SYNOPSIS

ppmtowinicon [-andpgms] [-output output.ico] [ppmfiles...]

DESCRIPTION

Reads one or more portable pixmaps as input. Produces a Microsoft Windows .ico file as output.

A Windows icon contains 1 or more images, at different resolutions and color depths.

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.

OPTIONS

-andpgms

If this option is given, every second file is read as an "and mask" to be used by windows for transparency data for the previous 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 represented as binary numbers, then corresponding bits of the background and foreground intensities are exlusive-or'ed together. So there is a sort of reverse video effect.

-output output.ico

File to write. By default, the icon is written to stdout.

AUTHOR

Copyright (C) 2000 by Lee Benfield.