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RLELDMAP(1) DragonFly General Commands Manual 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.
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).
-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
4th Berkeley Distribution November 12, 1986 RLELDMAP(1)