En-Hui Yang

Canada Research Chair in Information Theory and Applications

Tier 1 - 2017-11-01
Renewed: 2017-06-01
University of Waterloo
Natural Sciences and Engineering Research Council

519-888-4567 ext./poste 2873

Research involves

Extending the application of the universal coding system to include efficient compression of multimedia data files.

Research relevance

The development of superior compression technologies will enhance the storage capacity of computers and make the transmission of data faster and more reliable.


Imagine a company in the balloon manufacturing business. Once the balloons are made, the flat pieces of plastic are inflated, and then stored in an enormous warehouse. When it comes time to ship the balloons, it takes a fleet of trucks to carry only a few hundred at a time. It sounds ridiculous, but computer users and data transmission servers do this kind of thing every day. Most data files are stored or transmitted without being compressed. As large hard drives with vast memory capacity have become commonplace, computer users overlook the fact they're wasting valuable space. Data transmission has also sped up dramatically, thanks to the advent of fibre optic networks, but they, too, carry the data equivalent of a shipment of inflated balloons. Dr. En-hui Yang is co-developer of the Yang-Kieffer algorithm, a numerical set of rules employing grammar-based coding to achieve lossless compression of text and image files. Compression programs applying this technique can take the "air" out of "data balloons" and then "re-inflate" them to their exact original size and shape - that's essentially what lossless compression and de-compression is all about. The process outperforms all other existing methods by several orders of magnitude. Dr. Yang's outstanding and novel contribution to the field of data compression and information theory is being recognized by his appointment to a Canada Research Chair. The next phase of Dr.Yang's research is aimed, in part, at developing ways to compress huge multimedia files with as high efficiency as possible. As demand soars for seamless, error-free storage and transmission of sound and video files, new compression technologies are essential, and Dr. Yang's work goes a long way toward meeting this need.