ppmtoilbm



Ppmtoilbm User Manual(0)                              Ppmtoilbm User Manual(0)




NAME

       ppmtoilbm - convert a PPM image 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]

       [-map ppmfile]

       [-savemem]

       [ppmfile]



DESCRIPTION

       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:




       ·      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 <n>  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 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  pic-
              ture.   The  current  Amiga hardware supports 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 | -dcplanes r g b
              (default 5, min 1, max 16).  Select  number  of  bits  for  red,
              green & 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 com-
              pression 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 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.






LIMITATIONS

       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(1), ilbmtoppm(1)



AUTHORS

       Copyright (C) 1989 by Jef Poskanzer.

       Modified October 1993 by Ingo Wilken (Ingo.Wilken@informatik.uni-olden-
       burg.de)



netpbm documentation            31 October 1993       Ppmtoilbm User Manual(0)

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