POTRACE - transform bitmaps into vector graphics

 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), and the default output is one of several vector
 file formats.

 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.

 A separate program, mkbitmap, is also provided. This program can act
 as a pre-processor for Potrace, applying scaling and various filters
 to an image before converting it to a bitmap. This is useful for
 potracing greyscale and color images.