NAME¶
ppmtoilbm - convert a portable pixmap into an ILBM file
SYNOPSIS¶
ppmtoilbm [
-maxplanes|
-mp N]
[
-fixplanes|
-fp N] [
-ham6|
-ham8]
[
-dcbits|
-dcplanesr
gb
]
[
-normal|
-hamif|
-hamforce|
-24if|
-24force|
-dcif
|-dcforce
|-cmaponly
] [
-ecs|
-aga]
[
-compress|
-nocompress] [
-cmethod type]
[
-mapppmfile
] [
-savemem] [
ppmfile]
DESCRIPTION¶
Reads a portable pixmap as input. Produces an ILBM file as output. Supported
ILBM types are:
- 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 pixmap 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 n
- (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 supports 6 and 8 planes, so for now
you should only use this values.
- -normal (default)
- Turns off -hamif/-24if/-dcif, -hamforce/-24force/-dcforce
and -cmaponly. Also sets compression type to byterun1.
- -hamif (*)
- -24if (*)
- -dcif (*)
- Write a HAM/24bit/direct color file if the pixmap does not
fit into <maxplanes> planes.
- -hamforce (*)
- -24force (*)
- -dcforce (*)
- Write a HAM/24bit/direct color file.
- -dcbits | -dcplanes r g b
- (default 5, min 1, max 16). Select number of bits for red,
green & blue in a direct color ILBM.
- -ecs (default)
- Shortcut for: -hamplanes 6 -maxplanes 5
- -aga
- Shortcut for: -hamplanes 8 -maxplanes 8
- -ham6
- Shortcut for: -hamplanes 6 -hamforce
- -ham8
- Shortcut for: -hamplanes 8 -hamforce
- -compress (*) (default)
- -cmethod none|byterun1
- 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.
- -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.
BUGS¶
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(5),
ilbmtoppm(1)
AUTHORS¶
Copyright (C) 1989 by Jef Poskanzer.
Modified October 1993 by Ingo Wilken (Ingo.Wilken@informatik.uni-oldenburg.de)