1Pamunlookup User Manual(0)                          Pamunlookup User Manual(0)
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NAME

6       pamunlookup - inverse of pamlookup
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SYNOPSIS

10       pamunlookup -lookupfile=lookupfile inputfile
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12       All  options  can  be abbreviated to their shortest unique prefix.  You
13       may use two hyphens instead of one.  You may separate  an  option  name
14       and its value with white space instead of an equals sign.
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DESCRIPTION

18       This program is part of Netpbm(1).
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20       pamunlookup is best described as the inverse of pamlookup (without -by‐
21       plane).  For example, the following normally yields output identical to
22       the input:
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24           $ cat input.ppm | \
25               pamunlookup -lookupfile=map.pam | \
26               pamlookup -lookupfile=map.pam \
27               > output.ppm
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30       Specifically,  pamunlookup  takes an input image and produces an output
31       image of the same width and height in which each tuple is a single num‐
32       ber.   That  number  is  the index in a given lookup table of the tuple
33       value that is in the same position in the input image.
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35       You  specify  the  lookup  table  the  same  way   as   for   pamlookup
36       ⟨pamlookup.html#lookupimage⟩ .
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38       Where a tuple in the input image is not in the lookup table, the number
39       pamunlookup places in the output index image is one  greater  than  the
40       highest index in the lookup table.  Accordingly, the maxval of the out‐
41       put index image is the size of the lookup table.
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45   Example
46       Here is an example of pamunlookup's function.
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48       Consider an input image consisting of a 3x2 PPM as follows:
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51       red     yellow   red
52       beige   beige    beige
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54       and a lookup table consisting of a 3x1 PPM image as follows:
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57       red   yellow   beige
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59       The lookup table above says Index 0 corresponds to the color red, Index
60       1  corresponds to yellow, and Index 2 corresponds to beige.  The output
61       of pamunlookup is the following index image:
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64       0   1   0
65       2   2   2
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68   Miscellaneous
69       The inputfile argument identifies the file containing the index PAM  or
70       PNM  image.   -  means Standard Input.  It won't work if both the input
71       image file and lookup table file are Standard Input.
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73       The output index image goes to Standard Output.
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OPTIONS

78       In addition to the options common to all programs  based  on  libnetpbm
79       (most notably -quiet, see
80        Common  Options  ⟨index.html#commonoptions⟩  ), pamunlookup recognizes
81       the following command line option:
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85       -lookupfile=lookupfile
86              lookupfile names the file that contains the  PAM  or  PNM  image
87              that is the lookup table.  This option is mandatory.
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SEE ALSO

94       pamlookup(1), ppmchange(1), pnmcolormap(1), pnm(1), pam(1)
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HISTORY

99       pamunlookup was new in Netpbm 10.72 (September 2015).
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DOCUMENT SOURCE

102       This  manual  page was generated by the Netpbm tool 'makeman' from HTML
103       source.  The master documentation is at
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105              http://netpbm.sourceforge.net/doc/pamunlookup.html
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107netpbm documentation            09 August 2015      Pamunlookup User Manual(0)
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