An ASP-based Nonogram Solver with uniqueness checking, as well as a GUI for creating, viewing, solving and editing Nonograms, with an integrated Image-to-Nonogram converter.

Setup

We recommend running this python application in a virtual environment. For example, you can do the following to set this up:

python -m venv .venv

source .venv/bin/activate

pip install -r requirements.txt

Nonogram GUI

You can start the interactive GUI with

python -m gui

By default, this will open the Nonogram Generator window, where you can create a black and white image that will be turned into a nonogram after pressing 'OK'. Alternatively, you can specify a nonogram encoding file to load at the start, skipping the generator. Lastly, you can give the name of a solver to immediately solve the loaded nonogram. Example uses:

python -m gui nonograms/example_04.txt

python -m gui nonograms/example_03.lp sbs-improved

Manual Solving

Inside the Nonogram GUI, you can try to solve a nonogram manually by left-clicking on the cells. Multiple cells can be changed at once by dragging the mouse cursor. You can also mark cells with an 'x' by right-clicking them. By default, unsatisfied hints are emphasized in red, you can disable this in the 'View' menu.

Automatic Solving

You can also use the computer to solve the nonogram for you with the 'Solver' menu. Here you can also enable uniqueness checking and have an option to find all solutions to a given nonogram. If a solver found multiple solutions, you can cycle through them using Ctrl + H and Ctrl + J, or the 'View' menu.

Nonogram Editing

You can change any row or column hint directly by clicking on it and entering a valid list of numbers, separated by spaces. You can also fill the grid arbitrarily and then turn that grid into a nonogram by pressing Ctrl + Shift + N, or by using the 'File/New from current solution' menu option. Resizing the nonogram is not supported, you need to use the Nonogram Generator to create a new one.

Nonogram Generator & Image-to-Nonogram converter

The Nonogram Generator opens when you launch the application without parameters, or by pressing Ctrl + N from inside the Nonogram GUI. Here you can create a nonogram yourself using the controls on the left hand side. On the right hand side, you see a preview of the image encoded in your nonogram.

At the top of the left panel, you can adjust the grid size. Then you can pick between three options:

1. An empty image (all white).
2. A randomly generated image - you can adjust the black-to-white ratio and how correlated neighbouring pixels are.
3. Load an image file and convert it to a nonogram - you can adjust the brightness threshold of the black and white image.

When you are happy with the preview on the right and the uniqueness properties of you nonogram, you can press OK (or hit 'Enter') to load it into the Nonogram GUI.

Integrating other Nonogram Solvers into the GUI

We integrated four existing nonogram solvers into the UI to compare them to our solvers:

1. nonogrid (https://github.com/tsionyx/nonogrid)
2. pbnsolve (https://webpbn.com/pbnsolve.html)
3. copris-nonogram (https://cspsat.gitlab.io/copris-puzzles/nonogram/)
4. BGU solver (http://www.cs.bgu.ac.il/~benr/nonograms/)

These solvers can be found in the 'other_solvers' branch of this repository:

git checkout other_solvers

We do not claim ownership or authorship over any of these source files and have only copied them into the repository for convenience.

Most need to be compiled separately. See the extended readme on that branch for details on how to setup each solver.