Monday, February 14, 2011

ppmtoilbm

ppmtoilbm(1)                                                      ppmtoilbm(1)



NAME
ppmtoilbm - convert a portable pixmap into an ILBM file

SYNOPSIS
ppmtoilbm [-maxplanes|-mp N] [-fixplanes|-fp N] [-ham6|-ham8]
[-dcbits|-dcplanesrgb] [-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 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 n
(min 1, max 16) If a normal ILBM is written, it will have
exactly 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 (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 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 mem‐
ory; 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 mem‐
ory requirements for compression at a minimum, but is very slow.

-map ppmfile
Write a normal ILBM using the colors in 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.

BUGS
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 ALSO
ppm(5), ilbmtoppm(1)

AUTHORS
Copyright (C) 1989 by Jef Poskanzer.
Modified October 1993 by Ingo Wilken (Ingo.Wilken@informatik.uni-olden‐
burg.de)




31 October 1993 ppmtoilbm(1)

No comments:

Post a Comment