Provided by: montage_4.0+dfsg-3_amd64 
NAME
mHistogram - None
SYNOPSIS
mHistogram [-d] -file in.fits minrange maxrange [logpower/gaussian/gaussian-log] -out out.hist
DESCRIPTION
The mViewer application makes PNG/JPEG files using FITS images as input. Part of that processing
involves analyzing the FITS files and creating a histogram that is used to inform the transformation from
pixel values to display colors/intensities. This processing is done inside mViewer itself.
However, there are situations where it helps to have the histogram earlier. For instance, you may have
several images to process into PNGs and wish to use the same histogram-based stretch for each one. Or
you may want to generate a set of pixel values that give the visual impression of a color bar (see mPad).
Sometimes, you may just want the histogram itself for display or analysis purposes.
The mHistogram module contains the same histogram code as mViewer but writes the results out to an ASCII
file which can then be read in by mHistogram, mPad or user programs.
OPTIONS
-d Turn on debugging.
-file in.fits minrange maxrange [logpower/gaussian/gaussian-log]
The FITS image file; stretch range; and (optionally) stretch mode. See the mViewer documentation
for more details.
-out out.hist
Output histogram (ASCII) file.
RESULT
If successful, the result is an ASCII file containing the histogram data, color table lookup mapping, and
some other information.
MESSAGES
ERROR Too few arguments following -file flag
ERROR Image file badfile invalid FITS
ERROR Can't find HDU badHDU
ERROR Too few arguments following -out flag
ERROR No input FITS file name given
ERROR No output histogram file name given
ERROR Cannot open output histogram file.
ERROR Grayscale/pseudocolor mode but no gray image given
ERROR FITS library error
ERROR leading numeric term in 'string' cannot be converted to a finite floating point number
ERROR is not a valid datatype
ERROR negative percentile
ERROR percentile context larger than 100
ERROR extra numeric term in context 'string' cannot be converted to a finite floating point number
ERROR context 'string' contains trailing junk
EXAMPLES
mHistogram -file SDSS_r.fits -2s max gaussian-log -out SDSS_r.hist
[struct stat="OK"]
BUGS
The drizzle algorithm has been implemented but has not been tested in this release.
If a header template contains carriage returns (i.e., created/modified on a Windows machine), the cfitsio
library will be unable to read it properly, resulting in the error: [struct stat="ERROR", status=207,
msg="illegal character in keyword"]
It is best for the background correction algorithms if the area described in the header template
completely encloses all of the input images in their entirety. If parts of input images are "chopped off"
by the header template, the background correction will be affected. We recommend you use an expanded
header for the reprojection and background modeling steps, returning to the originally desired header
size for the final coaddition. The default background matching assumes that there are no non-linear
background variations in the individual images (and therefore in the overlap differences). If there is
any uncertainty in this regard, it is safer to turn on the "level only" background matching (the "-l"
flag in mBgModel.
COPYRIGHT
2001-2015 California Institute of Technology, Pasadena, California
If your research uses Montage, please include the following acknowledgement: "This research made use of
Montage. It is funded by the National Science Foundation under Grant Number ACI-1440620, and was
previously funded by the National Aeronautics and Space Administration's Earth Science Technology Office,
Computation Technologies Project, under Cooperative Agreement Number NCC5-626 between NASA and the
California Institute of Technology."
The Montage distribution includes an adaptation of the MOPEX algorithm developed at the Spitzer Science
Center.