OMR Grader

Grader for bubble sheet multiple choice tests using Optical Mark Recognition, Python, and OpenCV. Images should be 300 dpi for maximum accuracy.

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes.

Prerequisities

• Python 3
• OpenCV 3.4.3 or later
• NumPy
• imutils
• SciPy (Windows only)
• ZBar
• pyzbar

Installing on Mac/Linux

To install the libraries, run the following commands:

$ brew install python3
$ pip install opencv-python
$ pip install numpy
$ pip install imutils
$ brew install zbar
$ pip install pyzbar

Installing on Windows Subsystem for Linux

To install the libraries, run the following commands:

$ apt install python3
$ apt install python3-opencv
$ apt install python3-pip
$ pip3 install numpy
$ pip3 install scipy
$ pip3 install imutils
$ sudo apt-get install libzbar-dev libzbar0
$ pip3 install pyzbar

Running

$ python grader.py -i path [-v] [-d] [-s scale]

Flags

• -i path: path to image file
• [-v]: enable verbose mode - program will return image slices for every question
• [-d]: enable debug mode - program will display image slices to screen
• [-s scale]: factor to scale image slices by

Acknowledgements

• Adrian Rosebrock's tutorial "Bubble sheet multiple choice scanner and test grader using OMR, Python, OpenCV"
• John Fremlin's tutorial "Rotating an image with OpenCV and Python"