Dr. James Walker from the University of Wisconsin, Eau Claire, will discuss “A New Wavelet-Based Image Compression Algorithm” at 3 p.m. today in 3M Auditorium, Owens Science Hall. Refreshments will be available at 2:45.

The lossy image compression method employs a dynamic scanning procedure for encoding wavelet-transformed image data, which allows for progressive transmission over limited capacity channels, for selective encoding of regions of interest, and for improved image denoising. The compression ratios obtained with this method are similar to some standard wavelet methods (such as the SPIHT method), and the image denoising is superior to several commonly used methods (such as shrinkage and Wiener filtering).

Walker has a bachelor of science degree from the State University of New York at Buffalo, a master of science degree from the University of Illinois-Urbana-Champaign and a Ph.D. from the University of Illinois at Chicago. He is the author of three books: Fourier Analysis; Fast Fourier Transforms and A Primer on Wavelets, and papers on complex analysis, FFTs, wavelets, and image processing.

His talk is a Center for Applied Mathematics colloquium, which is open to all.