Embodiment methods generate a second set of most probable modes (MPMs) from a plurality of intra prediction modes excluding a first set of MPMs for intra prediction or reconstruction of a luma block. An embodiment method constructs a reference block of the luma block, selects a number of samples in the reference block that have been predicted or reconstructed but not in the luma block, and performs intra prediction (or reconstruction) of the selected samples using each of some or all of the plurality of intra prediction modes excluding the first set of MPMs, thereby generating predicted samples (or reconstructed samples) for the selected samples. Based on the predicted samples (or reconstructed samples) and the selected samples, the second set MPM is selected.