`-bitmask file`
  mask frame (see phcorr for description). Only pixels, marked by this mask are processed.
`-st, --saturate s`
  Set saturate limit in units of input frames. Any pixel out of the range th < pixel < s (see also --threshold) is rejected the processing. This switch is useful mainly for over-exposed parts of frames and elimination of non-linear parts of gradation curve. If unset, the value is determined from FITS header (by FITS_KEY_SATURATE, see). If the keyword is not found and the frame contains an integer number type, the maximum value 2**BITPIX-1 is provided, otherwise the maximum value of given data-type is used (which practically switch-off the saturation bound check). The value is set in ADU (values reported by camera).
`-th, --threshold th`
  Set threshold limit in units of input frames. Any pixel below the value is rejected from the processing. If unset, the value is number one. Threshold is minor significance parameter. It should help for faulty values or filtering of bad pixels. The value is set in ADU (values reported by camera).