A GNU/Octave tool to digitize paper surveys.
The purpose of this project is to have a tool to digitize (aka digitalize) surveys in paper format, transforming them into a CSV file. The expected format for the survey is the following type of questionaire.
| Questions | Answers |
|---|---|
| Question1 | 1 2 |
| Question2 | 1 |
Disclaimer: methods such as digit recognition, OCR or artificial intelligence are not used in this project (so far).
The idea behind the digitalization algorithm is rather simple. Basically, the script will be provided regions where the numbered answers are placed. Then it will measure the amount of ink in every region, taking as the marked answer the region that contains the most ink in the row.
Of course, the algorithm has been optimized to avoid false positives, as well as to avoid false negatives, even when two or more answers are marked for a single question.
- First, you need to get and install GNU/Octave. The signal package is used within this project.
- Then, you have to add the centers of every region in
get_centers.m. This file works on a x/y-axis basis. - When everything is set up, you can run
surveys.mfrom GNU/Octave. You may need to adjust the first lines (custom variables) before running it.
You're all set! You should now have a beautiful CSV file with the answers of your survey.
The script takes a while to run, that's true... I guess image processing is always kind of heavy stuff. Apart from this, the script performs pretty well (as far as I've measured). First results suggest a precission over 95% with scanned paper questinaires.
I started this project becausge I didn't know any specific tool to perform this
task in the Open Source community. This project is Free Software (see
LICENSE) and you're very welcome to make contributions (enhancing the
documentation, usability, the algorithm itself, asking for new features...
whatever!).