WO2024007144A1

WO2024007144A1 - Encoding method, decoding method, code stream, encoders, decoders and storage medium

Info

Publication number: WO2024007144A1
Application number: PCT/CN2022/103817
Authority: WO
Inventors: 魏红莲
Original assignee: Oppo广东移动通信有限公司
Priority date: 2022-07-05
Filing date: 2022-07-05
Publication date: 2024-01-11

Abstract

Disclosed in the embodiments of the present application are an encoding method, a decoding method, a code stream, encoders, decoders and a storage medium. The decoding method comprises: parsing a code stream, and determining the absolute value of a quantized residual of the current point; when the absolute value of the quantized residual meets a first preset condition, determining a sign of the quantized residual of the current point according to the parity characteristic of the absolute value of the quantized residual; and determining a reconstructed value of the attribute of the current point according to the absolute value of the quantized residual and the sign. Thus, a sign is hidden on the basis of the parity characteristic of an absolute value of a quantized residual, such that the number of codewords used when encoding attribute information can be reduced, and the encoding and decoding efficiency can be improved.

Description

Coding and decoding methods, code streams, encoders, decoders and storage media

Technical field

The embodiments of the present application relate to the field of point cloud compression technology, and in particular, to a coding and decoding method, a code stream, an encoder, a decoder, and a storage medium.

Background technique

In the point cloud compression (Audio Video Standard-Point Cloud Compression, AVS-PCC) encoding and decoding framework provided based on the audio and video coding standard, the geometric information and attribute information of the point cloud are encoded separately. After the geometric encoding is completed, the geometric information is reconstructed, and the encoding of attribute information will depend on the reconstructed geometric information. Among them, attribute information encoding is mainly aimed at encoding color information, converting it into a YUV color space that is more in line with human visual characteristics, and then performing attribute encoding on the preprocessed attribute information, and finally generating a binary attribute code stream.

Currently, in the attribute encoding process of the Point Cloud Compression Reference Platform (Point Cloud Reference Model, PCRM), for points in the point cloud, the obtained attribute residual value can be either positive or negative. When encoding the attribute residual value, the sign identification information is encoded together with the attribute residual value; and the encoding of the sign identification information also requires the use of codewords, thus reducing the encoding and decoding efficiency.

Contents of the invention

Embodiments of the present application provide a coding and decoding method, a code stream, an encoder, a decoder, and a storage medium, which can reduce the number of codewords used when encoding attribute information, thereby improving coding and decoding efficiency.

The technical solutions of the embodiments of this application can be implemented as follows:

In the first aspect, embodiments of the present application provide a decoding method, which is applied to a decoder. The method includes:

Analyze the code stream and determine the absolute value of the quantized residual at the current point;

When the absolute value of the quantized residual satisfies the first preset condition, determine the sign of the quantized residual at the current point according to the parity characteristics of the absolute value of the quantized residual;

According to the absolute value and sign of the quantized residual, the attribute reconstruction value of the current point is determined.

In the second aspect, embodiments of the present application provide an encoding method, which is applied to an encoder. The method includes:

Determine the absolute value of the initial quantized residual at the current point and the sign of the initial quantized residual at the current point;

When the absolute value of the initial quantized residual satisfies the first preset condition, determine the absolute value of the quantized residual at the current point based on the sign and the parity characteristics of the absolute value of the initial quantized residual;

Encode the absolute value of the quantization residual and write the resulting coded bits into the code stream.

In the third aspect, embodiments of the present application provide a code stream. The code stream is generated by bit encoding based on the information to be encoded. The information to be encoded at least includes: the absolute value of the quantized residual of the current point, or the absolute value of the quantized residual of the current point. The absolute value of the quantized residual and the corresponding symbol identification information.

In a fourth aspect, embodiments of the present application provide an encoder, which includes a first determination unit and a coding unit; wherein,

A first determination unit configured to determine the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point; and when the absolute value of the initial quantized residual satisfies the first preset condition, according to the sign and the initial Quantize the parity characteristics of the absolute value of the residual and determine the absolute value of the quantized residual at the current point;

The encoding unit is configured to encode the absolute value of the quantization residual and write the resulting encoded bits into the code stream.

In a fifth aspect, embodiments of the present application provide an encoder, which includes a first memory and a first processor; wherein,

a first memory for storing a computer program capable of running on the first processor;

The first processor is configured to perform the method described in the first aspect when running the computer program.

In a sixth aspect, embodiments of the present application provide a decoder, which includes a decoding unit and a second determination unit; wherein,

The decoding unit is configured to parse the code stream and determine the absolute value of the quantized residual at the current point;

The second determination unit is configured to determine the sign of the quantized residual at the current point according to the parity characteristics of the absolute value of the quantized residual when the absolute value of the quantized residual satisfies the first preset condition; and based on the absolute value of the quantized residual and symbols, determine the attribute reconstruction value of the current point.

In a seventh aspect, embodiments of the present application provide a decoder, which includes a second memory and a second processor; wherein,

a second memory for storing a computer program capable of running on the second processor;

The second processor is configured to perform the method described in the second aspect when running the computer program.

In an eighth aspect, embodiments of the present application provide a computer-readable storage medium that stores a computer program. When the computer program is executed, the method as described in the first aspect, or the second aspect is implemented. methods described in this regard.

