NAME
ppmtoilbm - convert a portable pixmap into an ILBM file
SYNOPSIS
ppmtoilbm
[-maxplanes|-mp
R N ]
[-fixplanes|-fp
R N ]
[-ham6|-ham8]
[-dcbits|-dcplanesrgb]
[-normal|-hamif|-hamforce|-24if|-24force|
-dcif|-dcforce|-cmaponly]
[-ecs|-aga]
[-compress|-nocompress]
[-cmethod
R 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.
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.
-dcif (*)
Write a HAM/24bit/direct color file if the pixmap does not
fit into <maxplanes> planes.
-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
Shortcut for: -hamplanes 8 -maxplanes 8
Shortcut for: -hamplanes 6 -hamforce
-ham8
Shortcut for: -hamplanes 8 -hamforce
-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)
