State Description for the Root Signal Sets of Stack Filters
| Autor: | Lin, Kuen Ying, 林昆穎 |
|---|---|
| Rok vydání: | 1993 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 81 Stack filters are nonlinear digital filters that are based on positive Boolean functions as the window operators and contain some roots (fixed points) which are invariant under filtering operations. For some applications, it is useful to understand the root structure of a stack filter (e.g. median filter). Provably, the problem determining whether a specific signal is a fixed point of some stack filter can be regarded as a pattern recognizing problem by a deterministic finite automaton which corresponds to the specified stack filter and generates the regular language. We will introduce a concise and direct algorithm to obtain a simplified deterministic finite automaton that describes the root set of a specified stack filter. From the automaton, we can easily determine root properties of a stack filter. We will also introduce a new class of stack filters called K-monotone stack filters that are generalizations of median filters and apply our algorithm to analyze root properties of K-monotone stack filters (K .ltorsim. 2N+1). An open problem concerning the root structures of median filters under circular appending strategy is analyzed by the approach of state description. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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