OIC - Optimized Image Compression
Image Compression Library I developed in 1990.
It uses a lossy DCT algorithm and was up and running before the JPEG specification (which also uses DCT based compression) was finalized.
Many of the functions were originally written in C, but I converted them to x86 assembly to maximize performance.
If you are wondering why the odd filenames - any code on MSDOS / PC was done that way in 1990. Everything was on a MSDOS 8.3 naming convention. (So the extensions are capitalized on case-sensitive filesystems)