Professor Yutaka Yamamoto
Department of Applied Analysis and Complex Dynamical Systems
Graduate School of Informatics
Digital signal processing also aims at designing a digital controller (filter) for an optimal processing of analog signals. While this has much in common with sampled-data control theory, the primary analog model employed thus far is based on Shannon perfect band-limited assmption.
We observe that this can often lead to a fairly undesirable result, e.g., harsh ringing in CD processing, block and mosquito noise in digital images, and show that sampled-data theory can provide an optimal platform to circumvent such defects. We will give a new design method based on H-infinity sampled-data control theory not based on the perfect band-limited hypothesis. Examples of sound/image processing will be presented to illustrate the advantage of the proposed theory.