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