1. An apparatus for processing an image comprising: an interface configured to receive color information including three variables representing a color of each of a plurality of pixels which constitute the image; and a processor configured to derive a target characteristic value corresponding to a target pixel among the plurality of pixels based on the three variables of the target pixel, derive proximate characteristic values corresponding to a plurality of proximate pixels which are proximate to the target pixel, and replace the three variables of the target pixel with the three variables of one of the proximate pixels depending on a relationship between the target characteristic value and the proximate characteristic values.