Several systems and methods for intra-prediction estimation of video pictures are disclosed. In an embodiment, the method includes accessing four ‘N×N’ pixel blocks comprising luma-related pixels. The four ‘N×N’ pixel blocks collectively configure a ‘2N×2N’ pixel block. A first pre-determined number of candidate luma intra-prediction modes is accessed for each of the four ‘N×N’ pixel blocks. A presence of one or more luma intra-prediction modes that are common among the candidate luma intra-prediction modes of at least two of the four ‘N×N’ pixel blocks is identified. The method further includes performing, based on the identification, one of (1) selecting a principal luma intra-prediction mode for the ‘2N×2N’ pixel block and (2) limiting a partitioning size to a ‘N×N’ pixel block size for a portion of the video picture corresponding to the ‘2N×2N’ pixel block.