RLELDMAP(1) 1 (Nov 12, 1986) 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 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.
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RLELDMAP(1) 1 (Nov 12, 1986) RLELDMAP(1)
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, 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).
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RLELDMAP(1) 1 (Nov 12, 1986) RLELDMAP(1)-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.
-m files ...
Read the color map for each channel from 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
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