Method and apparatus for encoding/decoding point cloud coordinate transformation residual

Patent metadata

Field	Value
Publication number	US-12445647-B2
Application number	US-202218265850-A
Country	US
Kind code	B2
Filing date	May 18, 2022
Priority date	May 26, 2021
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

An encoding method includes: obtaining original point cloud data; transforming coordinates of the original point cloud data to obtain a coordinate transformation residual; establishing a relationship between azimuth information of a point cloud and the coordinate transformation residual; determining an encoding rule for the coordinate transformation residual based on the relationship between the azimuth information of the point cloud and the coordinate transformation residual; and encoding the coordinate transformation residual according to the encoding rule, to obtain data rate information.

First claim

What is claimed is:

1. A method for encoding a point cloud coordinate transformation residual, comprising:
obtaining original point cloud data;
transforming coordinates of the original point cloud data to obtain a coordinate transformation residual;
establishing a relationship between azimuth information of a point cloud and the coordinate transformation residual, wherein establishing the relationship between the azimuth information of the point cloud and the coordinate transformation residual comprises:
establishing function expressions between the azimuth information of the point cloud and the coordinate transformation residual as follows:

Δ
⁢
x

=

r
·
cos

⁢

(
φ
)

-

(

r
+

Δ
⁢
r

)

·
cos

⁢

(

φ
+
Δφ

)

,
and

Δ
⁢
y

=

r
·
sin

⁢

(
φ
)

-

(

r
+

Δ
⁢
r

)

·
sin

⁢

(

φ
+
Δφ

)

;

wherein Δx and Δy represent coordinate transformation residual components of a point, r represents depth information of the point, φ represents azimuth information of the point, Δr represents a precision loss of the depth information of the point, and Δφ represents a precision loss of the azimuth information of the point;
determining an encoding rule for the coordinate transformation residual based on the relationship between the azimuth information of the point cloud and the coordinate transformation residual; and
encoding the coordinate transformation residual according to the encoding rule, to obtain data rate information.

2. The method for encoding a point cloud coordinate transformation residual according to claim 1 , wherein the function expressions between the azimuth information of the point cloud and the coordinate transformation residual are approximated as follows:

Δ
⁢
x

≈

-
Δ

⁢

r
·
cos

⁢

(
φ
)

,
and

Δ
⁢
y

≈

-
Δ

⁢

r
·
sin

⁢

(
φ
)

;

wherein Δx and Δy represent coordinate transformation residual components of a point, φ represents azimuth information of the point, and Δr represents a precision loss of depth information of the point.

3. The method for encoding a point cloud coordinate transformation residual according to claim 1 , wherein establishing the relationship between the azimuth information of the point cloud and the coordinate transformation residual further comprises:
obtaining a specific representation form of an angle value of an azimuth, a function value of an azimuth, or an azimuth symbol based on a function expression of the azimuth information of the point cloud and the coordinate transformation residual.

4. The method for encoding a point cloud coordinate transformation residual according to claim 1 , wherein determining the encoding rule for the coordinate transformation residual based on the relationship between the azimuth information of the point cloud and the coordinate transformation residual comprises:
dividing an azimuth into several intervals based on the relationship between the azimuth information of the point cloud and the coordinate transformation residual; and
setting a corresponding encoding rule for the coordinate transformation residual for each azimuth interval.

5. The method for encoding a point cloud coordinate transformation residual according to claim 4 , wherein setting the corresponding encoding rule for the coordinate transformation residual for each azimuth interval comprises:
separately assigning a context model for a coordinate transformation residual of each azimuth interval, and performing corresponding initialization for entropy encoding of the coordinate transformation residual of each azimuth interval.

6. The method for encoding a point cloud coordinate transformation residual according to claim 5 , wherein encoding the coordinate transformation residual according to the encoding rule comprises:
obtaining azimuth information of a current point, and determining an azimuth interval to which

Assignees

• Honor Device Co Ltd

Inventors

• Zhang Wei
• Yang Fuzheng
• Chen Tian
• Zou Wenjie

Classifications

• H04N19/91

  Entropy coding, e.g. variable length coding [VLC] or arithmetic coding · CPC title

• H04N19/597

  specially adapted for multi-view video sequence encoding · CPC title

• H04N19/149

  by estimating the code amount by means of a model, e.g. mathematical model or statistical model · CPC title

• H04N19/139

  Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability · CPC title

• H04N19/13

  Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC] · CPC title