/depixel

Depixeling tool, based on "Depixelizing Pixel Art".

Primary LanguagePythonMIT LicenseMIT

This is an implementation of the "Depixelizing Pixel Art" algorithm:

  http://research.microsoft.com/en-us/um/people/kopf/pixelart/

This code is provided under the MIT license, the full text of which is in the
LICENSE file. As far as I know, the algorithm is not covered by any patents or
restrictive copyright.

This is very much a work in progress at present. My primary aim is to build a
tool to generate outline fonts from low-resolution bitmap fonts, but that isn't
ready yet.

So far I have the basic pixel grid deformation, shape outline extraction and
very simple curve smoothing (polygon -> closed quadratic B-spline -> Bezier
spline) implemented and I can write representations of the intermediate steps
to PNG and SVG. (The curve smoothing currently only works for closed shapes,
because I've been testing with simple monochrome images.)

There is a handy script to depixel PNGs in the `depixel/scripts` directory, and
there are unit tests covering some of the code.

I like to keep dependencies small and light, but there are some useful bits
I've pulled in (or will pull in) to make life easier:

 * I use `networkx` to do the graph stuff, because implementing it myself was
   getting messy. At some point I may write a streamlined graph implementation
   to include here and drop the dependency, but that's fairly low down my
   priority list at present.

 * I use `pypng` to do the PNG reading and writing, but that's isolated in the
   things that need it and the actual depixeling code works fine without it.

 * I use `svgwrite` to do the SVG writing, but that's isolated in the things
   that need it and the actual depixeling code works fine without it.

 * I'm probably going to need `bdflib` once I start working with fonts. Like
   the PNG stuff, I'll restrict its use to the places that need it. Since BDF
   is a fairly simple format and this library doesn't play nice with pip, I may
   rewrite the bits I need here as well.

 * I use Twisted's trial testrunner to run the tests, but that isn't required
   as long as you're happy to figure out how to discover and run the test cases
   yourself. (I think nose or something should work as well. I just like
   Twisted, and I had some editor hooks set up to use trial for other
   projects.)