Pnmtopalm User Manual(0)                              Pnmtopalm User Manual(0)


       pnmtopalm - convert a PNM image to a Palm Bitmap










       [-withdummy] [-scanline-compression | -rle-compression | -packbits-com-


       Minimum unique abbreviation of option is acceptable.  You may use  dou-
       ble  hyphens  instead  of single hyphen to denote options.  You may use
       white space in place of the equals sign to separate an option name from
       its value.


       This program is part of Netpbm(1).

       pnmtopalm  reads  a  PNM image as input, from Standard Input or pnmfile
       and produces a Palm Bitmap as output.

       Palm Bitmap files are either grayscale files 1, 2, or 4 bits  wide,  or
       color  files  8  bits wide, so pnmtopalm automatically scales colors to
       have an appropriate maxval, unless you specify a depth  or  max  depth.
       Input  files  must have an appropriate number and set of colors for the
       selected output constraints.

       This often means that you should run the PNM image through pnmquant  or
       pnmremap  before  you  pass it to pnmtopalm.  Netpbm comes with several
       colormap files you can use with pnmremap for this  purpose.   They  are  (4  shades  of gray for a depth of 2), (16
       shades of gray for a depth of 4), and  (232  colors  in
       default  Palm  colormap).  In a standard Netpbm installation, these are
       in the Netpbm data directory, and you can find the Netpbm  data  direc-
       tory with a netpbm-config --datadir shell command.


         pnmremap myimage.ppm            -mapfile=$(netpbm-config --datadir)/   | pnmtopalm -depth=2 >myimage.palm

   Palm Bitmap Version
       pnmtopalm  generates a Version 0, 1, 2, or 3 Palm Bitmap.  It generates
       the oldest (lowest) version it can for the given image and the  options
       you specify.

       ·      If  you  specify  a density (-density option) higher than ’low,’
              the version is at least 3.

       ·      If you specify transparency (-transparent option)  or  any  com-
              pression, the version is at least 2.

       ·      If you specify a custom colormap (-colormap option), the verison
              is at least 1.

       ·      If the image has more than one bit per pixel, the version is  at
              least 1.  The image has more than one bit per pixel if you spec-
              ify it with -depth or if you let it default and  the  image  has
              more than two colors (or shades of gray).

       All  releases  of Palm OS can read a Version 0 bitmap.  Palm OS 3.0 and
       later can read a Version 1 bitmap.  Palm OS 3.5 and later  can  read  a
       Version  2 bitmap.  To read a Version 3 bitmap, you need Palm OS Garnet
       or a handheld running the High Density Display Feature Set.


              Display the format of the output file.

              Produce a file of depth N, where N must be either 1, 2, 4, 8, or
              16.   Because  the default Palm 8-bit colormap is not grayscale,
              if the input is a grayscale or monochrome image, the output will
              never  be  more  than  4  bits deep, regardless of the specified
              depth.  Note that 8-bit color works  only  in  PalmOS  3.5  (and
              higher),  and  16-bit direct color works only in PalmOS 4.0 (and
              higher).  However, the 16-bit direct color format is  also  com-
              patible  with  the various PalmOS 3.x versions used in the Hand-
              spring Visor, so these images may also work in that device.

              Produce a file of minimal depth, but in any  case  less  than  N
              bits  wide.   If  you  specify 16-bit, the output will always be
              16-bit direct color.

              Set the nextDepthOffset field in the palm file header  to  indi-
              cate  the  end  of  the  file  (and pad the end of the file to 4
              bytes, since nextDepthOffset can point only  to  4  byte  bound-

              A  palm  image  file can contain multiple renditions of the same
              image, with different color depths, so a viewer can  choose  one
              appropriate  for  the  display.  The nextDepthOffset field tells
              where in the stream the next rendition begins.

              pnmtopalm creates a file that contains only one image,  but  you
              can  separately concatenate multiple one-image files to create a
              multi-image file.  If you do that, you’ll need to use -offset so
              that the resulting concatenation is a correct stream.

              By default (if you don’t specify -offset), pnmtopalm generates a
              nextDepthOffset field that says there is no following image (and
              does not add any padding after the image).

