ACfax - amateur FAX receiving software for Linux / X11
        Andreas Czechanowski, DL4SDC
        andreas.czechanowski@ins.uni-stuttgart.de

Features (or whatever you call it):
  AM or FM demodulation possible, adjustable filter width (3 levels),
  FM deviation adjustable for contrast adjustment. Uses the
  system processor for signal processing (filtering, demodulation).

  Grayscale reception with 64 gray levels

  Most parameters (except the modem settings) can subsequentially
  be adjusted (while or after the image is recieved), because the
  demodulated raw data stream is kept in memory.

  Image Polarity switch (pos/neg), Phasing polarity switch (pos/neg)

  APT tone detection for automatic start/stop (both frequencies
  adjustable), automatic phase-in (starts a new image)

  Variable IOC for height/width adjustment, variable LPM

  Writing direction horizontal/vertical up/down left/right switchable

  subsequent image centering and LPM fine correction possible

  automatic saving of received images as simple pgm-file