Peter Selinger : Potrace
▻http://potrace.sourceforge.net
Potrace is a tool for tracing a #bitmap, which means, transforming a bitmap into a smooth, scalable image. The input is a bitmap (PBM, PGM, PPM, or BMP format), and the default output is an encapsulated PostScript file (EPS). A typical use is to create EPS files from scanned data, such as company or university logos, handwritten notes, etc. The resulting image is not “jaggy” like a bitmap, but smooth. It can then be rendered at any resolution. Potrace can currently produce the following output formats: EPS, PostScript, PDF, #svg (scalable #vector graphics), DXF, #geojson, PGM (for easy antialiasing of pixel-based #images), Gimppath, and XFig. Additional backends might be added in the future.
via ▻http://blog.thematicmapping.org/2015/12/mapping-real-time-snow-cover.html