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.