1. A method for determining median of an array comprising: sorting each column of a high-order array in ascending order to form a first sorted high-order array; sorting each row of the first sorted high-order array in ascending order to form a second sorted high-order array; selecting values from diagonal portion of the second sorted high-order array to form a low-order array; and calculating a median value of the low-order array as representing median value of the high-order array.