deletions | additions       diff --git a/preprocessing.tex b/preprocessing.tex  index f7e553f..4bc86fa 100644  --- a/preprocessing.tex  +++ b/preprocessing.tex 
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The debias and gain stage removes a bias frame (if available), subtracts off the overscan region, and multiplies each frame by the gain.  \subsubsection{Input}  Given an observation file \verb|ifuyyyymmdd_hhmmss.fits| and a \verb|bias.fits| file, this code will subtract off the bias frame, and then remove the overscan. The code also sets the units of the frame to $e^-$ ($ADU ($e^-=ADU  \times GAIN$). \subsection{Output}  \verb|b_ifuyyyymmdd_hhmmss.fits| which has been debiased and degained.