# US 12,223,683 B2 · Method for encoding depth values of a set of 3D points once orthogonally projected into at least one image region of a projection plane > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,223,683 B2 - Document ID: US12223683B2 - Status: Granted - Kind: B2 - Application number: 18/225,704 - Filed: 2023-07-25 - Published: 2024-01-04 - Granted: 2025-02-11 - Earliest claimed: 2018-04-11 - Assignees: InterDigital VC Holdings, Inc. - Applicants: InterDigital VC Holdings, Inc. - Inventors: Julien Ricard; Celine Guede; Yannick Olivier; Joan Llach Pinsach - Web page: https://patentgrep.com/patent/US12223683B2 ## CPC - G06T 9/001: {Model-based coding, e.g. wire frame} - H04N 19/597: specially adapted for multi-view video sequence encoding - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract At least one embodiment relates to a method comprising encoding a projection mode associated with an image region of a first depth image, said projection mode indicating if said image region stores either the minimum or the maximum depth value of at least one orthogonally projected 3D point of the point cloud along a same projection direction; and encoding said depth minimum and maximum depth values as a function of said projection mode. ## Claims ### Claim 1 A method comprising: decoding first image data storing at least one first depth value of a first 3D point of a point cloud, the first 3D point and a second 3D point being orthogonally projected onto a same 2D point of a projection plane, the at least one first depth value being one of a minimum depth value from the projection plane or a maximum depth value from the projection plane, and the second 3D point having a second depth value being the other of the minimum depth value and the maximum depth value; deriving from a bitstream a projection mode signaled for a patch to which the 2D point belongs, the projection mode indicating whether the at least one first depth value is the minimum depth value or the maximum depth value; and reconstructing a geometry of the point cloud based on the projection mode. ### Claim 2 (depends on 1) The method of claim 1, wherein the first 3D point and the second 3D point correspond respectively to a nearest point and a farthest point of a connected component, from an origin of a projection axis when the projection mode equals a first value, and the first 3D point and the second 3D point correspond respectively to a farthest point and a nearest point of the connected component, from an origin of the projection axis when the projection mode equals a second value. ### Claim 3 (depends on 1) The method of claim 1, wherein the projection mode indicates whether the first image data stores depth values of nearest points projected onto the projection plane or farthest points projected onto the projection plane. ### Claim 4 (depends on 1) The method of claim 1, wherein the projection mode indicates whether the first image data stores depth values of nearest points projected onto the projection plane or farthest points projected onto the projection plane, and wherein an information representative of the projection mode is signaled at a point cloud level to indicate if the projection mode may change or not. ### Claim 5 (depends on 1) A non-transitory computer-readable medium including instructions for causing one or more processors to perform the steps of the method of claim 1. ### Claim 6 (depends on 1) The method of claim 1, further comprising decoding second image data storing an information representative of the second depth value, the information representative of the second depth value being an absolute difference between the at least one first depth value and the second depth value. ### Claim 7 (depends on 6) The method of claim 6, wherein reconstructing the geometry of the point cloud comprises reconstructing the first 3D point and the second 3D point from the first image data and the second image data as a function of the projection mode. ### Claim 8 A device comprising at least one processor configured to: decode first image data storing at least one first depth value of a first 3D point of a point cloud, the first 3D point and a second 3D point being orthogonally projected onto a same 2D point of a projection plane, the at least one first depth value being one of a minimum depth value from the projection plane or a maximum depth value from the projection plane, and the second 3D point having a second depth value being the other of the minimum depth value and the maximum depth value; derive from a bitstream a projection mode signaled for a patch to which the 2D point belongs, the projection mode indicating whether the at least one first depth value is the minimum depth value or the maximum depth value; and reconstruct a geometry of the point cloud based on the projection mode. ### Claim 9 (depends on 8) The device of claim 8, wherein the first 3D point and the second 3D point correspond respectively to a nearest point and a farthest point of a connected component, from an origin of a projection axis when the projection mode equals a first value, and the first 3D point and the second 3D point correspond respectively to a farthest point and a nearest point of the connected component, from an origin of the projection axis when the projection mode equals a second value. ### Claim 10 (depends on 8) The device of claim 8, wherein the projection mode indicates whether the first image data stores depth values of nearest points projected onto the projection plane or farthest points projected onto the projection plane. ### Claim 11 (depends on 8) The device of claim 8, wherein the projection mode indicates whether the first image data stores depth values of nearest points projected onto the projection plane or farthest points projected onto the projection plane, and wherein an information representative of the projection mode is signaled at a point cloud level to indicate if the projection mode may change or not. ### Claim 12 A method comprising: encoding first image data comprising at least one first depth value of a first 3D point of a point cloud, the first 3D point and a second 3D point being orthogonally projected onto a same 2D point of a projection plane, the at least one first depth value being one of a minimum depth value from the projection plane or a maximum depth value from the projection plane, and the second 3D point having a second depth value being the other of the minimum depth value and the maximum depth value; and signaling, in a bitstream, a projection mode for a patch to which the 2D point belongs, the projection mode indicating whether the at least one first depth value is the minimum depth value or the maximum depth value. ### Claim 13 (depends on 12) The method of claim 12, wherein the projection mode indicates whether the first image data stores depth values of nearest points projected onto the projection plane or farthest points projected onto the projection plane, and wherein an information representative of the projection mode is signaled at a point cloud level to indicate if the projection mode may change or not. ### Claim 14 (depends on 12) The method of claim 12, wherein the projection mode is signaled at a patch level if the projection mode is signaled at the point cloud level as changing. ### Claim 15 (depends on 12) A non-transitory computer-readable medium including instructions for causing one or more processors to perform the steps of the method of claim 12. ### Claim 16 (depends on 15) The non-transitory computer-readable medium of claim 15, wherein the projection mode indicates whether the first image data stores depth values of nearest points projected onto the projection plane or farthest points projected onto the projection plane. ### Claim 17 (depends on 12) The method of claim 12, further comprising encoding second image data storing an information representative of the second depth value, the information representative of the second depth value being an absolute difference between the at least one first depth value and the second depth value. ### Claim 18 A device comprising at least one processor configured to: encode first image data comprising at least one first depth value of a first 3D point of a point cloud, the first 3D point and a second 3D point being orthogonally projected onto a same 2D point of a projection plane, the at least one first depth value being one of a minimum depth value from the projection plane or a maximum depth value from the projection plane, and the second 3D point having a second depth value being the other of the minimum depth value and the maximum depth value; and signal, in a bitstream, a projection mode for a patch to which the 2D point belongs, the projection mode indicating whether the at least one first depth value is the minimum depth value or the maximum depth value. ### Claim 19 (depends on 18) The device of claim 18, wherein the first 3D point and the second 3D point correspond respectively to a nearest point and a farthest point of a connected component, from an origin of a projection axis when the projection mode equals a first value, and the first 3D point and the second 3D point correspond respectively to a farthest point and a nearest point of the connected component, from an origin of the projection axis when the projection mode equals a second value. ### Claim 20 (depends on 18) The device of claim 18, wherein the projection mode indicates whether the first image data stores depth values of nearest points projected onto the projection plane or farthest points projected onto the projection plane. ### Claim 21 (depends on 18) The device of claim 18, wherein the at least one processor is further configured to: encode second image data storing an information representative of the second depth value, the information representative of the second depth value being an absolute difference between the at least one first depth value and the second depth value.