Method and apparatus of encoding/decoding point cloud geometry data sensed by at least one sensor

A method of decoding, from a bitstream, point cloud geometry data represented by geometrical elements occupying some discrete positions of a set of discrete positions of a multi-dimensional space, wherein the method comprises:

• obtaining, a series of at least one binary data (fj,n) based on occupancy data of precedingly decoded geometrical elements belonging to a causal neighborhood of a current geometrical element of the multi-dimensional space;
• obtaining, a first index (I1) from the series of at least one binary data (fj,n), the first index (I1) being representative of a neighborhood occupancy configuration among a first set of neighborhood occupancy configuration indices representative of potential neighborhood occupancy configurations;
• obtaining a second index (I2) by applying an index range reduction function (F) to the first index (I1);
• the second index (I2) is representative of the neighborhood occupancy configuration among a second set of neighborhood occupancy configuration indices representative of the potential neighborhood occupancy configurations;
• each index of the first set of neighborhood occupancy configuration indices being mapped to an index of the second set of neighborhood occupancy configuration indices according to the index range reduction function;
• and
• the range of the second set of neighborhood occupancy configuration indices being lower than the range of the first set of neighborhood occupancy configuration indices;
• and
• entropy decoding), from the bitstream, at least one binary data (fj) representative of an occupancy data of the current geometrical element based on the second index (I2).

An apparatus of encoding, into a bitstream, point cloud geometry data represented by geometrical elements occupying some discrete positions of a set of discrete positions of a multi-dimensional space, wherein the apparatus comprises at least one processor configured to:

• obtaining a series of at least one binary data (fj,n) representative of an occupancy data of at least one neighboring geometrical element belonging to a causal neighborhood of a current geometrical element of the multi-dimensional space;
• obtaining a first index (I1) from the series of at least one binary data (fj,n), the first index (I1) being representative of a neighborhood occupancy configuration among a first set of neighborhood occupancy configuration indices representative of potential neighborhood occupancy configurations;
• obtaining a second index (I2) by applying an index range reduction function (F) to the first index (I1);
• the second index (I2) is representative of the neighborhood occupancy configuration among a second set of neighborhood occupancy configuration indices representative of the potential neighborhood occupancy configurations;
• each index of the first set of neighborhood occupancy configuration indices being mapped to an index of the second set of neighborhood occupancy configuration indices according to the index range reduction function;
• and
• the range of the second set of neighborhood occupancy configuration indices being lower than the range of the first set of neighborhood occupancy configuration indices;
• and
• entropy encoding, into the bitstream, at least one binary data (fj) representative of an occupancy data of the current geometrical element based on the second index (I2).