Limit Tesseract OCR Character Recognition: Tips & Tricks

Tesseract OCR is a powerful tool for character recognition, but sometimes you may want to limit its recognition capabilities to improve accuracy and speed. Here are some tips and tricks to help you achieve this:

1. Specify the language

By default, Tesseract OCR recognizes characters in multiple languages. To limit its recognition to a specific language, you can specify the language using the -l option followed by the language code. For example, tesseract image.png output -l eng limits recognition to English characters.

2. Use page segmentation mode

Page segmentation mode defines how Tesseract OCR analyzes the image to identify characters. By default, Tesseract OCR uses automatic page segmentation mode, which may not always be accurate. You can use --psm option followed by a page segmentation mode value to improve accuracy. For example, tesseract image.png output --psm 6 uses the fully automatic page segmentation mode with orientation and script detection.

3. Apply image preprocessing techniques

Image preprocessing techniques can improve recognition accuracy by enhancing the quality of the image. You can try techniques such as binarization, thresholding, and noise reduction to improve image quality before feeding it to Tesseract OCR.

4. Train Tesseract OCR

If you have a specific set of characters to recognize, you can train Tesseract OCR to improve recognition accuracy. Tesseract OCR provides a training tool called tesseract-trainer that allows you to create a custom language model for character recognition.

Conclusion

By using these tips and tricks, you can limit Tesseract OCR character recognition to improve accuracy and speed. Specify the language, use page segmentation mode, apply image preprocessing techniques, and train Tesseract OCR to achieve better results.