Provided by: netpbm_10.0-15ubuntu2_amd64
ppmtoilbm - convert a portable pixmap into an ILBM file
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]
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 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.
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.
Amiga ROM Kernel Reference Manual - Devices (3rd Ed.) Addison Wesley, ISBN 0-201-56775-X
Copyright (C) 1989 by Jef Poskanzer. Modified October 1993 by Ingo Wilken (Ingo.Wilken@informatik.uni-oldenburg.de) 31 October 1993 ppmtoilbm(1)