Device and method of median filtering

A median filter device to obtain a middle value of N signal data stored therein in each clock cycle, wherein N is an odd number greater than 1;

• the median filter device comprises:
• a data buffer circuit with a length of N−1 signal data, for storing last N−1 signal data of a sequence of signal data sequentially received by the median filter device during a preceding clock cycle, wherein each signal data has a numerical value;
• a data encoding circuit with a length of N−1 signal data, for encoding the signal data stored in the data buffer circuit into signal codes according to the numerical values of the signal data;
• a reorder circuit connected with the data buffer circuit and the data encoding circuit, for sorting all the signal data stored in the data buffer circuit according to their corresponding signal codes from small to large or large to small to obtain a sequence of reordered signal data;
• a comparison circuit connected with the reorder circuit, for comparing a new signal datum entering the median filter device in the current clock cycle with the N−1 signal data in the sequence of the reordered signal data, and inserting the new signal datum into the sequence of the reordered signal data according to the numerical value of the new signal datum to form a new signal data sequence of N signal data stored in the median filter device in the current clock cycle from large to small or small to large, and generating a median of the N signal data stored in the median filter device in the current clock cycle;
• and
• a data refresh circuit connected with the comparison circuit and the data encoding circuit, for encoding rest N−1 signal data except for signal data to leave the median filter device in the current clock cycle into new signal codes according to their numerical values, and updating the signal codes stored in the data encoding circuit with the new signal codes according to the entry sequence of the rest N−1 signal data.