ToICO

Toico converts PNG, GIF, TIFF, BMP, XPM and ICNS images to the Windows icon format (ICO). It is possible to create multi-resolution icon with full alpha channel. Program compiles on Linux.

Usage example:

toico icon-16x16.png icon-32x32.png -vo favicon.ico

Command line options:

toico [-v] img1-opts img1 [img2-opts img2]... [-o icon]
toico [-l] [icon.ico]
toico [-h]
 -o  Output to a file instead of stdout
 -l  List icon
 -v  Verbose
img opts:
 -e  Embed raw PNG
 -1  Force 1-bit transparency
 -i num  Image index in file
 -k RRGGBB  Transparency key (eg. magenta: FF00FF)

Download: toico-2.4.tar.gz (source, 2022-06-06)

Libraries (optional): libpng, libtiff, zlib.

Note: MIME type of ICO is image/vnd.microsoft.icon.