Device for determining the rank of a sample, an apparatus for determining the rank of a plurality of samples, and the i^th rank ordered filter

摘要

A rank-determining device determines the rank of a particular sample value from a set of digital sample values by utilizing two different thresholders that are implemented by comparators. The rank of the sample value is decomposed by thresholding the sample value with all of the sample values in the set of digital sample values, and in this manner eliminates the necessity of a sorting operation. This decomposition of the rank will is referred to as self-threshold decomposition. A plurality of these rank-determining devices can be combined to form a rank determining apparatus in order to find the rank of each one of the digital samples in the set of digital samples. Because the rank-determining apparatus implements self-threshold decomposition, rank- and order-statistic based filters, such as the median filter, can be realized in a feasible manner.