Embodiments of the present application provide a coding and decoding method, a code stream, an encoder, a decoder, and a storage medium. At the coding end, the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point are determined; When the absolute value of the initial quantized residual meets the first preset condition, the absolute value of the quantized residual at the current point is determined based on the sign and the parity characteristics of the initial quantized residual absolute value; the absolute value of the quantized residual is encoded, and all The resulting coded bits are written into the code stream. At the decoding end, the code stream is parsed to determine the absolute value of the quantized residual at the current point; when the absolute value of the quantized residual meets the first preset condition, the quantized residual at the current point is determined based on the parity characteristics of the absolute value of the quantized residual. The sign of the difference; determine the attribute reconstruction value of the current point based on the absolute value and sign of the quantized residual. In this way, on the encoding side, the parity characteristics based on the absolute value of the quantized residual can hide some symbols of the values to be encoded, that is, there is no need to encode these symbols, so as to reduce the codewords used when encoding attribute information; while on the decoding side, The corresponding symbol can be directly determined based on the parity and even characteristics of the absolute value of the quantized residual obtained by decoding; thus, the use of codewords can be reduced, the encoding and decoding efficiency of point cloud attributes can be improved, and the encoding and decoding performance of point cloud attributes can be improved.

Description of the drawings

Figure 1A is a schematic diagram of a three-dimensional point cloud image provided by an embodiment of the present application;

Figure 1B is a partially enlarged schematic diagram of a three-dimensional point cloud image provided by an embodiment of the present application;

Figure 2A is a schematic diagram of point cloud images at different viewing angles provided by an embodiment of the present application;

Figure 2B is a schematic diagram of the data storage format corresponding to Figure 2A provided by an embodiment of the present application;

Figure 3 is a schematic diagram of a point cloud encoding and decoding network architecture provided by an embodiment of the present application;

Figure 4 is a schematic structural diagram of a point cloud encoder provided by an embodiment of the present application;

Figure 5 is a schematic structural diagram of a point cloud decoder provided by an embodiment of the present application;

Figure 6 is a schematic flow chart of a decoding method provided by an embodiment of the present application;

Figure 7 is a detailed flow chart of a decoding method provided by an embodiment of the present application;

Figure 8 is a schematic flow chart of an encoding method provided by an embodiment of the present application;

Figure 9 is a detailed flow chart of an encoding method provided by an embodiment of the present application;

Figure 10 is a schematic structural diagram of an encoder provided by an embodiment of the present application;

Figure 11 is a schematic diagram of the specific hardware structure of an encoder provided by an embodiment of the present application;

Figure 12 is a schematic structural diagram of a decoder provided by an embodiment of the present application;

Figure 13 is a schematic diagram of the specific hardware structure of a decoder provided by an embodiment of the present application;

Figure 14 is a schematic structural diagram of a coding and decoding system provided by an embodiment of the present application.

Detailed ways

In order to understand the characteristics and technical content of the embodiments of the present application in more detail, the implementation of the embodiments of the present application will be described in detail below with reference to the accompanying drawings. The attached drawings are for reference only and are not intended to limit the embodiments of the present application.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

In the following description, reference is made to "some embodiments" which describe a subset of all possible embodiments, but it is understood that "some embodiments" may be the same subset or a different subset of all possible embodiments, and Can be combined with each other without conflict.

It should also be pointed out that the terms "first\second\third" involved in the embodiments of this application are only used to distinguish similar objects and do not represent a specific ordering of objects. It is understandable that "first\second\ The third "specific order or sequence may be interchanged where permitted, so that the embodiments of the application described herein can be implemented in an order other than that illustrated or described herein.

Point Cloud is a three-dimensional representation of the surface of an object. Through collection equipment such as photoelectric radar, lidar, laser scanner, and multi-view camera, the point cloud (data) of the surface of the object can be collected.

Point cloud is a set of discrete points randomly distributed in space that expresses the spatial structure and surface properties of a three-dimensional object or scene. Figure 1A shows a three-dimensional point cloud image and Figure 1B shows a partial enlargement of the three-dimensional point cloud image. It can be seen that the point cloud surface is composed of densely distributed points.

Two-dimensional images have information expressed in each pixel and are distributed regularly, so there is no need to record additional position information; however, the distribution of points in the point cloud in the three-dimensional space is random and irregular, so each point needs to be recorded Only the position of the point in space can completely express a point cloud. Similar to two-dimensional images, each position in the collection process has corresponding attribute information, usually RGB color values, and the color values reflect the color of the object; for point clouds, the attribute information corresponding to each point is in addition to color information. , and the more common one is the reflectance value, which reflects the surface material of the object. Therefore, points in the point cloud can include point location information and point attribute information. For example, the position information of the point may be the three-dimensional coordinate information (x, y, z) of the point. The position information of a point can also be called the geometric information of the point. For example, the attribute information of a point may include color information (three-dimensional color information) and/or reflectance (one-dimensional reflectance information r), and so on. For example, color information can be information on any color space. For example, the color information may be RGB information. Among them, R represents red (Red, R), G represents green (Green, G), and B represents blue (Blue, B). For another example, the color information may be brightness and chrominance (YCbCr, YUV) information. Among them, Y represents brightness (Luma), Cb(U) represents blue color difference, and Cr(V) represents red color difference.

