Provided is a method of encoding an image, the method including: determining at least one compression unit included in the image; determining a scheme of changing a plurality of samples included in a current compression unit; changing the plurality of samples of the current compression unit based on the determined at least one compression unit and the determined scheme; splitting one of maximum coding units of the image including the changed plurality of samples into at least one coding unit; performing prediction by using at least one prediction unit determined from the at least one coding unit; and encoding the at least one coding unit by performing transformation by using at least one transformation unit determined from the at least one coding unit, wherein the encoding includes generating a bitstream including first information indicating the determined scheme.