SCIENCE & ENGINEERING NEWS
San Diego, CA — When most people think geometry and triangles, they think of things like the Pythagorean theorem – A2 + B2 = C2. But Jason Meserve reports that two scientists are now taking triangles to a whole new level, using them to compress digital images up to 12 times better than current standards.
Wim Sweldens of Bell Labs’ Mathematical Sciences Research Center and Peter Schroeder, a professor of science at the California Institute of Technology, have developed an algorithm that uses “digital geometry compression” to shrink files even further than current levels. Their technology can be used to represent images in a computer using billions of tiny triangles.
The pair has developed a small application that they used to demonstrate the technique at the recent Siggraph 2000 Conference in New Orleans.
By creating smaller files, companies can more easily and less expensively transfer complex images across the Internet because of the use of low-bandwidth connections. The current active compression champion is MPEG4, which is mainly used for streaming audio and video across the Internet.
Sweldens and Schroeder foresee their algorithm being used for high-resolution, three-dimensional images that can be downloaded to a computer and rotated on a screen by the user. He says the technology could be used in business-to-business and business-to-consumer applications such as delivering a building blueprint that can be viewed from any angle.
MPEG4’s target for efficient compression is VHS-quality video over 64K bit/sec of bandwidth. Assuming that Sweldens’ and Schroeder’s algorithm is 12 times better, high-quality images could be easily transmitted over a 56K bit/sec dial-up connection.
Sweldens’ and Schroeder’s compression technology removes some of the excess parameter and connectivity information used in other algorithms.
The duo also uses wavelet compression technology to help achieve their 12-fold performance increase. Wavelet technology compresses an image rather then breaking it into squares and compressing them, as does the current JPEG standard.
When will the pair’s technology be available for general use? “Standards have a way of evolving based on political pressures,” Sweldens says. “But we believe the performance impact is so large, that it cannot be ignored.”