According to the point cloud obtained based on the principle of laser measurement, the points in the point cloud can include the three-dimensional coordinate information of the point and the reflectivity value of the point. For another example, in a point cloud obtained according to the principle of photogrammetry, the points in the point cloud may include the three-dimensional coordinate information of the point and the three-dimensional color information of the point. For another example, a point cloud is obtained by combining the principles of laser measurement and photogrammetry. The points in the point cloud may include the three-dimensional coordinate information of the point, the reflectivity value of the point, and the three-dimensional color information of the point.

Figure 2A and Figure 2B show a point cloud image and its corresponding data storage format. Among them, Figure 2A provides six viewing angles of the point cloud image. Figure 2B is composed of the file header information part and the data part. The header information includes the data format, data representation type, total number of point cloud points, and the content represented by the point cloud. . For example, the point cloud is in ".ply" format and is represented by ASCII code. The total number of points is 207242. Each point has three-dimensional coordinate information (x, y, z) and three-dimensional color information (r, g, b).

Point clouds can be divided into:

Static point cloud: that is, the object is stationary and the device that obtains the point cloud is also stationary;

Dynamic point cloud: The object is moving, but the device that obtains the point cloud is stationary;

Dynamically acquire point clouds: The device that acquires point clouds is in motion.

For example, point clouds are divided into two categories according to their uses:

Category 1: Machine perception point cloud, which can be used in scenarios such as autonomous navigation systems, real-time inspection systems, geographic information systems, visual sorting robots, and rescue and disaster relief robots;

Category 2: Human eye perception point cloud, which can be used in point cloud application scenarios such as digital cultural heritage, free-viewpoint broadcasting, three-dimensional immersive communication, and three-dimensional immersive interaction.

Point clouds can flexibly and conveniently express the spatial structure and surface properties of three-dimensional objects or scenes, and because point clouds are obtained by directly sampling real objects, they can provide a strong sense of reality while ensuring accuracy, so they are widely used and their scope Including virtual reality games, computer-aided design, geographic information systems, automatic navigation systems, digital cultural heritage, free-viewpoint broadcasting, three-dimensional immersive telepresence, three-dimensional reconstruction of biological tissues and organs, etc.

Point cloud collection mainly has the following methods: computer generation, 3D laser scanning, 3D photogrammetry, etc. Computers can generate point clouds of virtual three-dimensional objects and scenes; 3D laser scanning can obtain point clouds of static real-world three-dimensional objects or scenes, and can obtain millions of point clouds per second; 3D photogrammetry can obtain dynamic real-world three-dimensional objects or scenes Point clouds can obtain tens of millions of point clouds per second. These technologies reduce the cost and time period of point cloud data acquisition and improve the accuracy of the data. Changes in the way of obtaining point cloud data have made it possible to obtain large amounts of point cloud data. With the growth of application requirements, the processing of massive 3D point cloud data has encountered bottlenecks limited by storage space and transmission bandwidth.

For example, taking a point cloud video with a frame rate of 30 frames per second (fps), the number of points in each frame of the point cloud is 700,000, and each point has coordinate information xyz (float) and color information RGB (uchar), Then the data volume of 10s point cloud video is approximately 0.7 million×(4Byte×3+1Byte×3)×30fps×10s=3.15GB, where 1Byte is 10bit, and the YUV sampling format is 4:2:0, and the frame rate The data volume of 1280×720 2D video at 24fps for 10s is about 1280×720×12bit×24fps×10s≈0.33GB, and the data volume of two-view 3D video for 10s is about 0.33×2=0.66GB. It can be seen that the data volume of point cloud video far exceeds the data volume of 2D video and 3D video of the same length. Therefore, in order to better realize data management, save server storage space, and reduce transmission traffic and transmission time between the server and the client, point cloud compression has become a key issue to promote the development of the point cloud industry.

In other words, since the point cloud is a collection of massive points, storing the point cloud will not only consume a lot of memory, but is also not conducive to transmission. There is not such a large bandwidth to support the direct transmission of the point cloud at the network layer without compression. Therefore, , the point cloud needs to be compressed.

Currently, the point cloud coding framework that can compress point clouds can be the Geometry-based Point Cloud Compression (G-PCC) codec framework provided by the Moving Picture Experts Group (MPEG) Or the Video-based Point Cloud Compression (V-PCC) codec framework, or the AVS-PCC codec framework provided by AVS. The G-PCC encoding and decoding framework can be used to compress the first type of static point cloud and the third type of dynamic point cloud, and the V-PCC encoding and decoding framework can be used to compress the second type of dynamic point cloud. The G-PCC encoding and decoding framework is also called point cloud codec TMC13, and the V-PCC encoding and decoding framework is also called point cloud codec TMC2.

This embodiment of the present application provides a network architecture of a point cloud encoding and decoding system that includes a decoding method and an encoding method. Figure 3 is a schematic diagram of the network architecture of a point cloud encoding and decoding system provided by an embodiment of the present application. As shown in FIG. 3 , the network architecture includes one or more electronic devices 13 to 1N and a communication network 01 , wherein the electronic devices 13 to 1N can perform video interaction through the communication network 01 . During the implementation process, electronic devices may be various types of devices with point cloud encoding and decoding functions. For example, the electronic devices may include mobile phones, tablet computers, personal computers, personal digital assistants, navigators, digital phones, and video phones. , televisions, sensing equipment, servers, etc., are not limited by the embodiments of this application. Among them, the decoder or encoder in the embodiment of the present application can be the above-mentioned electronic device.

