etch-a-sketch-vectorizer

The goal of this project is to convert an image into a vectorized path so that a robot can draw the image on a real-life etch-a-sketch.

How to Contribute

Unless someone really wants to, I am not going to manage pull requests. If you want to contribute, contact me (Alan Koval) with your github account info and I will add you as a contributor. Please adhere to the following guidelines to maintain some semblance of organization in this repository:

1. After cloning the repo, make a branch that you will put all your work on. Include your name in the branch name, and push the branch back to the repo. For example:

    git checkout -b alan-koval       # make new branch including my name
    git push -u origin alan-koval    # push the branch
   

   Do your work on your branch and merge to and from master when you deem fit.

2. Make a separate folder for any sub-projects. Use descriptive names.

3. Inside your project folders, include a .txt or .md file detailing how to run your program. This includes what compilers/packages you would need to install to get it to run it on a fresh Ubuntu installation. Ideally include exactly what kind of input your program expects and what it will output.

4. If you finish a feature, experimental or not, edit this readme with a short description of what it does.

So that everyone can use their favorite programming language, restrict your input when possible to language-agnostic file types. I would recommend using .json files for output data; most languages have decent serialization libraries (i.e. Java's gson, Python's json package, JSON.parse(...) in JavaScript, etc).

Problem Statement

Input

1. An image. Can be .png, .bmp or other lossless format.
2. A value of alpha_L, the signed proportion of the width of the etch-a-sketch traversed when the left stepper motor is rotated by 1 rad in the counterclockwise direction. By signed we mean that that alpha_L < 0 if and only if the pointer moves to the left when the stepper motor is rotated in the counterclockwise direction.
3. A value of alpha_R, the signed proportion of the height of the etch-a-sketch traversed when the left stepper motor is rotated by 1 rad in the counterclockwise direction.

Required Output

A .json file enumerating a sequence of stepper motor commands. Each command must give a left knob angular velocity, a right knob angular velocity, and a duration of the command in seconds. When fed to a machine that executes the commands in order on a real etch-a-sketch, the machine must produce on the etch-a-sketch a visually appealing rendition of the input image.

Emulator

See emulator folder. Takes a simple .json input file with line segments and converts it into an image fle of what it may look like on a real etch-a-sketch. Here's an example of what it outputs:

Path Union Tool

See path_union folder. A central constraint of an etch-a-sketch is its inability to pick up its head and move somewhere else without drawing. This tool converts an arbitrary set of paths on the plane to a single path by computing a minimum spanning tree of the input paths and traversing the resulting tree. The resulting path is drawable by an etch-a-sketch in that it is composed of a single connected path and minimizes any drawing that was not in the original paths.