Frame theory, irregular sampling in spline-type spaces and realizable algorithmsHans G. Feichtinger given at ofoa (17.01.10) id: 1501 length: min status: accepted type: LINK-Presentation: https://nuhagphp.univie.ac.at/dateien/talks/1501_ConstrFei00.pdf ABSTRACT: Workshop at the Univ. of San Francisco: (organized by Dave Larson and Shidong Li) Frames and Riesz bases (e.g. for spline-type spaces) are valuable tools for a variety of applications, such as the irregular sampling for band-limited functions, the reconstruction from local averages, or even coorbit theory. One has the idea that the description of a constructive algorithm is enough to claim that one has described a practical tool. However, in most cases the necessary steps (building a perfect nearest neighborhood interpolation, projecting perfectly onto the multi-window spline-type space etc.) are NOT REALIZABLE on a computer. Hence it is necessary to develop/describe concepts which allow to say: Given a (family of) Banach spaces suitable to describe the problem and some (admitted relative) error level eps > 0 one can find a realizable method (something that we can do for example using MATLAB on our notebooks) which does a - up to that given error level for that specific norm - good job on all the elements of the space under consideration. The idea is to really have a finite implementation for the continuous (multi-dimensional) problem. Doing the (integral transform) FT (Fourier transform) using FFTs is a prototype of such a problem, or methods of finding dual Gabor atoms using the finite Gabor toolbox (work of N.Kaiblinger) . |