A Fast Algorithm for 3x3 Median Filtering † † Tomoyuki Hamamura Bunpei Irie 5 30 n Find[4],Select[5] Smith [6] 19 [2] U [2][4] 8 d 8 U d Kopp [1] 2 8.87 9.5 0.5 2 9 2.1 step 1 9 3 3 unit unit step 2 unit step 2 unit unit unit A B C step 2 case 1 unit B x x 3 x 3 x 2 y z y unit A z unit C step 3 y z x step 3 case 1 y<=x<=z z<=x<=y x case 2 x<y x<z x 6 x 5 x 5 unitA unitB w z unit A 3 y y z w step 4