The LJPEG-E core implements Lossless JPEG (LJPEG) compression in a compact, high-performance, stand-alone package
ideal for applications where bit-by-bit accurate reproduction of an image is essential.
The LJPEG-E conforms to the spatial (sequential) lossless encoding mode (SOF3) of the ISO/IEC 10918-1 standard
(CCITT T.81 recommendation). Rather than the Discrete Cosine Transform (DCT) functions used for lossy JPEG
compression - which can introduce round-off errors - the LJPEG-E employs a predictor function as described in the
specification. It thus encodes and compresses images with no information loss, and requires a significantly
smaller physical implementation.
Evaluation designs show that the core requires just 21K gates in an ASIC (0.09µ process / typical conditions)
and that it also fits in a variety of low-end and high-end FPGA devices.
Its heavily optimized architecture also enables very high performance, reaching 500 MSamples/sec on
ASICs and 200 MSamples/sec on FPGAs.
The LJPEG-E is a fully synchronous, strictly positive-edge design with no internal three-state buffers.
Comprehensive documentation and a complete verification environment - including a bit-accurate model - help designers
integrate and verify the core.
The LJPEG-E provides a fast, economical solution whenever lossless image compression is essential,
including applications such as:
Medical, military, and space imaging.
Professional, studio quality cameras and editing suites.
High-end film and photo scanners.
Industrial machine vision systems.