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ppmtoilbm - convert a PPM image into an ILBM file |
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ppmtoilbm [-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] |
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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: |
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Normal ILBMs with 1-16 planes |
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Amiga HAM with 3-16 planes |
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24 bit |
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Color map (BMHD + CMAP chunk only, nPlanes = 0) |
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Unofficial direct color. 1-16 planes for each color component. |
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Chunks written: BMHD, CMAP, CAMG (only for HAM), BODY (not for colormap files) unofficial DCOL chunk for direct color ILBM. |
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Options marked with (*) can be prefixed with a ’no’, e.g. ’-nohamif’. All options can be abbreviated to their shortest unique prefix. |
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-maxplanes | -mp n |
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(default 5, minimum 1, maximum 16) Maximum planes to write in a normal ILBM. If the image 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. |
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-fixplanes | -fp b |
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(min 1, max 16) If a normal ILBM is written, it will have exactly <n> planes. |
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-hambits | -hamplanes n |
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(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. |
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-normal |
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Turns off -hamif/-24if/-dcif, -hamforce/-24force/-dcforce and -cmaponly. Also sets compression type to byterun1. This is the default. |
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-hamif (*) |
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-24if (*) |
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-dcif (*) |
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Write a HAM/24bit/direct color file if the image does not fit into <maxplanes> planes. |
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-hamforce (*) |
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-24force (*) |
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-dcforce (*) |
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Write a HAM/24bit/direct color file. |
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-dcbits r g b |
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-dcplanes r g b |
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(default 5, min 1, max 16). Select number of bits for red, green and blue in a direct color ILBM. |
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-ecs |
Shortcut for: -hamplanes 6 -maxplanes 5 |
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This is the default. |
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-aga |
Shortcut for: -hamplanes 8 -maxplanes 8 |
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-ham6 |
Shortcut for: -hamplanes 6 -hamforce |
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-ham8 |
Shortcut for: -hamplanes 8 -hamforce |
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-compress (*) |
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This is the default. 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. |
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-cmethod none|byterun1 |
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This option does the same thing as -compress. |
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-map ppmfile |
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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. |
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-cmaponly |
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Write a colormap file: only BMHD and CMAP chunks, no BODY chunk, nPlanes = 0. |
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-savemem |
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See the -compress option. |
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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. |
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Amiga ROM Kernel Reference Manual - Devices (3rd Ed.) Addison Wesley, ISBN 0-201-56775-X |
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ppm(1), ilbmtoppm(1) |
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Copyright (C) 1989 by Jef Poskanzer. Modified October 1993 by Ingo Wilken (Ingo.Wilken@informatik.uni-oldenburg.de) |