tesseract.js
Advanced tools
tesseract.js is a JavaScript library that provides Optical Character Recognition (OCR) capabilities. It allows you to extract text from images and PDFs directly in the browser or in a Node.js environment.
Basic OCR
This feature allows you to perform basic OCR on an image file. The code sample demonstrates how to recognize text from an image using the English language.
const Tesseract = require('tesseract.js');
Tesseract.recognize(
'path/to/image.png',
'eng',
{
logger: m => console.log(m)
}
).then(({ data: { text } }) => {
console.log(text);
});Handling Multiple Languages
This feature allows you to recognize text in multiple languages. The code sample demonstrates how to recognize text from an image using both English and Spanish languages.
const Tesseract = require('tesseract.js');
Tesseract.recognize(
'path/to/image.png',
'eng+spa',
{
logger: m => console.log(m)
}
).then(({ data: { text } }) => {
console.log(text);
});Progress Reporting
This feature provides real-time progress updates during the OCR process. The code sample demonstrates how to log progress messages to the console.
const Tesseract = require('tesseract.js');
Tesseract.recognize(
'path/to/image.png',
'eng',
{
logger: m => console.log(m)
}
).then(({ data: { text } }) => {
console.log(text);
});Using Worker for Performance
This feature allows you to use a worker for better performance, especially for large images or multiple OCR tasks. The code sample demonstrates how to create a worker, load the necessary language, perform OCR, and then terminate the worker.
const { createWorker } = require('tesseract.js');
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('path/to/image.png');
console.log(text);
await worker.terminate();
})();ocrad.js is a JavaScript port of the OCRAD OCR library. It is designed to be used in the browser and can recognize text from images. Compared to tesseract.js, ocrad.js is lighter but may not be as accurate or feature-rich.
node-tesseract-ocr is a Node.js wrapper for the Tesseract OCR engine. It provides a simpler interface for performing OCR in Node.js environments. While it offers similar functionalities to tesseract.js, it does not support browser usage.
Tesseract.js is a javascript library that gets words in almost any language out of images. (Demo)
Image Recognition
Video Real-time Recognition
Tesseract.js wraps a webassembly port of the Tesseract OCR Engine. It works in the browser using webpack or plain script tags with a CDN and on the server with Node.js. After you install it, using it is as simple as:
import Tesseract from 'tesseract.js';
Tesseract.recognize(
'https://tesseract.projectnaptha.com/img/eng_bw.png',
'eng',
{ logger: m => console.log(m) }
).then(({ data: { text } }) => {
console.log(text);
})
Or using workers (recommended for production use):
import { createWorker } from 'tesseract.js';
const worker = await createWorker({
logger: m => console.log(m)
});
(async () => {
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();
})();
For a basic overview of the functions, including the pros/cons of different approaches, see the intro. Check out the docs for a full explanation of the API.
Version 4 includes many new features and bug fixes--see this issue for a full list. Several highlights are below.
createWorker is now asyncgetPDF function replaced by pdf recognize optionRead a story about v2: Why I refactor tesseract.js v2?
Check the support/1.x branch for version 1
Tesseract.js works with a <script> tag via local copy or CDN, with webpack via npm and on Node.js with npm/yarn.
<!-- v4 -->
<script src='https://cdn.jsdelivr.net/npm/tesseract.js@4/dist/tesseract.min.js'></script>
After including the script the Tesseract variable will be globally available.
Requires Node.js v14 or higher
# For latest version
npm install tesseract.js
yarn add tesseract.js
# For old versions
npm install tesseract.js@3.0.3
yarn add tesseract.js@3.0.3
The following are old examples that use depreciated versions of Tesseract.js. Updating to Tesseract.js v4 is highly recommended. Users are encouraged to create updated examples (or make entirely new ones) and submit them as pull requests.
React Native is not supported as it does not support Webassembly.
To run a development copy of Tesseract.js do the following:
# First we clone the repository
git clone https://github.com/naptha/tesseract.js.git
cd tesseract.js
# Then we install the dependencies
npm install
# And finally we start the development server
npm start
The development server will be available at http://localhost:3000/examples/browser/demo.html in your favorite browser.
It will automatically rebuild tesseract.dev.js and worker.dev.js when you change files in the src folder.
You can use Gitpod(A free online VS Code like IDE) for contributing. With a single click it will launch a ready to code workspace with the build & start scripts already in process and within a few seconds it will spin up the dev server so that you can start contributing straight away without wasting any time.
To build the compiled static files just execute the following:
npm run build
This will output the files into the dist directory.
This project exists thanks to all the people who contribute. [Contribute].
Become a financial contributor and help us sustain our community. [Contribute]
Support this project with your organization. Your logo will show up here with a link to your website. [Contribute]
FAQs
Pure Javascript Multilingual OCR
The npm package tesseract.js receives a total of 23,094 weekly downloads. As such, tesseract.js popularity was classified as popular.
We found that tesseract.js demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 4 open source maintainers collaborating on the project.
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