1. An image encoding method comprising operations of: performing predictive-encoding on a first color component pixel block of a first color component image of an input image; performing motion estimation on at least one of other color component pixel blocks corresponding to the first color component pixel block in order to generate a first prediction pixel block candidate for the at least one of the other color component pixel block(s); reconstructing the predictive-encoded first color component pixel block; predicting the at least one of the other color component pixel blocks using the reconstructed first color component pixel block in order to generate a second prediction pixel block candidate for the at least one of the other color component pixel blocks; and determining one of the first prediction pixel block candidate and the second prediction pixel block candidate to be a prediction pixel block of the at least one of the other color component pixel blocks.