FAQ

How does tesseract.js download and keep *.traineddata?

The language model is downloaded by worker.loadLanguage() and you need to pass the langs to worker.initialize().

During the downloading of language model, Tesseract.js will first check if *.traineddata already exists. (browser: IndexedDB, Node.js: fs, in the folder you execute the command) If the *.traineddata doesn't exist, it will fetch *.traineddata.gz from tessdata, ungzip and store in IndexedDB or fs, you can delete it manually and it will download again for you.

How can I train my own *.traineddata?

For tesseract.js v2, check TrainingTesseract 4.00

For tesseract.js v1, check Training Tesseract 3.03–3.05

How can I get HOCR, TSV, Box, UNLV, OSD?

Starting from 2.0.0-beta.1, you can get all these information in the final result.

import { createWorker } from 'tesseract.js';
const worker = createWorker({
  logger: m => console.log(m)
});

(async () => {
  await worker.load();
  await worker.loadLanguage('eng');
  await worker.initialize('eng');
  await worker.setParameters({
    tessedit_create_box: '1',
    tessedit_create_unlv: '1',
    tessedit_create_osd: '1',
  });
  const { data: { text, hocr, tsv, box, unlv } } = await worker.recognize('https://tesseract.projectnaptha.com/img/eng_bw.png');
  console.log(text);
  console.log(hocr);
  console.log(tsv);
  console.log(box);
  console.log(unlv);
})();