Ppmtoilbm User Manual(0) Ppmtoilbm User Manual(0)NAMEppmtoilbm - convert a PPM image into an ILBM file
SYNOPSISppmtoilbm
[-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]
[-savemem]
[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
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, ppm‐
toilbm 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 pic‐
ture. The current Amiga hardware supports 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 com‐
pression 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 col‐
ormap. 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 selec‐
tion 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 ALSOppm(1), ilbmtoppm(1)AUTHORS
Copyright (C) 1989 by Jef Poskanzer.
Modified October 1993 by Ingo Wilken (Ingo.Wilken@informatik.uni-olden‐
burg.de)
netpbm documentation 31 October 1993 Ppmtoilbm User Manual(0)
