Research And Application Of Stack Filters

Nonlinear filters do a good job in suppressing impulsive and multiplicative noisecompared with linear filters. So they are widely used in digital signal processing andimage processing and worthy of research. Stack filters are a class of nonlinear digital filters possessing thresholddecomposition and stacking property. These two important properties ensure that thefiltering go on in binary filed only with easy comparison, addition and multiplication,which allow an efficient VLSI implementation. This paper studies the architecture andtheory of stack filters and the adaptive algorithms for designing stack filters. Someresults of simulation for the proposed algorithms are given to prove their validity. Then a new nonlinear threshold decomposition architecture is introduced to reducethe complexity of algorithms. By combining with the character of image, a dynamicnonlinear decomposition architecture is proposed to implement stack filters which canshorten the running time in the filtering procedure and improve the quality of the outputimage simultaneously. Comparisons on some criterion between this new algorithm andothers are provided to show the validity of our algorithm. Results of the innovative application on SAR images filtering are given in the end,which show that stack filters are approximately with noise filtering algorithms based onlocal statistics property. And as their superior in integration implement, researches inthis part supply for exploring the real time SAR filters.