Provided are an apparatus for removing ringing noise and an apparatus for removing noise. The apparatuses includes a representative value setting block dividing pixel data in one block including a plurality of pixel data into two groups through a K-means algorithm and setting a representative value in each of the groups; a parameter generator block calculating intervals and approaches between all the pixel data in the block and a pair of the representative values; and a correction block correcting an inputted pixel data value using the intervals and the approaches.