Information processing apparatus and method

An information processing method comprising:

• performing hierarchization of attribute information about a point cloud representing a three-dimensional object by recursively repeating, on a reference point, a process of classifying points of the point cloud into a prediction point that is a point at which a difference value between the attribute information and a predicted value is left, and the reference point that is a point at which the attribute information is referred to during derivation of the predicted value;
• and
• selecting, during the hierarchization, the prediction point in such a manner that a point also exists in a voxel of a hierarchical level one level higher than a hierarchical level to which voxels containing points of a current hierarchical level belong.

An information processing apparatus comprising

• an inverse hierarchization unit that performs inverse hierarchization of attribute information about a point cloud representing a three-dimensional object, the attribute information having been hierarchized by recursively repeating, on a reference point, a process of classifying points of the point cloud into a prediction point that is a point at which a difference value between the attribute information and a predicted value is left, and the reference point that is a point at which the attribute information is referred to during derivation of the predicted value,
• wherein, during the inverse hierarchization, the inverse hierarchization unit derives the predicted value of the attribute information about the prediction point at each hierarchical level using the attribute information about the reference point and positional information at a resolution of a hierarchical level that is not the lowest hierarchical level of the point cloud, and derives the attribute information about the prediction point using the predicted value and the difference value.

An information processing method comprising:

• performing inverse hierarchization of attribute information about a point cloud representing a three-dimensional object, the attribute information having been hierarchized by recursively repeating, on a reference point, a process of classifying points of the point cloud into a prediction point that is a point at which a difference value between the attribute information and a predicted value is left, and the reference point that is a point at which the attribute information is referred to during derivation of the predicted value;
• and deriving, during the inverse hierarchization, the predicted value of the attribute information about the prediction point at each hierarchical level using the attribute information about the reference point and positional information at a resolution of a hierarchical level that is not the lowest hierarchical level of the point cloud, and deriving the attribute information about the prediction point using the predicted value and the difference value.

An information processing apparatus comprising:

• a generation unit that generates information indicating a hierarchical structure of positional information about a point cloud representing a three-dimensional object;
• and
• a hierarchization unit that hierarchizes attribute information about the point cloud to associate the attribute information with the hierarchical structure of the positional information, on a basis of the information generated by the generation unit.

An information processing apparatus comprising:

• a generation unit that generates information indicating a hierarchical structure of positional information about a point cloud representing a three-dimensional object;
• and
• an inverse hierarchization unit that inversely hierarchizes attribute information about the point cloud, to associate a hierarchical structure of the attribute information with the hierarchical structure of the positional information, on a basis of the information generated by the generation unit.