answer_sheet_scanner

A Python 3.5 script to scan an answer sheet outputting the alternatives marked.

Dependencies:

• OpenCV

  • Package opencv-python (tested with version 3.3.0.10)
  • Recommended install method: "pip install opencv-python"

• Zbar(Not being used anymore)

  • Package zbar-py (tested with version 1.0.4)
  • Recommended install method: "pip install zbar-py"

Answer Sheet

The script expects determined markers to be present in the answer sheet. The .xcf Gimp Project file contains an example of what the answer sheet is expected to contain.

• Markers description:
  • It is expected to exist a barcode with the metadata for that answer sheet. It can be a QRcode, code 39 or any 2D code supported by the zbar library used. It reads the student identification using digits recognition from a specific part of the card v1.3.
  • There must be four triangle markers, forming a rectangle region in which must be all the questions.
  • Each question must have a question marker consisting of a rectangle with black contour and filled half black.
  • All question markers must be at a determined distance from the beggining of the alternatives regions. This can be adjusted in the "define_alternatives_region" function's source code.
  • Every alternative must be at the same distance from each other.

Usage

Try "python answersheet_scanner.py -h"

Debugging

The helper module cv2_utils.py has a variable called DEBUG, normally set to False. Set it to True or use the "--debug" switch to enable showing the various phases of the process through "cv2.imshow".