ppmtoilbm1

Usage

Overview

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:

Chunks written: BMHD, CMAP, CAMG (only for HAM), BODY (not for colormap files) unofficial DCOL chunk for direct color ILBM.

Options

In addition to the options common to all programs based on libnetpbm (most notably -quiet, see
Common Options ⟨index.html#commonoptions⟩ ), ppmtoilbm recognizes the following command line 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 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.

-fixplanes | -fp b

(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 understands 6 and 8 planes, so for now you should only use this values.

-normal

Turns off -hamif/-24if/-dcif, -hamforce/-24force/-dcforce and -cmaponly. Also sets compression type to byterun1.

This is the default.

-hamif (*)

-24if (*)

-dcif (*)

Write a HAM/24bit/direct color file if the image does not fit into <maxplanes> planes.

-hamforce (*)

-24force (*)

-dcforce (*)

Write a HAM/24bit/direct color file.

-dcbits r g b

-dcplanes r g b

(default 5, min 1, max 16). Select number of bits for red, green and blue in a direct color ILBM.

-ecs

Shortcut for: -hamplanes 6 -maxplanes 5

This is the default.

-aga

Shortcut for: -hamplanes 8 -maxplanes 8

-ham6

Shortcut for: -hamplanes 6 -hamforce

-ham8

Shortcut for: -hamplanes 8 -hamforce

-compress (*)

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.

-cmethod none|byterun1

This option does the same thing as -compress.

-map ppmfile

Write a normal ILBM using the colors in <ppmfile> as the colormap. The colormap file also determines the number of planes; -maxplanes and -fixplanes are ignored.

-cmaponly

Write a colormap file: only BMHD and CMAP chunks, no BODY chunk, nPlanes = 0.

-savemem

See the -compress option.

Limitations

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

Document source

This manual page was generated by the Netpbm tool 'makeman' from HTML source. The master documentation is at

http://netpbm.sourceforge.net/doc/ppmtoilbm.html