potrace is a utility 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), Xfig, Gimppath, and PGM (for easy antialiasing). Additional backends might be added in the future.
Homepage: http://potrace.sourceforge.net/