Syntax:  biw  (input FITS file)  (output FITS file)
           [-select]  [-mask]  [-esi]  [maskfile=]
           [-bias]
  
      Baseline-Interpolate-Window an image.
      Also "fixes" Keck header cards.
 Options:
    -select    : Select a new mask file.
    maskfile=  : Use this maskfile.
     -mask     : Mask bad columns, instead of interpolating.
     -esi      : Mask bad columns then ESI interpolate.
    -bias      : Lookup and subtract bias after BIW.