Among them, the electronic device in the embodiment of the present application has a point cloud encoding and decoding function, and generally includes a point cloud encoder (ie, encoder) and a point cloud decoder (ie, decoder).

The following uses the AVS-PCC encoding and decoding framework as an example to illustrate the point cloud compression technology.

It can be understood that point cloud compression generally adopts the method of compressing point cloud geometric information and attribute information separately. On the encoding side, the point cloud geometric information is first encoded in the geometry encoder, and then the reconstructed geometric information is input into the attribute encoder as additional information. , assists in the compression of point cloud attributes; on the decoding end, the point cloud geometric information is first decoded in the geometry decoder, and then the decoded geometric information is input into the attribute decoder as additional information to assist in the compression of point cloud attributes. The entire codec consists of pre-processing/post-processing, geometry encoding/decoding, and attribute encoding/decoding.

The embodiment of the present application provides a point cloud encoder. Figure 4 shows the framework of the point cloud compression reference platform PCRM provided by AVS. The point cloud encoder 11 includes a geometric encoder: a coordinate translation unit 111 and a coordinate quantization unit. 112. Octree construction unit 113, geometric entropy encoder 114, geometric reconstruction unit 115. Attribute encoder: attribute recoloring unit 116, color space transform unit 117, first attribute prediction unit 118, quantization unit 119 and attribute entropy encoder 1110.

For PCRM, in the geometric encoding part of the coding end, the original geometric information is first preprocessed, the geometric origin is normalized to the minimum position in the point cloud space through the coordinate translation unit 111, and the geometric information is transferred from the float to the point cloud space through the coordinate quantization unit 112. The points are converted into shapes to facilitate subsequent regularization processing; then the regularized geometric information is geometrically encoded, and the octree structure is used in the octree construction unit 113 to recursively divide the point cloud space, dividing the current point each time into eight sub-blocks of the same size, and determine the occupied codeword status of each sub-block. When the sub-block does not contain points, it is recorded as empty, otherwise it is recorded as non-empty. The occupancy of all blocks is recorded at the last level of recursive division. The codeword information is geometrically encoded; on the one hand, the geometric information expressed through the octree structure is input to the geometric entropy encoder 114 to form a geometric code stream; on the other hand, the geometric reconstruction process is performed in the geometric reconstruction unit 115. The reconstructed geometry The information is input to the attribute encoder as additional information.

In the attribute encoding part, the original attribute information is first preprocessed. Since the geometric information changes after the geometric encoding, the attribute value is reassigned to each point after the geometric encoding through the attribute recoloring unit 116 to realize the attribute Repaint. In addition, if the attribute information being processed is color information, the original color information needs to be transformed into a color space through the color space transformation unit 117 to convert it into a YUV color space that is more in line with the visual characteristics of the human eye; and then predicted through the first attribute Unit 118 performs attribute encoding on the preprocessed attribute information. At first, the point cloud needs to be reordered. The reordering method is Morton code, so the traversal order of attribute encoding is Morton order. The attribute prediction method in PCRM is a single point prediction based on Morton order, that is, going back one point from the current point to be encoded (current point) according to Morton order, and the node found is the prediction reference point of the current point to be encoded, and then The attribute reconstruction value of the prediction reference point is used as the attribute prediction value, and the attribute residual value is the difference between the attribute original value and the attribute prediction value of the current point to be encoded; finally, the attribute residual value is quantized through the quantization unit 119, and The quantized residual information is input to the attribute entropy encoder 1110 to form an attribute code stream.

The embodiment of the present application also provides a point cloud decoder. Figure 5 shows the framework of the point cloud compression reference platform PCRM provided by AVS. The point cloud decoder 12 includes a geometric decoder: a geometric entropy decoder 121, Octree reconstruction unit 122, coordinate inverse quantization unit 123, and coordinate inverse translation unit 124. Attribute decoder: attribute entropy decoder 125, inverse quantization unit 126, second attribute prediction unit 127 and color space inverse transform unit 128.

On the decoding end, geometry and attributes are also decoded separately. In the geometry decoding part, the geometry code stream is first entropy decoded through the geometric entropy decoder 121 to obtain the geometric information of each node, and then the octree structure is constructed through the octree reconstruction unit 122 in the same way as the geometry encoding, combined with The decoded geometry reconstructs the geometric information expressed through the octree structure after coordinate transformation. On the one hand, the information is coordinate inverse quantized through the coordinate inverse quantization unit 123 and inversely translated through the coordinate inverse translation unit 124 to obtain the decoded geometry information. On the other hand, it is input to the attribute decoder as additional information. In the attribute decoding part, the Morton order is constructed in the same way as the encoding end. First, the attribute code stream is entropy decoded through the attribute entropy decoder 125 to obtain the quantized residual information; then inverse quantization is performed through the inverse quantization unit 126. Obtain the attribute residual value; similarly, in the same manner as attribute encoding, obtain the attribute prediction value of the current to-be-decoded point through the second attribute prediction unit 127, and then add the attribute prediction value and the attribute residual value to recover The attribute reconstruction value of the current point to be decoded (for example, YUV attribute value); finally, the decoding attribute information is obtained through the inverse color space transformation of the color space inverse transformation unit 128 .

It can also be understood that for the AVS-PCC encoding and decoding framework, the general test conditions are as follows:

(1) There are 4 types of test conditions:

Condition 1: The geometric position is limited and lossy, and the attributes are lossy;

Condition 2: The geometric position is lossless and the attributes are lossy;

Condition 3: The geometric position is lossless, and the attributes are limited and lossy;

Condition 4: The geometric position is lossless and the attributes are lossless.

