pnmtopalm
Updated: 05 October 2003
Table Of Contents
NAME
pnmtopalm - convert a PNM image to a Palm pixmap
SYNOPSIS
pnmtopalm
[-verbose]
[-depth=N]
[-maxdepth=N]
[-colormap]
[-transparent=color]
[-offset]
[-rle-compression|-scanline-compression]
[pnmfile]
Minimum unique abbreviation of option is acceptable. You may use
double hypens 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
pnmtopalm reads a PNM image as input, from Standard Input or
pnmfile and produces a Palm pixmap as output.
Palm pixmap 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
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
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. Any depth greater than 1 will
produce a version 1 or 2 bitmap. Because the default Palm 8-bit
colormap is not grayscale, if the input is a grayscale or monochrome
pixmap, 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
-
Fill in the nextDepthOffset field in the file header, to
provide for multiple renditions of the pixmap in the same file.
- -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=color
-
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.
This also makes the output bitmap a version 2 bitmap. Transparency
works only on Palm OS 3.5 and higher.
- -rle-compression
-
Specifies that the output Palm bitmap will use the Palm RLE
compression scheme, and will be a version 2 bitmap. RLE compression
works only with Palm OS 3.5 and higher.
- -scanline-compression
-
Specifies that the output Palm bitmap will use the Palm scanline
compression scheme, and will be a version 2 bitmap. Scanline
compression works only in Palm OS 2.0 and higher.
SEE ALSO
palmtopnm,
pnmquant,
pnmremap,
pnm
NOTES
An additional compression format, packbits,
was added with PalmOS 4.0. This package should be updated to
be able to generate that.
Palm pixmaps may contains multiple renditions of the same pixmap,
in different depths. To construct an N-multiple-rendition Palm pixmap
with pnmtopalm, first construct renditions 1 through N-1 using
the -offset option, then construct the Nth pixmap without the
-offset option. Then concatenate the individual renditions
together in a single file using cat.
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.
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