Author: Nathan Aday / nraday1221@gmail.com
https://github.com/nathanaday/RealTime-OCR
Perform text detection in a variety of languages with your computer webcam using Google Tesseract OCR and OpenCV. This script achieves a real-time OCR effect by incorporating multi-threading.
This a command-line script. The only required argument is a full path to the Tesseract executable from the Tesseract install (see DEPENDENCIES below for more info)
python Main.py -t '<full_path_to_your_tesseract_executable>' [-c ] [-v] [-sv] [-l] [-sl]
optional arguments:
-h, --help command-line argument help message
-c , --crop crop OCR area in pixels (two vals required): width height
-v , --view_mode view mode for OCR boxes display (default=1)
-sv, --show_views show the available view modes and descriptions
-l , --language code for tesseract language, use + to add multiple (ex: chi_sim+chi_tra)
-sl, --show_langs show list of tesseract (4.0+) supported langs
required named arguments: -t , --tess_path path to the cmd root of tesseract install (see docs for further help)
The crop area allows OCR to be performed on a smaller frame and therefore improves speed. A box is automatically drawn around the crop so it's clear where to position text for detection.
This script implements four view modes, which stylize the way text is detected. To specify a view mode, use -v after the Main.py call
(View mode 1: Draws boxes on text with >75 confidence level)
(View mode 2: Draws red boxes on low-confidence text and green on high-confidence text)
(View mode 3: Color changes according to each word's confidence; brighter indicates higher confidence)
View mode 4: Draws a box around detected text regardless of confidence
If no view mode is specified, the OCR will run with mode 1.
To see the view options and their descriptions in the command line, evoke -sv or --show_views
The OCR can detect a variety of langauges since version 4+. A language can be specified by appending the Main.py call with "-l "
For example, to detect simplified Chinese, use:
python Main.py -t '<full_path_to_your_tesseract_executable>' -l chi_sim
Multiple languages can be simultaneously detected by appending the codes with '+'
To detect both simplified chinese and traditional chinese, use:
python Main.py -t '<full_path_to_your_tesseract_executable>' -l chi_sim+chi_tra
A list of all the languages codes can be printed in the command line by evoking '-sl'.
python Main.py -t '<full_path_to_your_tesseract_executable>' -sl
Note, the printed list of available langauges comes from the tesseract supported languages, which should be included in an up-to-date install, but evoking the lagnauge code will have no effect if the .traindata file for that language is nowhere in the data files.
If no language code is specified, the OCR defaults to English.
This script requires:
- a Tesseract install
- the python wrapper for Teseract (pytesseract)
- OpenCV for python (CV2)
- Numpy
Instruction on how to install Tesseract on your OS are located here:
https://tesseract-ocr.github.io/tessdoc/Installation.html
To use the script, you will need the path to the exec file included in the Tesseract install, so note the install's location.
Example (on a Homebrew install): '/usr/local/Cellar/tesseract/4.1.1/bin/tesseract'
To install the Python wrapper for Tesseract, use:
pip install pytesseract
(See the pytesseract docs for further help.)[https://pypi.org/project/pytesseract/]
To install OpenCV for Python, use:
pip install opencv-python
(See the opencv-python docs for further help.)[https://pypi.org/project/opencv-python/]
For numpy, use:
pip install numpy
(See the numpy docs for further help.)[https://numpy.org/install/]
Tesseract should come with .traindata files that supports a wide variety of foreign languages. In any case, the repo for language files can be found here:
https://github.com/tesseract-ocr/tessdata
Main.py
- Command-line argparser and call to the OCR stream
OCR.py
- All classes and functions for multi-threaded text detection and webcam display
Linguist.py
- A few functions for handling the language codes and converting them to full language names (reads from Tesseract_Langs.txt)
Tesseract_Langs.txt
- Text file for every supported language code and the language's full name
README.md
requirements.txt
...
...