(2) The universal test sequence includes five categories: Cat1A, Cat1B, Cat1C, Cat2-frame and Cat3. Among them, Cat1A and Cat2-frame point clouds only contain reflectance attribute information, Cat1B and Cat3 point clouds only contain color attribute information, and Cat1C point clouds contain both color and reflectance attribute information.

(3) Technical routes: 4 types in total, distinguished by the algorithm used for attribute compression.

Technical route 1: Prediction branch, attribute compression uses a method based on intra-frame prediction:

On the encoding side, the points in the point cloud are processed in a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.). The prediction algorithm is first used to obtain the attribute prediction value, and the attribute prediction value is obtained based on the attribute value and attribute prediction. The attribute residuals are obtained from the values, and then the attribute residuals are quantized to generate quantized residuals, and finally the quantized residuals are encoded;

On the decoding end, the points in the point cloud are processed in a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.). The prediction algorithm is first used to obtain the attribute prediction value, and then the decoding is performed to obtain the quantized residual. , then perform inverse quantization on the quantized residual, and finally obtain the attribute reconstruction value based on the attribute prediction value and the inverse-quantized attribute residual.

Technical route 2: Predictive transformation branch - resources are limited. Attribute compression uses methods based on intra-frame prediction and discrete cosine transform (Discrete Cosine Transform, DCT). At this time, there is a maximum number of points when encoding the quantized transform coefficients. The restriction of X (such as 4096) means that at most every X point can be encoded as a group:

On the encoding side, the points in the point cloud are processed in a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.), and the entire point cloud is first divided into parts with a maximum length of Y (for example, 2) Several small groups, and then combine these small groups into several large groups (the number of points in each large group does not exceed Difference, perform DCT transformation on the attribute residuals in small groups, generate transformation coefficients, then quantize the transformation coefficients, generate quantized transformation coefficients, and finally encode the quantized transformation coefficients in large groups;

On the decoding end, the points in the point cloud are processed in a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.), and the entire point cloud is first divided into parts with a maximum length of Y (for example, 2) Several small groups, and then combine these small groups into several large groups (the number of points in each large group does not exceed The predicted value is then inversely quantized and inversely transformed on the quantized transformation coefficient in small groups. Finally, the attribute reconstruction value is obtained based on the attribute predicted value and the inversely quantized and inversely transformed coefficient.

Technical route 3: Predictive transformation branch - resources are not limited. Attribute compression uses methods based on intra-frame prediction and DCT transformation. When encoding the quantized transformation coefficients, there is no limit to the maximum number of points X at this time, that is, all coefficients Coding together:

On the encoding side, the points in the point cloud are processed in a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.), and the entire point cloud is first divided into parts with a maximum length of Y (for example, 2) Several groups are formed, and then the prediction algorithm is used to obtain the attribute prediction value, and the attribute residual is obtained based on the attribute value and the attribute prediction value. The attribute residual is DCT transformed in groups as a unit to generate the transformation coefficient, and then the transformation coefficient is quantified to generate the quantization The final transformation coefficients, and finally the quantized transformation coefficients of the entire point cloud are encoded;

On the decoding end, the points in the point cloud are processed in a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.), and the entire point cloud is first divided into parts with a maximum length of Y (for example, 2) Several groups are formed, decode and obtain the quantized transformation coefficients of the entire point cloud, and then use the prediction algorithm to obtain the attribute prediction values. Then, the quantized transformation coefficients are inversely quantized and inversely transformed in groups as a unit, and finally the attribute prediction values and inverse transformations are performed. The coefficients after quantization and inverse transformation are used to obtain attribute reconstruction values.

Technical route 4: Multi-layer transformation branch, attribute compression uses a method based on multi-layer wavelet transform:

At the encoding end, multi-layer wavelet transform is performed on the entire point cloud to generate transform coefficients, then the transform coefficients are quantized, the quantized transform coefficients are generated, and finally the quantized transform coefficients of the entire point cloud are encoded;

At the decoding end, decoding obtains the quantized transformation coefficients of the entire point cloud, and then performs inverse quantization and inverse transformation on the quantized transformation coefficients to obtain attribute reconstruction values.

In a specific embodiment, the prediction branch: processes the points in the point cloud according to a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.).

On the coding side, the specific implementation process is as follows:

a) Use the prediction algorithm to obtain the attribute prediction value Aj′;

b) Calculate the attribute residual according to the attribute value Aj and the attribute prediction value Aj′ (and the cross-component attribute prediction value residualPrevComponent). The formula is as follows,

res＝A _j -A _j ′(-residualPrevComponent) (1)

c) Quantify the absolute value of the attribute residual and generate the quantized residual resQ;

d) Encode the signed quantized residual sign*resQ.

On the decoding side, the specific implementation process is as follows:

a) Use the prediction algorithm to obtain the attribute prediction value Aj′;

b) (obtain the cross-component attribute prediction value residualPrevComponent,) decode to obtain the signed quantized residual, and then inverse quantize the quantized residual to obtain the decoded residual value;

c) Obtain the attribute reconstruction value based on the attribute prediction value and the signed decoding residual value sign*InvQ(resQ) of the cross-component attribute prediction value. The formula is as follows,

In the related art, when encoding the signed quantized residual sign*resQ, not only the quantized residual resQ but also the symbol sign needs to be encoded. Since the encoding of the symbol sign also requires the use of codewords, the codewords required for encoding attribute information are increased and the encoding and decoding efficiency is reduced.

