RLELDMAP(1)                                         RLELDMAP(1)





NAME
       rleldmap - Load a new color map into an RLE file

SYNOPSIS
       rleldmap  [ -{ab} ] [ -n nchan length ] [ -s bits ] [ -l
       [ factor ] ] [ -g gamma ] [ -{tf} file ] [ -m files  ...
       ] [ -r rlefile ] [ -o outfile ] [ infile ]

DESCRIPTION
       The  program  will  load  a  specified color map into an
       RLE(5) file.  The color map may be computed by  rleldmap
       or  loaded  from  a file in one of several formats.  The
       input is read from infile or stdin if no file is  given,
       and the result is written to outfile or stdout.

       The  following  terms are used in the description of the
       program and its options:

       input map:
              A color map already in the input RLE file.

       applied map:
              The color  map  specified  by  the  arguments  to
              rleldmap.   This  map  will be applied to or will
              replace the input map to produce the output  map.

       output map:
              Unless  -a  or  -b is specified, this is equal to
              the applied map.  Otherwise it will be the compo-
              sition of the input and applied maps.

       map composition:
              If  the  applied  map is composed after the input
              map,  then  the  output  map  will   be   applied
              map[input map].  Composing the applied map before
              the input map produces an  output  map  equal  to
              input  map[applied map].  The maps being composed
              must either have the same number of channels,  or
              one  of  them  must have only one channel.  If an
              entry in the map being used  as  a  subscript  is
              larger  than  the  length  of  the map being sub-
              scripted, the output value is equal to  the  sub-
              script  value.   The  output map will be the same
              length as the subscript map  and  will  have  the
              number of channels that is the larger of the two.
              If the input map is used as a subscript, it  will
              be  downshifted  the  correct  number  of bits to
              serve as a subscript for the applied  map  (since
              the  color map in an RLE(5) file is always stored
              left justified  in  16  bit  words).   This  also
              applies to the applied map if it is taken from an
              RLE(5) file (-r  option  below).   Note  that  if
              there  is no input map, that the result of compo-
              sition will be exactly the applied map.

       nchan: The number of separate lookup  tables  (channels)
              making up the color map.  This defaults to 3.

       length:
              The  number  of  entries  in  each channel of the
              color map.  The default is 256.

       bits:  The size of each color map entry  in  bits.   The
              default value is the log base 2 of the length.

       range: The  maximum value of a color map entry, equal to
              2**bits - 1.

OPTIONS
       -a     Compose the applied map after the input map.

       -b     Compose the applied map  before  the  input  map.
              Only one of -a or -b may be specified.

       -n nchan length
              Specify  the size of the applied map if it is not
              3x256.  The length should be a power of two,  and
              will be rounded up if necessary.  If applying the
              map nchan must be either 1 or equal to the number
              of  channels  in  the input map.  It may have any
              value if the input map has one channel or is  not
              present.

       -s bits
              Specify  the  size  in  bits  of  the  color  map
              entries.  I.e., only the top bits  bits  of  each
              color map entry will be set.

              Exactly one of the options -l, -g, -t, -f, -m, or
              -r, must be specified.

       -l factor
              Generate a linear applied map with the nth  entry
              equal to
                        range       *       min(1.0,       fac-
              tor*(n/(length-1))).
              Factor defaults to 1.0 if not  specified.   Nega-
              tive  values  of  factor will generate a map with
              values equal to
                        range   *   max(0.0,   1.0    -    fac-
              tor*(n/(length-1))).

       -g gamma
              Generate  an applied map to compensate for a dis-
              play with the given  gamma.   The  nth  entry  is
              equal to
                        range * (n/(length-1))**(1/gamma).

       -t file
              Read  color  map  entries  from a table in a text
              file.  The values for each channel of a  particu-
              lar  entry  follow each other in the file.  Thus,
              for an RGB color map, the file would look like:
                        red0 green0    blue0
                        red1 green1    blue1
                        ...  ...  ...
              Line breaks in the input file are irrelevant.

       -f file
              Reads the applied map from a text file, with  all
              the  entries  for  each  channel  following  each
              other.  Thus, the input file above  would  appear
              as
                        red0 red1 red2 ... (length values)
                        green0  green1  green2 ... (length val-
              ues)
                        blue0 blue1 blue2 ... (length values)
              As above, line breaks are irrelevant.

       -m files ...
              Read the color map for each channel from a  sepa-
              rate  file.   The  number of files specified must
              equal the number of channels in the applied  map.
              (Note:  the  list  of  files  must be followed by
              another flag argument or by the null flag  --  to
              separate it from the infile specification.

       -o outfile
              The output will be written to the file outfile if
              this option is specified.  Otherwise  the  output
              will go to stdout.

       infile The  input will be taken from this file if speci-
              fied.  Otherwise, the input  will  be  read  from
              stdin.

SEE ALSO
       applymap(1), urt(1), RLE(5).

AUTHOR
       Spencer W. Thomas, University of Utah



1                         Nov 12, 1986              RLELDMAP(1)
