From fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4 Mon Sep 17 00:00:00 2001
From: Joseph Hunkeler <jhunkeler@gmail.com>
Date: Wed, 8 Jul 2015 20:46:52 -0400
Subject: Initial commit

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 noao/imred/bias/doc/colbias.hlp | 113 ++++++++++++++++++++++++++++++++++++++++
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 create mode 100644 noao/imred/bias/doc/colbias.hlp

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+.help colbias Mar93 noao.imred.bias
+.ih
+NAME
+colbias -- Fit and subtract an average column bias
+.ih
+USAGE	
+.nf
+colbias input output
+.fi
+.ih
+PARAMETERS
+.ls input
+Images to be bias subtracted.  The images may not contain image sections.
+.le
+.ls output
+Output bias subtracted images.  An output images may be the same as its
+matching input image.  The output pixel type will be real regardless
+of the input pixel type.
+.le
+.ls bias = "[]"
+Bias section appended to the input image to define the bias region.
+The default section or an empty string will use the full image.
+.le
+.ls trim = "[]"
+Trim section appended to the input image to define the region to be
+bias subtracted and output.  The default section or an empty string
+will use the full image.
+.le
+.ls median = no
+Take the median of the bias columns?  If no then the bias
+columns are averaged.
+.le
+.ls function = "spline3"
+The function fit to the average bias line.  The functions are "legendre",
+"chebyshev", "spline1", or "spline3".  Abbreviations are allowed.
+.le
+.ls order
+The order (number of terms or number of spline pieces) in the function.
+.le
+.ls low_reject = 3.0
+The low sigma rejection factor.
+.le
+.ls high_reject = 3.0
+The high sigma rejection factor.
+.le
+.ls niterate = 1
+The maximum number of rejection iterations.
+.le
+.ls interactive = yes
+Fit the average bias line interactively?
+.le
+.ls logfiles = ""
+List of log files.  If no file name is given then no log file is kept.
+.le
+.ls graphics = "stdgraph"
+Graphics output device for interactive graphics.
+.le
+.ls cursor = ""
+Graphics cursor input
+.le
+.ih
+DESCRIPTION
+For each input image in the input image list an average or median bias
+column is determined from the bias region.  The bias region is defined by
+the bias section applied to the input image.  A function of the image lines
+is fit to the average bias column.  This function is subtracted from each
+image column in the trim region.  The trim region is defined by the trim
+section applied to the input image.  The bias subtracted and trimmed image
+is output to the output image.  The input and output images may not contain
+sections and the number of images in each list must be the same.
+
+If the interactive flag is set then the user may interactively examine
+and fit the average bias column.  The interactive fitting is done using the
+interactive curve fitting routine (see icfit).  Before each image is
+processed a prompt of the form "colbias image (yes)? " is given.
+A response of yes allows interactive fitting for the specified image
+while a response of no uses the last defined fitting parameters.
+The default value is accepted with a carriage return.  The possible
+responses are "yes", "no", "YES", or "NO".  The capitalized responses
+permanently set the response to yes or no and the prompt is not
+issued again for the remaining images.  Thus, a response of NO processes
+the remaining images non-interactively while a response of YES processes
+the remaining image interactively without prompting.
+.ih
+EXAMPLES
+The bias region for a set of images occupies columns 801 to 832 and lines
+1 to 800.  To subtract the bias and remove the bias region:
+
+.nf
+	cl> colbias.bias = "[801:832,*]"
+	cl> colbias.trim = "[1:800,*]"
+	cl> colbias ccd* ccd*
+	colbias ccd001 (yes)? yes
+	colbias ccd002 (yes)?
+	colbias ccd003 (no)? NO
+.fi
+
+The first two lines set the bias and trim parameters.  These parameters
+could be temporarily set on the command line but generally these parameters
+are only changed when new instruments are used.  The first image
+is interactively fit and the fitting order is change to 2.  The
+second image is examined and the fit found to be acceptable.  All remaining
+image are then fit non-interactively using the same fitting parameters.
+.ih
+REVISIONS
+.ls COLBIAS V2.10.3
+The output pixel type is now real instead of preserving the pixel type
+of the input image.
+.le
+.ih
+SEE ALSO
+icfit
+.endhelp
-- 
cgit 

