line-drawer

line-drawer recreates a given image by only drawing it by simple straight lines. In the table below you can see the demo image which has been drawn with 10000 lines within 40 seconds, once in the subtractive mode and once in the additive mode.

original image	subtractive mode	additive mode

Options

--input-path	Input image path.
--output-path	Output image path.
--num-lines	Number of lines to draw.
--line-heaviness	Line heaviness. Integer from 1 to 255, with 255 being completely heavy.
--num-lines-to-check	Number of lines to check at each iteration.
--draw-type	Draw types (subtractive/additive). Subtractive means white background with black lines. Additive means black background with with lines.
--no-random-result	Will return always the same output with the same config if set.
--output-width	Output image width in pixels where height will be adapted. Smaller width reduces computation time. "-1" will not change the size.
--output-format {PNG,SVG}	Output image format - PNG or SVG (default: PNG)
--stroke-width	SVG stroke width (default: 0.1)

Algorithm

The line-drawer is based on greedy algorithms where for a defined number of lines the best line positions are searched, to mimic the original images as good as possible. The algorithm works as follows:

For num-lines times
    Search the darkest pixel in image
    Select randomly one of the darkest pixels

    For num-lines-to-check times
        Get random line through previously selected pixel
    Select best fitting and save it to list

For every selected line
    Draw line in output image

Dependencies

• python 3
• see requirements.txt

Installation & Execution

pip3 install virtualenv
virtualenv venv
source venv/bin/activate
pip3 install -r requirements.txt

python src/line_drawer.py --input-path ./example/mani_matter.png --output-path ./out_image.png --num-lines 10000   

Unit tests

bash test.sh

Credits

• Basic idea (https://www.reddit.com/r/Art/comments/454joy/drawing_experiment_every_line_goes_through_the/)
• JavaScript implementation (http://linify.me/about)
• C++ implementation (https://github.com/nathanbain314/lineDrawer)
• Image from Mani Matter (Source: LP Album Cover — Mani Matter — I Han Es Zündhölzli Azündt — zytglogge Verlag)