The embodiment of the present application provides a coding and decoding method. At the encoding end, the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point are determined; the absolute value of the initial quantized residual satisfies the first preset condition. In the case of , according to the parity characteristics of the symbol and the initial quantized residual absolute value, determine the quantized residual absolute value of the current point; encode the quantized residual absolute value, and write the resulting coded bits into the code stream. At the decoding end, the code stream is parsed to determine the absolute value of the quantized residual at the current point; when the absolute value of the quantized residual meets the first preset condition, the quantized value of the current point is determined based on the parity characteristics of the absolute value of the quantized residual. The sign of the residual; determine the attribute reconstruction value of the current point based on the absolute value and sign of the quantized residual.

In this way, on the encoding side, the parity characteristics based on the absolute value of the quantized residual can hide some symbols of the values to be encoded, that is, there is no need to encode these symbols, so as to reduce the codewords used when encoding attribute information; while on the decoding side, The corresponding symbol can be directly determined based on the parity and even characteristics of the absolute value of the quantized residual obtained by decoding; thus, the use of codewords can be reduced, the encoding and decoding efficiency of point cloud attributes can be improved, and the encoding and decoding performance of point cloud attributes can be improved.

Each embodiment of the present application will be described in detail below with reference to the accompanying drawings.

In an embodiment of the present application, see FIG. 6 , which shows a schematic flowchart of a decoding method provided by an embodiment of the present application. As shown in Figure 6, the method may include:

S601: Analyze the code stream and determine the absolute value of the quantized residual at the current point.

It should be noted that the decoding method described in the embodiment of the present application specifically refers to a point cloud decoding method, and more specifically a point cloud attribute decoding method based on symbol hiding, in order to further reduce the codewords used when encoding attribute information. This method can be applied to point cloud decoders (also simply called "decoders").

It should also be noted that in this embodiment of the present application, the point cloud to be processed includes at least one point. Among them, for a point in the point cloud to be processed, when decoding the point, it can be used as a point to be decoded in the point cloud to be processed, and there are multiple decoded points around the point. Here, the current point is the point to be decoded that currently needs to be decoded among the at least one point.

Further, in the embodiment of this application, for each point in the point cloud to be processed, it corresponds to a geometric information and an attribute information; wherein, the geometric information represents the spatial relationship of the point, and the attribute information represents the attribute information of the point. .

Here, the attribute information may be a color component, or may be reflectance, refractive index, or other attributes, which are not specifically limited in the embodiments of this application. Wherein, when the attribute information is a color component, it can specifically be color information in any color space. For example, the attribute information may be color information in the RGB space, color information in the YUV space, color information in the YCbCr space, etc., which are not specifically limited in the embodiments of the present application.

In the embodiment of the present application, the color component may include at least one of the following: a first color component, a second color component, and a third color component. In this way, if the color component conforms to the RGB color space, then it can be determined that the first color component, the second color component and the third color component are respectively one of them: R component, G component, B component; if the color component conforms to the YUV color space, Then it can be determined that the first color component, the second color component and the third color component are each one of them: Y component, U component, V component; if the color component conforms to the YCbCr color space, then it can be determined that the first color component, the second color component The color component and the third color component are each one of them: Y component, Cb component, Cr component. For example, for the RGB color space, the first color component may be the R component, the second color component may be the G component, and the third color component may be the B component; or, the first color component may be the G component, and the third color component may be the G component. The second color component may be the B component, and the third color component may be the R component; or, the first color component may be the B component, the second color component may be the G component, the third color component may be the R component, etc., this application The examples are not specifically limited either.

It should also be noted that in this embodiment of the present application, the decoder can process each point in the point cloud to be processed according to a preset decoding order. In some embodiments, the preset decoding order may be: the original collection order of point clouds, Morton order or Hilbert order, etc., which is not specifically limited in the embodiments of this application.

It can be understood that for the current point, when parsing the code stream, the absolute value of the quantization residual of the current point can be directly obtained. Whether it is necessary to parse the code stream to obtain the symbol corresponding to the current point also needs to be judged based on the absolute value of the quantization residual.

S602: When the absolute value of the quantized residual satisfies the first preset condition, determine the sign of the quantized residual at the current point according to the parity characteristics of the absolute value of the quantized residual.

It should be noted that, in this embodiment of the present application, the first preset condition may be a preset judgment standard for determining whether to hide the symbol corresponding to the current point. For example, whether the absolute value of the quantized residual satisfies the first preset condition may be determined based on a comparison result between the absolute value of the quantized residual and a preset threshold. Therefore, in some embodiments, the method may further include:

If the absolute value of the quantized residual is greater than or equal to the preset threshold, it is determined that the absolute value of the quantized residual satisfies the first preset condition;

If the absolute value of the quantized residual is less than the preset threshold, it is determined that the absolute value of the quantized residual does not meet the first preset condition.

In the embodiment of the present application, the preset threshold here can also be regarded as a judgment criterion for determining whether to hide the symbol corresponding to the current point. Here, the preset threshold can be represented by signH, and the value of the preset threshold can be set to 4, 5, 6, 8, etc. For example, the value of the preset threshold is equal to 4, but this is not specifically limited. In addition, it should be noted that, for the situation where the absolute value of the initial quantized residual is equal to the preset threshold, it may be determined that the absolute value of the initial quantized residual satisfies the first preset condition, or it may be determined that the absolute value of the initial quantized residual does not The first preset condition is met, and there is no specific limitation here.

