Provided by: netpbm_11.10.02-1build1_amd64 
NAME
pnmtopalm - convert a PNM image to a Palm Bitmap
SYNOPSIS
pnmtopalm
[-verbose]
[-depth=N]
[-maxdepth=N]
[-colormap]
[-transparent=colorspec]
[-density=N]
[-offset]
[-withdummy] [-scanline_compression | -rle_compression | -packbits_compression]
[pnmfile]
Minimum unique abbreviation of option is acceptable. You may use double 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.
DESCRIPTION
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 with 1, 2, or 4 bits per pixel, or mapped color files with 8
bit per pixel, or a direct color file with 16 bits per pixel, and pnmtopalm chooses this color depth
based on the maxval and number of colors in the input, unless you specify a depth (bits per pixel) with
-depth. You can also specify a maximum depth with -maxdepth to partially constrain pnmtopalm's choice.
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 palmgray2.map (4 shades of gray for a depth of 2), palmgray4.map (16 shades of gray for a depth of
4), and palmcolor8.map (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 directory with a netpbm-config
--datadir shell command.
Example:
pnmremap myimage.ppm \
-mapfile=$(netpbm-config --datadir)/palmgray2.map \
| pnmtopalm -depth=2 >myimage.palm
Compressed Palm Bitmap files, at least the ones pnmtopalm knows how to create, cannot have more than 8
bits per pixel. pnmtopalm defaults to 8 bits per pixel if you specify a compressed output. You can
specify the number of bits per pixel explicitly with -depth. -maxdepth has the same effect as -depth.
If you specify more than 8 bits per pixel with either of these, pnmtopalm fails.
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 compression, the version is at least 2.
• If you specify a custom colormap (-colormap option), the version 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 specify 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.
OPTIONS
In addition to the options common to all programs based on libnetpbm (most notably -quiet, see Common
Options ), pnmtopalm recognizes the following command line options:
-verbose
Display the format of the output file.
-depth=N
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 compatible with the various PalmOS 3.x versions
used in the Handspring Visor, so these images may also work in that device.
-maxdepth=N
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.
-offset
Set the nextDepthOffset field in the palm file header to indicate the end of the file (and pad the
end of the file to 4 bytes, since nextDepthOffset can point only to 4 byte boundaries).
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 "none."
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.
-withdummy
This option tells pnmtopalm to put in the stream, 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 interpreter like an invalid image header, so such an interpreter will stop
reading the stream there. But a new Palm Bitmap interpreter 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).
-colormap
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.
-transparent=colorspec
Marks one particular color as fully transparent.
colorspec is as described for the argument of the pnm_parsecolor() library routine .
Transparency works only on Palm OS 3.5 and higher.
-scanline_compression
Specifies that the output Palm bitmap will use the Palm scanline compression scheme. Scanline
compression works only in Palm OS 2.0 and higher.
-rle_compression
Specifies that the output Palm bitmap will use the Palm RLE compression scheme. RLE compression
works only with Palm OS 3.5 and higher.
-packbits_compression
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).
-density=N
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.
SEE ALSO
palmtopnm(1), pdbimgtopam(1), pnmquant(1), pnmremap(1), pnm(1)
NOTES
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 single 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.
If you specify the Palm packbits compression scheme for a 16-bit direct color bitmap, this program
generates an invalid bitmap.
AUTHORS
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.
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/pnmtopalm.html
netpbm documentation 25 August 2017 Pnmtopalm User Manual(1)