Abstract

A median filter can provide easier implementation and a simplified change of the degree. The median filter comprises an input end, a plurality of median cells for storing one data, wherein each of the median cells is connected to the input end, an upstream median cell and a downstream median cell, and an output end for outputting the output of a median cell which is located in the middle of the plurality of the median cells as a middle value of data stored in the plurality of median cells, wherein the plurality of the median cells perform deleting the earliest data input via the input end among sorted and stored data, iterating an operation for storing in the data-deleted median cell the data stored in the downstream median cell thereof, up to the most downstream median cell, and resorting data received via the input end and the stored data in the manner that each median cell performs, in the case of receiving no data from the upstream median cell, comparing the stored data with the data received via the input end, selecting one of the two data according to the comparison result, outputting the stored data to the downstream median cell, and storing the data received via the input end when the selected data is the data received via the input end, and in the case of receiving data from the upstream median cell, outputting the stored data to the downstream median cell and storing the data applied from the upstream median cell.