ppmtowinicon – convert 1 or more portable pixmaps into a Windows .ico
ppmtowinicon [-andpgms] [-output output.ico] [ppmfiles…]
Reads one or more portable pixmaps as input. Produces a Microsoft Win‐
dows .ico file as output.
A Windows icon contains 1 or more images, at different resolutions and
Microsoft recommends including at least the following formats in each
icon (size and bits-per-pixel):
16 x 16 – 4 bpp
32 x 32 – 4 bpp
48 x 48 – 8 bpp
Default I/O is STDIN/STDOUT.
If this option is given, every second file is read as an “and
mask” to be used by windows for transparency data for the previ‐
ous image. (These are set to fully opaque by default). The and
mask is a PGM image, where any pixel with maxval intensity means
opaque and any other pixel means not opaque. Note that as with
all Netpbm programs, you may use a PBM file here and it will be
used as if it were the equivalent PGM.
The and mask is like an alpha mask, except for what it signifies
in the “not opaque” areas. In the usual case, the foreground
image is black in those areas, and in that case the areas are
fully transparent — the background shows through the icon. But
in general, a not opaque pixel signifies that the background and
foreground should be merged as follows: The intensities of the
color components in the forgeground and background are repre‐
sented as binary numbers, then corresponding bits of the back‐
ground and foreground intensities are exlusive-or’ed together.
So there is a sort of reverse video effect.
File to write. By default, the icon is written to stdout.
Copyright (C) 2000 by Lee Benfield.
22 May 2000 ppmtowinicon