rasttopnm(1) - Man pages

Rasttopnm User Manual(1) General Commands Manual Rasttopnm User Manual(1)

NAME
rasttopnm - convert a Sun rasterfile to a PNM image

SYNOPSIS
rasttopnm

[-index]

[rastfile]

DESCRIPTION
This program is part of Netpbm(1).

rasttopnm reads a Sun rasterfile as input and produces a PNM image as
output. The type of the output file depends on the input file - if it's
black and white, rasttopnm writes a PBM image. If it's grayscale, rast-
topnm writes a PGM. If it's color, rasttopnm writes a PPM. The program
tells you which type it is generating.

OPTIONS
In addition to the options common to all programs based on libnetpbm
(most notably -quiet, see ]8;;index.html#commonoptions\ Common Options]8;;\ ), rasttopnm recognizes the
following command line option:

-index This odd option tells rasttopnm to use the color map indices in
the raster as if they are the color values.

In a colormapped Sun rasterfile, the header of the file contains
a color map, associating each unique color that occurs in the
file with an index number. The raster portion of the file then
represents the color of a pixel with one of those colormap in-
dices.

This option has found use as follows: take a regular grayscale
Sun rasterfile in which all the grayscale value are represented,
so the colormap indices are identical to the color values. Mod-
ify its color map so as to alter the colors in the image, in par-
ticular to equalize the colors. With that modified rasterfile as
input, rasttopnm without -index produces the modified image. But
with -index, it produces the original unmodified image.

This option was new in Netpbm 10.56 (September 2011).