To execute a median filtering processing by comparing the two pieces of data at the center of the eight pieces of numerical data for which one piece of the data is excluded from the nine pieces of the numerical data with the excluded one piece of the data and outputting the median of the three pieces of the data.

The larger output A of a binary extraction circuit and 9th data input 9 are inputted to a comparator circuit 20. Then, the output of the comparator circuit 20 and the smaller output B of the binary extraction circuit are inputted to the comparator circuit 21. Thus, the data outputted from the large output terminal of the comparator circuit 21 become the median of the three pieces of the data of the output A and B and the input 9, that is the median of the input 1-9. Thus, this median extraction circuit is the circuit for which the binary extraction circuit and a ternary comparator circuit are combined, extracts the center two pieces of the eight pieces of the data in the nine pieces of input data, compares the three data to which the remaining one piece is added and outputs the median by a simple circuit. Thus, operation time is about delay time in a resistor or the like inside the circuit and high-speed median output is made possible.