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

A method of decoding points of a point cloud sensed by at least one sensor associated with a sensor index from a bitstream of encoded point cloud data, wherein the method comprises:

• decoding, from the bitstream, an information (I(SP)) representing a sensing path wherein
• the sensing path is defined in a two-dimensional angular coordinate space comprising an azimuthal coordinate representative of an azimuthal angle representing a sensing angle of a sensor relative to a referential and an elevation coordinate representative of an elevation angle of a sensor relative to a horizontal referential plane;
• the sensing path has been used to sense the points of the point cloud according to ordered coarse points representing potential locations of sensed points of the point cloud, each coarse point being defined in the two-dimensional angular coordinate space from one sample index associated with a sensing time instant and one sensor index associated with a sensor;
• the sample index is defined along the sensing path according to a sensing scheme;
• for each point (P) of the point cloud,
• obtaining one sensing point (Pover(s)) in the two-dimensional angular coordinate space from a sample index(s) associated with a sensing time instant of the point (P) of the point cloud along the sensing path, and the sensing scheme;
• obtaining a coarse point (Pλ(s)) in the two-dimensional angular coordinate space by shifting the sensing point (Pover(s)) in the two-dimensional angular coordinate (φ,θ) space with shifting values that depend on the sensor index (λ) associated with the sensor that sensed the point (P) of the point cloud;
• and
• decoding a point of the point cloud relatively to the coarse point (Pλ(s));
• wherein angular coordinates (φλ,θλ) of the coarse point (Pλ(s)) are obtained by shifting angular coordinates of the sensing point (Pover(s)) in the two-dimensional angular coordinate space by an azimuthal angle shifting coefficient (δφλ) and an elevation angle shifting coefficient (δθλ), both depending on the sensor index (λ);
• wherein the angular coordinates (φλ,θλ) of the coarse point (Pλ(s)) is obtained by further shifting the angular coordinates of the sensing point (Pover(s)) in the two-dimensional angular coordinate space by an offset depending on a sensing delay (Δtλ) and a two-dimensional angular velocity (ν(s)) of the sensing point (Pover(s)).

An apparatus of encoding points of a point cloud sensed by at least one sensor associated with a sensor index into a bitstream of encoded point cloud data, wherein the apparatus comprises at least one processor configured to:

• encode, into the bitstream, an information (I(SP)) representing a sensing path,
• wherein the sensing path is defined in a two-dimensional angular coordinate space comprising an azimuthal coordinate representative of an azimuthal angle representing a sensing angle of a sensor relative to a referential and an elevation coordinate representative of an elevation angle of a sensor relative to a horizontal referential plane;
• and
• the sensing path is used to sense the points of the point cloud according to ordered coarse points representing potential locations of sensed points of the point cloud, each coarse point being defined in the two-dimensional angular coordinate space from one sample index associated with a sensing time instant and one sensor index associated with a sensor;
• wherein the sample index is defined along the sensing path according to a sensing scheme;
• for each point (P) of the point cloud,
• obtain one sensing point (Pover(s)) in the two-dimensional angular coordinate space from a sample index(s) associated with a sensing time instant of the point (P) of the point cloud along the sensing path, and the sensing scheme;
• obtain one coarse point (Pλ(s)) in the two-dimensional angular coordinate space by shifting the sensing point (Pover(s)) in the two-dimensional angular coordinate (φ,θ) space with shifting values that depend on the sensor index associated with the sensor that sensed the point (P) of the point cloud;
• and
• encode, into the bitstream, the point (P) of the point cloud relatively to the coarse point (Pλ(s));
• wherein angular coordinates (φλ,θλ) of the coarse point (Pλ(s)) is obtained by shifting angular coordinates of the sensing point (Pover(s)) in the two-dimensional angular coordinate space by an azimuthal angle shifting coefficient (δφλ) and an elevation angle shifting coefficient (δθλ), both depending on the sensor index (λ);
• wherein the angular coordinates (φλ,θλ) of the coarse point (Pλ(s)) is obtained by further shifting the angular coordinates of the sensing point (Pover(s)) in the two-dimensional angular coordinate space by an offset depending on a sensing delay (Δtλ) and a two-dimensional angular velocity (ν(s)) of the sensing point (Pover(s)).