pnmtopalm - convert a portable anymap into a Palm pixmap
pnmtopalm [-verbose] [-depth N]
[-maxdepth N] [-colormap] [-transparent
color] [-offset]
[-rle-compression|-scanline-compression] [pnmfile]
Reads a PNM image as input, from stdin or pnmfile. Produces
a Palm pixmap as output.
Palm pixmap files are either greyscale 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 ppmquant before you pass it to pnmtopalm. Netpbm
comes with several colormap files you can use with ppmquant 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).
- -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.
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.
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.