# Tesseract.js (OCR)

Links: [Home](../../../index.md)

Wrapper for [Tesseract.js](https://tesseract.projectnaptha.com/) -- Optical Character Recognition (OCR) in the browser. Extracts text from images.

## Loading

```js
Application.require("thirdparty/convert/image/ocr/tesseract").then(function (Tesseract) {
    // Tesseract is the global Tesseract.js object
});
```

## Use Cases

### Extract text from an image

```js
Application.require("thirdparty/convert/image/ocr/tesseract").then(function (Tesseract) {
    Tesseract.recognize(document.getElementById('receipt-image'), 'eng')
    .then(function (result) {
        console.log('Extracted text:', result.data.text);
        console.log('Confidence:', result.data.confidence, '%');
    });
});
```

### OCR with progress tracking

```js
Application.require("thirdparty/convert/image/ocr/tesseract").then(function (Tesseract) {
    var worker = Tesseract.createWorker({
        logger: function (info) {
            if (info.status === 'recognizing text') {
                document.getElementById('progress').style.width = (info.progress * 100) + '%';
            }
        }
    });

    worker.load()
    .then(function () { return worker.loadLanguage('eng'); })
    .then(function () { return worker.initialize('eng'); })
    .then(function () { return worker.recognize(imageData); })
    .then(function (result) {
        console.log(result.data.text);
        return worker.terminate();
    });
});
```

### Extract text from a specific region

```js
Application.require("thirdparty/convert/image/ocr/tesseract").then(function (Tesseract) {
    Tesseract.recognize(imageElement, 'eng', {
        rectangle: { top: 0, left: 0, width: 200, height: 50 }
    }).then(function (result) {
        console.log('Header text:', result.data.text);
    });
});
```

## Notes

- First call downloads the Tesseract WASM binary and language data (~2 MB for English).
- Supports 100+ languages via language packs.
- Input can be: image element, canvas, file, Blob, or URL.
- Reference: [tesseract.projectnaptha.com](https://tesseract.projectnaptha.com/)