
Mono Captcha
Let's teach Stephan to recognize simple numbers. The Robots use monospaced fonts with low resolution. You can see the font on the picture below. This font has noise immunity to one-pixel error.
Your program should read the number shown in an image encoded as a binary matrix. Each digit can contain a wrong pixel, but no more than one for each digit. The space between digits is equal to one pixel (just think about "1" which is narrower than other letters, but has a width of 3 pixels).
Input: An image as a list of lists with 1 or 0.
Output: The number as an integer.
Example:
checkio([[0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0], [0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0], [0, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0], [0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0], [0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0]]) == 394 checkio([[0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0], [0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0], [0, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0], [0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0], [0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0]]) == 394
How it is used: This task will show you how optical character recognition works and will familiarize you with low-resolution fonts requiring noise-immunity. This can be useful for the systems that required the reliability.
Precondition:
matrix_rows == 5
5 ≤ matrix_columns < 30
∀ x ∈ matrix : x == 0 or x == 1
digit_width == 3
Each digit contains no more than one wrong pixel.
digits_space == 1
CheckiO Extensions allow you to use local files to solve missions. More info in a blog post.
In order to install CheckiO client you'll need installed Python (version at least 3.8)
Install CheckiO Client first:
pip3 install checkio_client
Configure your tool
checkio --domain=py config --key=
Sync solutions into your local folder
checkio sync
(in beta testing) Launch local server so your browser can use it and sync solution between local file end extension on the fly. (doesn't work for safari)
checkio serv -d
Alternatevly, you can install Chrome extension or FF addon
checkio install-plugin
checkio install-plugin --ff
checkio install-plugin --chromium
Read more here about other functionality that the checkio client provides. Feel free to submit an issue in case of any difficulties.