              Version  3  Palm  Bitmaps actually have a nextBitmapOffset field
              instead  of  the  nextDepthOffset.   The  foregoing  applies  to
              whichever is relevant.

              The  -offset  option  was  new  in  Netpbm 10.26 (January 2005).
              Before that, pnmtopalm always set the nextDepthOffset  field  to

              Before  Netpbm 10.27 (March 2005), you cannot use -offset if you
              create a compressed raster (because pnmtopalm isn’t smart enough
              to  be  able to know the size of the image at the time it writes
              the header).  You also cannot use it with 16 bit color depth  or
              with the -colormap option, for much the same reason.

              This  option  tells  pnmtopalm to put in the stream, after after
              the image, a dummy image header  to  introduce  subsequent  high
              density images.

              This  dummy image header is a special sequence specified in Palm
              Bitmap specifications.  It looks to an older Palm Bitmap  inter-
              preter  like an invalid image header, so such an intepreter will
              stop reading the stream there.  But a  new  Palm  Bitmap  inter-
              preter  recognizes it for what it is (just something to choke an
              old interpreter) and skips over it.  Presumably, you will add to
              the stream after this high density images which would confuse an
              older interpreter.

              If you specify -withdummy, you must also specify -offset,  since
              it doesn’t make any sense otherwise.

              -withdummy was new in Netpbm 10.27 (March 2005).

              Build a custom colormap and include it in the output file.  This
              is not recommended by Palm, for efficiency reasons.   Otherwise,
              pnmtopalm uses the default Palm colormap for color output.

              Marks  one particular color as fully transparent.  The format to
              specify  the  color  is  either  (when   for   example   orange)
              ’1.0,0.5,0.0’, where the values are floats between zero and one,
              or with the syntax ’#RGB’, ’#RRGGBB’ or ’#RRRRGGGGBBBB’ where R,
              G  and  B  are  hexadecimal numbers.  Transparency works only on
              Palm OS 3.5 and higher.

              Specifies that the output Palm bitmap will use the Palm scanline
              compression  scheme.  Scanline compression works only in Palm OS
              2.0 and higher.

              Specifies that the output Palm bitmap will use the Palm RLE com-
              pression  scheme.   RLE  compression works only with Palm OS 3.5
              and higher.

              Specifies that the output Palm bitmap will use the Palm packbits
              compression  scheme.   Packbits compression works only with Palm
              OS 4.0 and higher.

              This option was new in Netpbm 10.27 (March 2005).

              This specifies the Palm Bitmap density.  The density is a number
              that  is  proportional  to  the resolution the image should have
              when displayed.  The proportionality factor is up to whatever is
              doing the displaying, but it’s helpful to think of these numbers
              as being pixels per inch.  The allowable values are:

       ·      72

       ·      108

       ·      144

       ·      216

       ·      288

              This option was new  in  Netpbm  10.27  (March  2005).   Earlier
              Netpbm  could  not generate Version 3 Palm Bitmaps, so there was
              no such thing as density.


       palmtopnm(1), pnmquant(1), pnmremap(1), pnm(1), PalmOS  Reference  (1),
       PalmOS Companion .


       Palm  Bitmaps  may  contains multiple renditions of the same bitmap, in
       different depths.  To construct  an  N-multiple-rendition  Palm  Bitmap
       with  pnmtopalm,  first  construct  renditions  1 through N-1 using the
       -offset option, then  construct  the  Nth  image  without  the  -offset
       option.   Then concatenate the individual renditions together in a sin-
       gle file using cat.

       If you will include both high density and low density  renditions,  put
       the  high  density  images last and when you create the last of the low
       density images, use the -withdummy option.

       You cannot generate an alpha mask if the Palm pixmap has a  transparent
       color.   However, you can still do this with ppmcolormask with a Netpbm
       pipe similar to:

       palmtopnm   pixmap.palm   |   ppmcolormask   palmtopnm    -transparent


       This program was originally written as ppmtoTbmp.c, by Ian Goldberg and
       George Caswell.  It was completely re-written by Bill  Janssen  to  add
       color,  compression, and transparency function.  Copyright 1995-2001 by
       Ian Goldberg, George Caswell, and Bill Janssen.

netpbm documentation            05 October 2003       Pnmtopalm User Manual(0)

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