A method for performing an intra prediction according to the present invention may comprise the steps of: generating predicted pixels by performing interpolation using N reference pixels including two adjacent reference pixels according to an intra prediction direction; and generating a residual signal by using the generated predicted pixels. Accordingly, when a prediction for generating the residual signal is performed according to each prediction direction (mode), an optimal filtering method is determined and a predicted value is acquired, so that a size of the residual signal can be minimized and compression performance can be improved.