pamseq - generate PAM image of all possible tuple values, in sequence
SYNOPSIS
pamseq
[-tupletype=tupletype]
depthmaxval
All options can be abbreviated to their shortest unique prefix. You
may use two hyphens instead of one to designate an option. You may
use either white space or an equals sign between an option name and its
value.
pamseq generates a PAM image of a specified depth and specified
maxval that consists of a single row. The row consists of one tuple of
every possible value, in order.
For a depth of one, the order is simple: From 0 to maxval, going from
left to right. For higher depths, the highest numbered plane goes from
0 to maxval (going left to right) while all the other planes have value 0.
Then the sequence repeats except with the next highest plane set to a value
of 1, then 2, etc.
OPTIONS
-tupletype
This is the value of the "tuple_type" attribute of the created PAM image.
It can be any string up to 255 characters.
USAGE
To create a simple ramp of the values 0..255, for input to various matrix
calculations, try
<(>CW
pamseq 1 255
(>
(Before pamseq existed, pgmramp was often pressed into service
for this).
To create a PPM color map of all the possible colors representable with a
maxval of 5, do
<(>CW
pamseq 3 5 -tupletype=RGB | pamtopnm
(>
Again, with a modern program based on the Netpbm library, you don't need
the pamtopnm because a PAM RGB image is equivalent to a PPM image.
You can use such a color map with
pnmremap(1) to quantize the colors in an image. With the maxval of 5 given in the example, you get a color map
of the set of "web safe" colors as defined by Netscape. Most web
browsers guarantee that they can produce at least these 216 colors
(215 plus black).