# US 12,711,667 B2 · Method and apparatus of encoding/decoding point cloud geometry data sensed by at least one sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,711,667 B2 - Document ID: US12711667B2 - Status: Granted - Kind: B2 - Application number: 18/693,598 - Filed: 2022-06-21 - Published: 2025-05-01 - Granted: 2026-08-18 - Earliest claimed: 2021-09-24 - Assignees: Beijing Xiaomi Mobile Software Co., Ltd. - Applicants: Beijing Xiaomi Mobile Software Co., Ltd. - Inventors: Sebastien Lasserre; Jonathan Taquet - Web page: https://patentgrep.com/patent/US12711667B2 ## CPC - G06T 9/001: {Model-based coding, e.g. wire frame} - H04N 19/91: Entropy coding, e.g. variable length coding [VLC] or arithmetic coding - G06T 9/005: {Statistical coding, e.g. Huffman, run length coding} - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method of encoding, into a bitstream, point cloud geometry data represented by ordered coarse points occupying some discrete positions of a set of discrete positions of a two-dimensional space, includes obtaining at least one binary data (fj) representative of an order index difference representative of a difference between order indices of two consecutive occupied coarse points and encoding each of the at least one binary data (fj) by: obtaining coordinates (sj,λj) of a current coarse point (Pj) within the two-dimensional space; obtaining a sensing number (Nsens(sj,λj)) from the current coarse point (Pj), the sensing number (Nsens(sj,λj)) being representative of an average number of consecutive sensing needed by a sensor (λj) associated with the current coarse point (Pj) to sense another coarse point; and entropy encoding, into the bitstream, the binary data (fj) based on the sensing number (Nsens(sj,λj)). ## Claims ### Claim 1 A method of encoding, into a bitstream, point cloud geometry data represented by ordered coarse points occupying some discrete positions of a set of discrete positions of a two-dimensional space, wherein the method comprises obtaining at least one binary data (fj) representative of an order index difference representative of a difference between order indices of two consecutive occupied coarse points and encoding each of the at least one binary data (fj) by: obtaining coordinates (sj,λj) of a current coarse point (Pj) within the two-dimensional space; obtaining a sensing number (Nsens(sj,λj)) from the current coarse point (Pj), the sensing number (Nsens(sj,λj)) being representative of an average number of consecutive sensing needed by a sensor (λj) associated with the current coarse point (Pj) to sense another coarse point; and entropy encoding, into the bitstream, the binary data (fj) based on the sensing number (Nsens(sj,λj)). ### Claim 2 A method of decoding, from a bitstream, point cloud geometry data represented by ordered coarse points occupying some discrete positions of a set of discrete positions of a two-dimensional space, wherein the method comprises obtaining at least one binary data (fj) representative of an order index difference representative of a difference between order indices of two consecutive occupied coarse points by: obtaining coordinates of a current coarse point (Pj) within the two-dimensional space; obtaining a sensing number (Nsens(sj,λj)) from the current coarse point (Pj), the sensing number (Nsens(sj,λj)) being representative of an average number of consecutive sensing needed by a sensor (λj) associated with the current coarse point (Pj) to sense another coarse point; and entropy decoding, into the bitstream, the binary data (fj) based on the sensing number (Nsens(sj,λj)). ### Claim 3 (depends on 1) The method of claim 1, wherein entropy encoding the binary data (fj) is based on the sensing number (Nsens(sj,λj)) in response to the sensing number (Nsens(sj, λj)) being greater than an activation threshold (thactivation); or based on at least a coordinate difference (Cj) between one first coordinate associated with the current coarse point (Pj) and one first coordinate of a preceding encoded or decoded coarse point (Pprec) with a same sensor index as a sensor index (λj)) associated with the current coarse point, in response to the sensing number (Nsens(sj, λj)) not being greater than the activation threshold (thactivation). ### Claim 4 (depends on 1) The method of claim 1, wherein entropy encoding the binary data (fj) is based on a value (Δj) depending on a sample index (sj), another sample index (slast) associated with a sensing time instant at which a point of the point cloud, represented by a last occupied coarse point (Plast), has been sensed by the sensor associated with the sensor index (λj), and the sensing number (Nsens(sj,λj)). ### Claim 5 (depends on 4) The method of claim 4, wherein the value (Δj) is bounded by two thresholds. ### Claim 6 (depends on 1) The method of claim 1, wherein the sensing number (Nsens(sj,λj)) depends on at least one of a radius (robject) or an azimuthal angle (φlast) associated with a last occupied coarse point (Plast) representing a point of the point cloud sensed by the sensor (λj) associated with the current coarse point (Pj). ### Claim 7 (depends on 1) The method of claim 1, wherein the sensing number (Nsens(sj,λj)) depends on a point cloud characteristic distance (LPC), defining a mean distance between points of the point cloud, and on an arc length (Larc) defined in a two-dimensional cartesian coordinate plane between two consecutive sensing by the sensor associated with the current coarse point. ### Claim 8 (depends on 7) The method of claim 7, wherein the arc length (Larc) is based on a radius associated with a last occupied coarse point (Plast) representing a point of the point cloud sensed by the sensor associated with the current coarse point and an azimuthal shift between two consecutive sensing. ### Claim 9 (depends on 7) The method of claim 7, wherein the point cloud characteristic distance (LPC) is encoded into the bitstream. ### Claim 10 An apparatus of encoding, into a bitstream, point cloud geometry data represented by ordered coarse points occupying some discrete positions of a set of discrete positions of a two-dimensional space, wherein the apparatus comprises at least one processor configured to obtain at least one binary data (fj) representative of an order index difference representative of a difference between order indices of two consecutive occupied coarse points and encoding each of the at least one binary data (fj) by: obtaining coordinates (sj,λj) of a current coarse point (Pj) within the two-dimensional space; obtaining a sensing number (Nsens(sj,λj) from the current coarse point (Pj), the sensing number (Nsens(sj,λj)) being representative of an average number of consecutive sensing needed by a sensor (λj) associated with the current coarse point (Pj) to sense another coarse point; and entropy encoding, into the bitstream, the binary data (fj) based on the sensing number (Nsens(sj,λj)). ### Claim 11 (depends on 2) An apparatus of decoding, from a bitstream, point cloud geometry data represented by ordered coarse points occupying some discrete positions of a set of discrete positions of a two-dimensional space, wherein the apparatus comprises at least one processor configured to perform the method of claim 2. ### Claim 12 (depends on 1) A non-transitory computer-readable storage medium carrying instructions of program code for executing the method of claim 1. ### Claim 13 (depends on 2) A non-transitory computer-readable storage medium carrying instructions of program code for executing the method of claim 2. ### Claim 14 (depends on 2) The method of claim 2, wherein entropy decoding the binary data (fj) is based on the sensing number (Nsens(sj,λj)) in response to the sensing number (Nsens(sj, λj) being greater than an activation threshold (thactivation); or based on at least a coordinate difference (Cj) between one first coordinate associated with the current coarse point (Pj) and one first coordinate of a preceding encoded or decoded coarse point (Pprec) with a same sensor index as a sensor index (λj) associated with the current coarse point, in response to the sensing number (Nsens(sj,λj)) not being greater than the activation threshold (thactivation). ### Claim 15 (depends on 2) The method of claim 2, wherein entropy decoding the binary data (fj) is based on a value (Δj) depending on a sample index (sj), another sample index (slast) associated with a sensing time instant at which a point of the point cloud, represented by a last occupied coarse point (Plast), has been sensed by the sensor associated with the sensor index (λj), and the sensing number (Nsens(sj,λj)). ### Claim 16 (depends on 15) The method of claim 15, wherein the value (Δj) is bounded by two thresholds. ### Claim 17 (depends on 2) The method of claim 2, wherein the sensing number (Nsens(sj,λj)) depends on at least one of a radius (robject) or an azimuthal angle (Plast) associated with a last occupied coarse point (Plast) representing a point of the point cloud sensed by the sensor (λj) associated with the current coarse point (Pj). ### Claim 18 (depends on 2) The method of claim 2, wherein the sensing number (Nsens(sj,λj)) depends on a point cloud characteristic distance (LPC), defining a mean distance between points of the point cloud, and on an arc length (Larc) defined in a two-dimensional cartesian coordinate plane between two consecutive sensing by the sensor associated with the current coarse point. ### Claim 19 (depends on 18) The method of claim 18, wherein the arc length (Larc) is based on a radius associated with a last occupied coarse point (Plast) representing a point of the point cloud sensed by the sensor associated with the current coarse point and an azimuthal shift between two consecutive sensing. ### Claim 20 (depends on 18) The method of claim 18, wherein the point cloud characteristic distance (LPC) is encoded into the bitstream.