Manual: pamunlookup

Pamunlookup User Manual(1)			   General Commands Manual			  Pamunlookup User Manual(1)

NAME
       pamunlookup - inverse of pamlookup

SYNOPSIS
       pamunlookup -lookupfile=lookupfile inputfile

       All  options  can  be  abbreviated to their shortest unique prefix.  You may use two hyphens instead of one.  You may
       separate an option name and its value with white space instead of an equals sign.

DESCRIPTION
       This program is part of Netpbm(1).

       pamunlookup is best described as the inverse of pamlookup (without -byplane).  For example,  the	 following  normally
       yields output identical to the input:

	   $ cat input.ppm | \
	       pamunlookup -lookupfile=map.pam | \
	       pamlookup -lookupfile=map.pam \
	       > output.ppm

       Specifically,  pamunlookup  takes  an  input image and produces an output image of the same width and height in which
       each tuple is a single number.  That number is the index in a given lookup table of the tuple value that	 is  in	 the
       same position in the input image.

       You specify the lookup table the same way as for pamlookup .

       Where  a tuple in the input image is not in the lookup table, the number pamunlookup places in the output index image
       is one greater than the highest index in the lookup table.  Accordingly, the maxval of the output index image is	 the
       size of the lookup table.

   Example
       Here is an example of pamunlookup's function.

       Consider an input image consisting of a 3x2 PPM as follows:

       red     yellow	red
       beige   beige	beige

       and a lookup table consisting of a 3x1 PPM image as follows:

       red   yellow   beige

       The  lookup  table above says Index 0 corresponds to the color red, Index 1 corresponds to yellow, and Index 2 corre‐
       sponds to beige.	 The output of pamunlookup is the following index image:

       0   1   0
       2   2   2

   Miscellaneous
       The inputfile argument identifies the file containing the index PAM or PNM image.  - means Standard Input.  It  won't
       work if both the input image file and lookup table file are Standard Input.

       The output index image goes to Standard Output.

OPTIONS
       In addition to the options common to all programs based on libnetpbm (most notably -quiet, see  Common Options ), pa‐
       munlookup recognizes the following command line option:

       -lookupfile=lookupfile
	      lookupfile  names the file that contains the PAM or PNM image that is the lookup table.  This option is manda‐
	      tory.

SEE ALSO
       pamlookup(1), ppmchange(1), pnmcolormap(1), pnm(1), pam(1)

HISTORY
       pamunlookup was new in Netpbm 10.72 (September 2015).

DOCUMENT SOURCE
       This manual page was generated by the Netpbm tool 'makeman' from HTML source.  The master documentation is at

	      http://netpbm.sourceforge.net/doc/pamunlookup.html

netpbm documentation				       09 August 2015				  Pamunlookup User Manual(1)