Input formats:  PNG, TGA, PBM, PNM, PGM, PPM and BMP
Output formats: eps, ai, p2e, sk, svg, fig, emf, mif, er, dxf, epd, pdf, cgm and
dr2d

Example usage:

To convert image.png to image.svg:
autotrace --output-format svg image.png >image.svg

For more info on options:
autotrace -h