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 file as input and produces a PPM image if the
24       FITS file consists of 3 image planes (NAXIS = 3 and NAXIS3 = 3),  or  a
25       PGM  image  if the FITS file consists of 2 image planes (NAXIS = 2), or
26       if you specify the -image option.  The results may need to  be  flipped
27       top for bottom; if so, just pipe the output through pamflip -tb.
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29       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              <code>
76                  eval 'fitstopnm -printmax $filename |     awk {min = $1; max = $2}           END {print "min=" min; " max=" max}'
77              </code>
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REFERENCES

83       FITS  stands  for  Flexible Image Transport System.  A full description
84       can be found in Astronomy & Astrophysics Supplement Series  44  (1981),
85       page 363.
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SEE ALSO

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