It should also be noted that when the absolute value of the quantized residual satisfies the first preset condition, the sign of the quantized residual is hidden at this time. In a possible embodiment, determining the sign of the quantized residual based on the parity characteristics of the absolute value of the quantized residual may include:

If the absolute value of the quantized residual is an odd number, the sign is determined to be negative;

If the absolute value of the quantized residual is an even number, the sign is determined to be positive.

In the embodiment of the present application, when the symbol of the quantized residual is determined to be hidden, the decoding end can determine the symbol based on the parity characteristics of the absolute value of the quantized residual. For example, if the absolute value of the quantized residual is an odd number, then the sign can be determined to be a negative sign, that is, the signed quantized residual value is a negative odd number; and/or if the absolute value of the quantized residual is an even number, then the sign can be determined is a positive sign, that is, the signed quantized residual value is a positive even number.

In another possible embodiment, determining the sign of the quantized residual at the current point based on the parity characteristics of the absolute value of the quantized residual may include:

If the absolute value of the quantized residual is an odd number, the sign is determined to be positive;

If the absolute value of the quantized residual is an even number, the sign is determined to be negative.

In the embodiment of the present application, when the symbol of the quantized residual is determined to be hidden, the decoder can still determine the symbol based on the parity characteristics of the absolute value of the quantized residual. For example, if the absolute value of the quantized residual is an odd number, then the sign can be determined to be positive, that is, the signed quantized residual value is a positive odd number; and/or if the absolute value of the quantized residual is an even number, then the sign can be determined is a negative sign, that is, the signed quantized residual value is a negative even number.

It should also be noted that in the embodiment of the present application, determining the parity characteristics of the absolute value of the quantized residual may include: calculating the parity characteristics of the absolute value of the quantized residual to obtain the parity value; if the parity value is equal to the third value, then The absolute value of the quantized residual is determined to be an odd number; and/or, if the odd-even value is equal to the fourth value, the absolute value of the quantized residual is determined to be an even number.

Here, the value of the third value is equal to 1, and the value of the fourth value is equal to 0. For example, it is assumed that the absolute value of the quantized residual is represented by resQ, and the parity value is represented by parity. Calculate the parity value of the absolute value of the quantized residual, parity=resQ%2. Among them, if parity=1, then it can be determined that the absolute value of the quantized residual is an odd number; otherwise, if parity=0, then it can be determined that the absolute value of the quantized residual is an even number.

It should also be noted that in the embodiment of the present application, if the signed quantized residual value is an odd number greater than zero, it means that the signed quantized residual value is a positive odd number; if the signed quantized residual value is greater than If it is an even number of zero, it means that the signed quantized residual value is a positive even number; if the signed quantized residual value is an odd number less than zero, it means that the signed quantized residual value is a negative odd number; if the signed quantized residual value is an odd number If the difference is an even number less than zero, it means that the signed quantized residual value is a negative even number.

In this way, when the absolute value of the quantized residual satisfies the first preset condition, the decoder can determine the sign of the quantized residual at the current point based on the parity characteristics of the absolute value of the quantized residual. However, for the case where the absolute value of the quantized residual does not meet the first preset condition, in some embodiments, the method may also include: parsing the code stream when the absolute value of the quantized residual does not meet the first preset condition. , determine the sign of the quantized residual at the current point.

That is to say, in the embodiment of this application, taking the preset threshold as an example, if the absolute value of the quantized residual is less than the preset threshold, that is, the absolute value of the quantized residual does not meet the first preset condition, it means that the symbol will be written into the code stream, so that the decoder can obtain the symbol of the quantized residual through decoding.

In a specific embodiment, analyzing the code stream and determining the sign of the quantized residual at the current point may include:

Parse the code stream and obtain the value of the symbol identification information;

If the value of the symbol identification information is the first value, it is determined that the symbol is a positive sign;

If the value of the symbol identification information is the second value, it is determined that the symbol is a negative sign.

It should be noted that in this embodiment of the present application, the first value may be 1 and the second value may be 0; or, the first value may be 0 and the second value may be 1, without any limitation here.

It should also be noted that in the embodiment of the present application, for symbols (positive signs or negative signs), the encoding end writes the symbols into the code stream according to the value of the symbol identification information. In this way, the decoding end can obtain the value of the symbol identification information by parsing the code stream; and then determine whether the symbol is a positive sign or a negative sign based on the value of the symbol identification information. For example, assuming that the first value is 1 and the second value is 0, then when the value of the symbol identification information obtained by decoding is 1, it can be determined that the symbol is a positive sign; when the value of the symbol identification information obtained by decoding is When 0, the sign can be determined to be negative.

S603: Determine the attribute reconstruction value of the current point based on the absolute value and sign of the quantized residual.

It should be noted that before determining the attribute reconstruction value of the current point, the method may also include: predicting the attribute information of the current point and determining the attribute prediction value of the current point.

In the embodiment of this application, a prediction algorithm is used to perform prediction processing on the attribute information of the current point, and the attribute prediction value of the current point can be obtained, which is represented by A _j ′. Among them, j indicates that the jth point in the point cloud to be processed is the current point, and the prediction algorithm can also include an intra-frame prediction algorithm and an inter-frame prediction algorithm.

