file. They ensure that the mutool and curl packages are installed when you deploy your task. You can learn more about this and see more build settings here.

trigger.config.ts

export default defineConfig({
  project: "<project ref>",
  // Your other config settings...
  build: {
    extensions: [aptGet({ packages: ["mupdf-tools", "curl"] })],
  },
});

Task code

trigger/pdfToImage.ts

import { logger, task } from "@trigger.dev/sdk/v3";
import { PutObjectCommand, S3Client } from "@aws-sdk/client-s3";
import { execSync } from "child_process";
import fs from "fs";
import path from "path";

// Initialize S3 client
const s3Client = new S3Client({
  region: "auto",
  endpoint: process.env.S3_ENDPOINT,
  credentials: {
    accessKeyId: process.env.R2_ACCESS_KEY_ID ?? "",
    secretAccessKey: process.env.R2_SECRET_ACCESS_KEY ?? "",
  },
});

export const pdfToImage = task({
  id: "pdf-to-image",
  run: async (payload: { pdfUrl: string; documentId: string }) => {
    logger.log("Converting PDF to images", payload);

    const pdfPath = `/tmp/${payload.documentId}.pdf`;
    const outputDir = `/tmp/${payload.documentId}`;

    // Download PDF and convert to images using MuPDF
    execSync(`curl -s -o ${pdfPath} ${payload.pdfUrl}`);
    fs.mkdirSync(outputDir, { recursive: true });
    execSync(`mutool convert -o ${outputDir}/page-%d.png ${pdfPath}`);

    // Upload images to R2
    const uploadedUrls = [];
    for (const file of fs.readdirSync(outputDir)) {
      const s3Key = `images/${payload.documentId}/${file}`;
      const uploadParams = {
        Bucket: process.env.S3_BUCKET,
        Key: s3Key,
        Body: fs.readFileSync(path.join(outputDir, file)),
        ContentType: "image/png",
      };

      logger.log("Uploading to R2", uploadParams);

      await s3Client.send(new PutObjectCommand(uploadParams));
      const s3Url = `https://${process.env.S3_BUCKET}.r2.cloudflarestorage.com/${s3Key}`;
      uploadedUrls.push(s3Url);
      logger.log("Image uploaded to R2", { url: s3Url });
    }

    // Clean up
    fs.rmSync(outputDir, { recursive: true, force: true });
    fs.unlinkSync(pdfPath);

    logger.log("All images uploaded to R2", { urls: uploadedUrls });

    return {
      imageUrls: uploadedUrls,
    };
  },
});

Testing your task

To test this task in the dashboard, you can use the following payload:

{
  "pdfUrl": "https://pdfobject.com/pdf/sample.pdf",
  "documentId": "unique-document-id"
}

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