1Fitstopnm User Manual(0)                              Fitstopnm User Manual(0)
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NAME

6       fitstopnm - convert a FITS file into a PNM image
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SYNOPSIS

10       fitstopnm  [-image=N]  [-scanmax] [-printmax] [-min=f] [-max=f] [-omax‐
11       val=N [FITSfile]
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13       Minimum unique abbreviation of option is acceptable.  You may use  dou‐
14       ble  hyphens  instead  of single hyphen to denote options.  You may use
15       white space in place of the equals sign to separate an option name from
16       its value.
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DESCRIPTION

21       This program is part of Netpbm(1).
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23       fitstopnm  reads a FITS (Flexible Image Transport System) file as input
24       and produces a PPM image if the FITS file consists of  3  image  planes
25       (NAXIS = 3 and NAXIS3 = 3), or a PGM image if the FITS file consists of
26       2 image planes (NAXIS = 2), or if you specify the -image option.
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28       The program tells you what kind of PNM image it is writing.
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OPTIONS

33       -image=N
34              This is for FITS files with three axes.  The assumption is  that
35              the  third axis is for multiple images, and this option lets you
36              select which one you want.  -omaxval=N
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38              This is the maxval that the output PNM image is to have.
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40              By default, the maxval is the least possible to retain  all  the
41              precision  of the FITS input.  That means the difference between
42              the highest and lowest sample value in the input.  If the values
43              range  from  -5 to 100, for example, the default maxval would be
44              106 and each PNM sample value would correspond to one FITS  sam‐
45              ple value.
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47              For  a  FITS input with floating point sample values, the preci‐
48              sion is essentially unlimited, so this is not possible.  In that
49              case, the default maxval is simply 255.
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51              This  option  was new in Netpbm 10.39 (June 2007).  Before that,
52              the output maxval is always the default.
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55       -min=float
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57       -max=float
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59              You can use these options to override the min and max values  as
60              read from the FITS header or the image data if the header has no
61              DATAMIN and DATAMAX keywords.
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64       -scanmax
65              Use this option to force the program to scan the data even  when
66              the header has DATAMIN and DATAMAX.
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69       -printmax
70              With this option, the program just prints the min and max values
71              and quits without doing its normal job.
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73              This is for use in shell programs.  Example:
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75                  eval 'fitstopnm -printmax $filename | \
76                  awk {min = $1; max = $2} \
77                        END {print "min=" min; " max=" max}'
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NOTES

83   Pixel Order
84       You may need to pass the output of fitstopnm through  pamflip  -topbot‐
85       tom.  See pamtofits ⟨pamtofits.html#pixelorder⟩
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SEE ALSO

90       pamtofits(1), pamflip(1), pgm(1) FITS(1)
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AUTHOR

94       Copyright  (C)  1989  by  Jef  Poskanzer,  with modifications by Daniel
95       Briggs  (dbriggs@nrao.edu)  and  Alberto  Accomazzi   (alberto@cfa.har‐
96       vard.edu).
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100netpbm documentation              22 May 2007         Fitstopnm User Manual(0)