**Last Update**: 26.05.2024
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- Tess4J is a Java JNA wrapper for Tesseract OCR API
- Tesseract is an excellent open-source tool for character recognition, but direct usage in Java can require a lot of setup. By using Tess4J, you can access Tesseract's capabilities with simple Java calls.
- The Tesseract class in Tess4J are not designed to be thread-safe. This means that you should not use the same instance of this class simultaneously from multiple threads.
```java
import net.sourceforge.tess4j.*;
public class Example {
public static void main(String[] args) {
File imageFile = new File("myimage.png"); // replace this with your image
ITesseract instance = new Tesseract(); // JNA Interface Mapping
instance.setDatapath("tessdata"); // path to tessdata directory
try {
String result = instance.doOCR(imageFile);
System.out.println(result);
} catch (TesseractException e) {
System.err.println(e.getMessage());
}
}
}
```
> [!NOTE]
> Note that using Tesseract and Tess4J requires you to have the [Tesseract OCR engine installed on your machine](https://tesseract-ocr.github.io/tessdoc/Installation.html). Since Tess4J is just a wrapper around this engine, it won't work without it.
In a practical scenario, you can use it to recognize and decipher CAPTCHA images, which are often used for testing whether the user is human. [Here](https://github.com/ehayik/web-scraping-kata/blob/master/src/main/java/org/github/ehayik/kata/webscraping/technicalreview/CaptchaWidget.java) is a link to a code example using Selenium WebDriver.
> [!WARNING]
> However, always remember to respect CAPTCHAs -- they are in place for a reason. Please do not use Tess4J or any OCR software to attempt to bypass them.
***
**References**:
- [Tess4J](https://github.com/nguyenq/tess4j)
- [Tesseract OCR](https://github.com/tesseract-ocr/tesseract)
- [Optical Character Recognition with Tesseract](https://www.baeldung.com/java-ocr-tesseract)