1. A method of video intraprediction encoding, the method comprising: dividing pixels of an input block into a plurality of groups; performing intraprediction encoding on pixels of a first group among the plurality of groups using pixels of a previously processed neighbor block; reconstructing the intraprediction-encoded pixels of the first group; determining directivities of pixels of remaining groups using the reconstructed pixels of the first group and reconstructed pixels of previously processed other groups; and performing predictive encoding on the pixels of the remaining groups using the reconstructed pixels of the first group and the reconstructed pixels of the previously processed other groups according to the determined directivities and sequentially processing the pixels of the remaining groups in units of a group according to a predetermined order.