OCR – Image and PDF to Text using JavaScript and Appscript

Optical Character Recognition (OCR) is a technology that enables you to convert different types of documents, such as scanned paper documents, PDF files, or images captured by a digital camera, into editable and searchable data. In this article, we will explore how to use JavaScript and Appscript to perform OCR on images and PDFs to extract text from them.

Using JavaScript for OCR

JavaScript, with the help of various OCR libraries and APIs, can be used to perform OCR on images and PDFs. One popular library for OCR in JavaScript is Tesseract.js, which is a pure JavaScript port of the popular Tesseract OCR engine. With Tesseract.js, you can easily extract text from images and PDFs using client-side JavaScript.

Example code using Tesseract.js

      
const { createWorker } = Tesseract;
const worker = createWorker({
  logger: m => console.log(m)
});

(async () => {
  await worker.load();
  await worker.loadLanguage('eng');
  await worker.initialize('eng');
  const { data: { text } } = await worker.recognize('https://tesseract.projectnaptha.com/img/eng_bw.png');
  console.log(text);
  await worker.terminate();
})();
      
    

Using Appscript for OCR

Appscript is a scripting language developed by Google for automating various tasks in Google Workspace applications such as Google Sheets, Docs, and Drive. With Appscript, you can also perform OCR on images and PDFs stored in Google Drive using the built-in OCR feature of Google’s Cloud Vision API.

Example code using Appscript and Cloud Vision API

      
function imageToText() {
  var file = DriveApp.getFileById('YOUR_IMAGE_FILE_ID');
  var imageBlob = file.getBlob();
  var vision = CloudVision.Images;
  var req = {
    requests: [
      {
        image: {
          content: imageBlob.getBytes()
        },
        features: [
          {
            type: 'TEXT_DETECTION'
          }
        ]
      }
    ]
  };
  var results = vision.annotate(req);
  var text = results.responses[0].textAnnotations[0].description;
  Logger.log(text);
}
      
    

Conclusion

OCR is a powerful technology that can be leveraged using JavaScript and Appscript to extract text from images and PDFs. Whether you need to extract text for processing, analysis, or search, these tools provide a straightforward way to achieve this goal. By incorporating OCR into your web and app development projects, you can unlock new possibilities for working with textual content.