Icon Heaven library
Icon Heaven library (.FIM) is a compressed icon library format associated with the OS/2 shareware utility Icon Heaven, by Paul van Keep. FIM probably stands for Frobozz Icon Manager, which is apparently the software's nickname.
See also OS/2 Icon.
Contents |
Format details
[This section contains unconfirmed information based on reverse engineering. Written for the fileformats.archiveteam.org wiki.]
File structure
A FIM file consists of a 140-byte header, followed by a sequence of icon segments. The two-byte integer at offset 8 is the number of icons.
An icon segment consists of:
- ASCII "
ci" - Compressed size
- Original size
- Unknown 2-byte field
- Name length
- Name
- Compressed data
An icon decompresses to a complete file, in OS/2 Icon or Bitmap Array format.
Compression
The compression scheme is a kind of LZW. Technical information follows.
All codes are 9 bits, msb-first. The code table is cleared after every 256 nonspecial codes. The only known special codes are if the very first code is 510 or 511.
Special code 510 decodes to a particular 88-byte sequence that is common in files whose decompressed size is 3498 bytes.
Special code 511 decodes to a particular 75-byte sequence that is common in files whose decompressed size is 888 bytes.
Identification
Known files begin with bytes 4c 49 00 01 00 00 00 00.
Software
- Icon Heaven
- Deark
Sample files
- Some FIM files are included with Icon Heaven (see above).
- ticn10ih.zip - THE OS/2 Icon Collection #10, Icon Heaven edition
- dexvert samples — archive/iconHeaven
Links
- Icon Heaven article at OS/2 World.Com Wiki
