JPEG-LS is the emerging ISO standard for lossless/near-lossless compression of continuous-tone images. Marcelo Weinberger says about it:
JPEG-LS is being developed by ISO/IEC JTC1/SC29/WG1 (final committee draft document FCD14495-1 as of July 1997), and it is based on HP's LOCO-I algorithm.[3]
The main feature of JPEG-LS is its superior placement in the compression/complexity trade-off curve. Tested over a wide variety of image types, it was shown to be, on the average, within about 4% of the best available lossless image compression at a fraction of the complexity. In particular, JPEG-LS significantly outperforms FELICS and lossless JPEG Huffman at similar levels of complexity (it also outperforms lossless JPEG arithmetic, which is of significantly higher complexity). [...]
A software implementation of JPEG-LS, is now available at
http://www.hpl.hp.com/loco/ There, the DCC'96 paper on LOCO-I is also available. The standard draft is also available through a link to the official JPEG Web site.