In this article, we will use and compare the accuracy of Tesseract and EasyOcr as free popular OCR Engines.

WHY DO WE NEED OCR

Optical Character Recognition (OCR) becomes more popular as document digitalization evolves. More and more companies are looking for automating documentation, and OCR plays a vital role in processing image-based documents. Common use-cases are:

• Extracting text from Pictures
• Converting handwritten messages or notes

GETTING STARTED WITH TESSERACT OCR

The following steps would guide you through setting up Tesseract on linux, performing ocr action on images.

1. Installing Tesseract

To install Tesseract on Debian or Ubuntu Linux distribution, use apt as shown below

apt-get install tesseract-ocr

2. Installing Language (Optional)

apt-get install tesseract-ocr-all

Usually, the tesseract comes with the english pack by default if you want all the language packs to be downloaded, you can run the following command.

3. Usage

tesseract imagename outputbase [-l lang] [--oem ocrenginemode] [--psm pagesegmode] [configfiles...]

For example OCR an image and printing on console

tesseract /home/auriga/Desktop/picture.png stdout

For more options like language, order, segmentation modes.

https://tesseract-ocr.github.io/tessdoc/Command-Line-Usage.html

4. Language Specific Wrapper

Tess4j: 

A Java JNA wrapper for Tesseract OCR API. Tess4J is released and distributed under the Apache License, v2.0 and is also available from Maven Central Repository.

Maven Dependency:

<dependency>
    <groupId>net.sourceforge.tess4j</groupId>
    <artifactId>tess4j</artifactId>
    <version>5.2.0</version>
</dependency>

Features:

The library provides optical character recognition (OCR) support for:

• TIFF, JPEG, GIF, PNG, and BMP image formats

• Multi-page TIFF images
• PDF document format

PYTESSERACT: 

Python-tesseract is a wrapper for Google’s Tesseract-OCR Engine. It is also useful as a stand-alone invocation script to tesseract.

Pip Installation:

pip install pytesseract

pip install -U git+https://github.com/madmaze/pytesseract.git

Features:

The library provides optical character recognition (OCR) support for:

• It can read all image types supported by the Pillow and Leptonica imaging libraries, including jpeg, png, gif, bmp, tiff, and others.
• Additionally, if used as a script, Python-tesseract will print the recognized text instead of writing it to a file.

GETTING STARTED WITH EasyOCR

The following steps would guide you through setting up EasyOCR on linux, performing ocr action on images.

Pre-Requisite:  You need Python and PyTorch pre-installed for further process.

1. Installing Pip

To install pip package manager on Debian or Ubuntu Linux distribution, use apt as shown below

apt install python3-pip

2. Installing EasyOCR

To install EasyOCR on Debian or Ubuntu Linux distribution, use pip as shown below

pip install easyocr

Or

pip install git+git://github.com/jaidedai/easyocr.git

2. Usage

easyocr -l en --detail 0 --paragraph True -f image.png

For example OCR an image and printing on console

easyocr -l en --detail 0 -f /home/auriga/Downloads/temp.jpg

For more options like language list, detector, recognizer, etc.

https://www.jaided.ai/easyocr/documentation/

Conclusions

As per my testing,

• Tesseract is preferable for CPU wheras EasyOCR for GPU machine.
• Tesseract works better on character level, while EasyOCR does a better job on words.