libjpeg-turbo is a version of libjpeg which uses MMX, SSE, and SSE2
SIMD instructions to accelerate baseline JPEG compression and
decompression by about 2-4x on x86 and x86-64 platforms. It is based
on libjpeg/SIMD but has numerous enhancements.

The package installs to /opt/libjpeg-turbo by default.
Pass PREFIX=/usr to the SlackBuild to build it system-wide.
