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 composition 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
subscripted, the output value is equal
to the subscript 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 composition 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.
9
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,
factor*(n/(length-1))).
Factor defaults to 1.0 if not specified.
Negative values of factor will generate
a map with values equal to
range * max(0.0, 1.0 -
factor*(n/(length-1))).
-g gamma
Generate an applied map to compensate
for a display 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 particular 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 values)
blue0 blue1 blue2 ... (length
values)
As above, line breaks are irrelevant.
a separate 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 specified. Otherwise, the input will
be read from stdin.
SEE ALSO
applymap(1), urt(1), RLE(5).
AUTHOR
Spencer W. Thomas, University of Utah
9
- 4 Formatted: July 31, 1996