CPC G06T 9/00 (2013.01) [H04N 19/33 (2014.11); H04N 19/593 (2014.11)] | 13 Claims |
1. A three-dimensional data encoding method, comprising:
selecting, as one or more candidates for calculating a predicted value of attribute information of a first three-dimensional point, one or more three-dimensional points from a plurality of three-dimensional points based on one or more distances from the first three-dimensional point;
calculating a predicted value using pieces of attribute information of the one or more three-dimensional points selected as the one or more candidates;
calculating a prediction residual that is a difference between (i) the attribute information of the first three-dimensional point and (ii) the predicted value calculated; and
generating a bitstream, based on the prediction residual,
wherein in the selecting, when the plurality of three-dimensional points include three-dimensional points equidistant from the first three-dimensional point, the one or more candidates are selected based on a first Morton code of the first three-dimensional point,
the plurality of three-dimensional points are one-dimensionally arranged in order of Morton codes, belong to a first layer higher than a layer to which the first three-dimensional point belongs, and comprise a first group and a second group,
the first group includes one or more third three-dimensional points having Morton codes closer to the first Morton code than other three-dimensional points included in the plurality of three-dimensional points,
the second group neighbors the first group, and the second group includes one or more fourth three-dimensional points having Morton codes greater than the first Morton code, the one or more fourth three-dimensional points belonging to the first layer,
the second group is searched for the one or more candidates after the first group, and
when the third three-dimensional points included in the first group are selected as the one or more candidates, and a distance between the first three-dimensional point and one of the one or more third three-dimensional points is equal to a distance between the first three-dimensional point and one of the one or more fourth three-dimensional points, the one or more third three-dimensional points are maintained as the one or more candidates.
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