Ppmtoilbm User Manual
Section: Misc. Reference Manual Pages (0)
Updated: 28 June 2015
Page Index
NAME
ppmtoilbm - convert a PPM image into an ILBM file
SYNOPSIS
ppmtoilbm
[-maxplanes|-mp N]
[-fixplanes|-fp N]
[-ham6|-ham8]
[{-dcbits|-dcplanes} r g b]
[
-normal|-hamif|-hamforce|-24if|-24force|
-dcif|-dcforce|-cmaponly
]
[-ecs|-aga]
[-compress|-nocompress]
[-cmethod type]
[-map ppmfile]
[ppmfile]
DESCRIPTION
This program is part of
Netpbm(1).
ppmtoilbm reads a PPM image as input. Produces an ILBM file
as output. ppmtoilbm understands the following ILBM types:
- •
-
Normal ILBMs with 1-16 planes
- •
-
Amiga HAM with 3-16 planes
- •
-
24 bit
- •
-
Color map (BMHD + CMAP chunk only, nPlanes = 0)
- •
-
Unofficial direct color. 1-16 planes for each color component.
Chunks written: BMHD, CMAP, CAMG (only for HAM), BODY (not for
colormap files) unofficial DCOL chunk for direct color ILBM.
OPTIONS
In addition to the options common to all programs based on libnetpbm
(most notably -quiet, see
Common Options
), ppmtoilbm recognizes the following
command line options:
Options marked with (*) can be prefixed with a "no",
e.g. "-nohamif". All options can be abbreviated to their
shortest unique prefix.
- -maxplanes | -mp n
-
(default 5, minimum 1, maximum 16) Maximum planes to write in a
normal ILBM. If the image does not fit into <n> planes,
ppmtoilbm writes a HAM file (if -hamif is used), a 24bit file (if
-24if is used) or a direct color file (if -dcif is used) or aborts
with an error.
- -fixplanes | -fp b
-
(min 1, max 16) If a normal ILBM is written, it will have exactly
<n> planes.
- -hambits | -hamplanes n
-
(default 6, min 3, max 16) Select number of planes for HAM
picture. The current Amiga hardware understands 6 and 8 planes, so for
now you should only use this values.
- -normal
-
Turns off -hamif/-24if/-dcif, -hamforce/-24force/-dcforce and
-cmaponly. Also sets compression type to byterun1.
This is the default.
- -hamif (*)
-
- -24if (*)
-
- -dcif (*)
-
Write a HAM/24bit/direct color file if the image does not fit into
<maxplanes> planes.
- -hamforce (*)
-
- -24force (*)
-
- -dcforce (*)
-
Write a HAM/24bit/direct color file.
- -dcbits r g b
-
- -dcplanes r g b
-
(default 5, min 1, max 16). Select number of bits for red, green
and blue in a direct color ILBM.
- -ecs
-
Shortcut for: -hamplanes 6 -maxplanes 5
This is the default.
- -aga
-
Shortcut for: -hamplanes 8 -maxplanes 8
- -ham6
-
Shortcut for: -hamplanes 6 -hamforce
- -ham8
-
Shortcut for: -hamplanes 8 -hamforce
- -compress (*)
-
This is the default.
Compress the BODY chunk. The default compression method is
byterun1. Compression requires building the ILBM image in memory;
turning compression off allows stream-writing of the image, but the
resulting file will usually be 30% to 50% larger. Another alternative
is the -savemem option, this will keep memory requirements for
compression at a minimum, but is very slow.
- -cmethod none|byterun1
-
This option does the same thing as -compress.
- -map ppmfile
-
Write a normal ILBM using the colors in <ppmfile> as the
colormap. The colormap file also determines the number of planes, a
-maxplanes or -fixplanes option is ignored.
- -cmaponly
-
Write a colormap file: only BMHD and CMAP chunks, no BODY chunk,
nPlanes = 0.
- -savemem
-
See the -compress option.
LIMITATIONS
HAM pictures will always get a grayscale colormap; a real color
selection algorithm might give better results. On the other hand,
this allows row-by-row operation on HAM images, and all HAM images of
the same depth (no. of planes) share a common colormap, which is
useful for building HAM animations.
REFERENCES
Amiga ROM Kernel Reference Manual - Devices (3rd Ed.)
Addison Wesley, ISBN 0-201-56775-X
SEE ALSO
ppm(1),
ilbmtoppm(1)
HISTORY
For about a year in 1993-1994, there was a -savemem option.
AUTHORS
Copyright (C) 1989 by Jef Poskanzer.
Modified October 1993 by Ingo Wilken (Ingo.Wilken@informatik.uni-oldenburg.de)
DOCUMENT SOURCE
This manual page was generated by the Netpbm tool 'makeman' from HTML
source. The master documentation is at
-
http://netpbm.sourceforge.net/doc/ppmtoilbm.html