convert-nonogram

convert-nonogram is a tool that converts images to nonograms. (Why don't we just use indexed PNGs as the standard interchange format for nonograms?) Currently, it only outputs the widely-used XML-based webpbn format, because pbnsolve and nonogrid both accept that format.

How to use it

I use convert-nonogram to evaluate the solvability of nonograms while editing them as an image. You can install it with cargo install convert-nonogram.

All images supported by the [image] crate are supported as input, but if you try to create JPEG nonograms, you're going to have a bad time.

With pbnsolve

This is what I do, since [pbnsolve] provides useful information about difficulty. You'll have to download and install it [from a tarball].

Then, to evaluate an image, do:

convert-nonogram examples/tea.png | pbnsolve -tu

(-t requests detailed difficulty output, and -u requires checking for uniqueness. You can add -b to suppress output of the solved grid, but it's useful when debugging a non-unique nonogram)

With nonogrid

nonogrid can provide a better and more comprehensive visual representation of ambiguities in non-unique nonograms.

Make sure to install nonogrid with cargo install --features=xml,web nonogrid to allow parsing the XML format (and to enable directly downloading nonograms from the web, because why not). Then, to evaluate an image, do:

convert-nonogram examples/tea.png | nonogrid

With the Olsak solver

The [Olsak solver] comes in a tarball and doesn't even have a makefile! (Just do gcc grid.c -o grid to build it.) It accepts a different input format.

convert-nonogram examples/tea.png --olsak | grid -