In some embodiments, after obtaining the attribute prediction value of the current point, determining the attribute reconstruction value of the current point based on the absolute value and sign of the quantized residual may include:

Perform inverse quantization processing on the absolute value of the quantized residual to obtain the decoded residual value;

Determine the signed decoding residual value based on the decoding residual value and sign;

Based on the attribute prediction value and the signed decoding residual value, the attribute reconstruction value of the current point is determined.

It should be noted that at the decoding end, the absolute value of the quantized residual needs to be inversely quantized first to obtain the decoded residual value, which can be represented by InvQ (resQ); then the signed decoding is determined based on the decoded residual value and symbol. The residual value can be represented by sign*InvQ(resQ); in this way, based on the attribute prediction value and the signed decoded residual value, the attribute reconstruction value of the current point can be determined. You can use

express.

In a possible embodiment, determining the attribute reconstruction value of the current point based on the attribute prediction value and the signed decoding residual value may include: performing an addition operation on the attribute prediction value and the signed decoding residual value. , get the attribute reconstruction value of the current point.

That is to say, by adding the attribute prediction value and the signed decoding residual value, the attribute reconstruction value of the current point can be obtained. For example, the calculation formula is as follows,

Further, if the attribute information is a color component, the color component may include at least one of the following: a first color component, a second color component, and a third color component. Since there is a correlation between different color components, for the color components, the cross-component attribute prediction value can also be included, represented by residualPrevComponent. Therefore, in some embodiments, the method may further include: when the attribute information is a color component, determining a cross-component attribute prediction value of the current point. Here, it should be noted that if the attribute information is reflectivity, refractive index, etc., since the reflectance does not include multiple components, and the refractive index does not include multiple components, then for attribute information such as reflectivity, refractive index, etc., then There will be no cross-component attribute predictions.

In another possible embodiment, when the attribute information is a color component, determining the attribute reconstruction value of the current point based on the attribute prediction value and the signed decoding residual value may include: , the signed decoding residual value and the cross-component attribute prediction value are added to obtain the attribute reconstruction value of the current point.

That is to say, by adding the attribute prediction value, the cross-component attribute prediction value and the signed decoding residual value, the attribute reconstruction value of the current point can be obtained. For example, the calculation formula is as follows,

To put it simply, in the embodiment of the present application, in order to reduce the number of codewords required when encoding attribute information, the parity characteristics according to the absolute value of the quantized residual can be introduced to hide part of the symbols to be encoded; so that at the decoding end, part of the symbols to be encoded are The encoded symbols do not need to be decoded from the code stream, thus reducing the use of code words.

Embodiments of the present application provide a decoding method that determines the absolute value of the quantized residual at the current point by parsing the code stream; when the absolute value of the quantized residual satisfies the first preset condition, the absolute value of the quantized residual is determined based on the parity of the absolute value of the quantized residual. Characteristics, determine the sign of the quantized residual of the current point; determine the attribute reconstruction value of the current point based on the absolute value and sign of the quantized residual. In this way, for the situation where the absolute value of the quantized residual meets the first preset condition, the corresponding symbol can be directly determined based on the parity characteristics of the decoded absolute value of the quantized residual; thus, the use of codewords can be reduced and the encoding of point cloud attributes can be improved. Decoding efficiency, while improving the encoding and decoding performance of point cloud attributes.

In another embodiment of the present application, based on the decoding method described in the previous embodiment, see FIG. 7 , which shows a detailed flowchart of a decoding method provided by the embodiment of the present application. As shown in Figure 7, taking the preset threshold as an example, the detailed process may include:

S701: Analyze the code stream and determine the absolute value of the quantized residual at the current point.

S702: Compare the absolute value of the quantized residual with the preset threshold.

S703: Analyze the code stream and determine the sign of the quantized residual at the current point.

S704: If the absolute value of the quantized residual is an odd number, the sign is negative; and/or, if the absolute value of the quantized residual is an even number, the sign is positive.

S705: Perform inverse quantization processing on the absolute value of the quantized residual to obtain a decoded residual value; and determine a signed decoded residual value based on the decoded residual value and sign.

S706: Determine the attribute prediction value of the current point, and determine the attribute reconstruction value of the current point based on the attribute prediction value and the signed decoding residual value.

It should be noted that in this embodiment of the present application, for S702, after comparing the absolute value of the quantized residual with the preset threshold, if the absolute value of the quantized residual is greater than or equal to the preset threshold, then S704 needs to be executed, The sign is determined according to the odd and even characteristics of the absolute value of the quantized residual. For example, if the absolute value of the quantized residual is an odd number, the sign is negative; if the absolute value of the quantized residual is an even number, the sign is positive; otherwise, if If the absolute value of the quantized residual is less than the preset threshold, then S703 needs to be executed. At this time, the symbol is decoded from the code stream. For example, if the value of the symbol is the first value, it is determined that the symbol is a positive sign; if the value of the symbol is If the value is the second value, the sign is determined to be negative.

It should also be noted that in the embodiment of the present application, for the color components, the decoding process shown in Figure 7 needs to be executed once for the first color component, the second color component and the third color component respectively, and after determining the current point When reconstructing the attribute value, it is also necessary to obtain the cross-component attribute prediction value. For S706, specifically, the attribute prediction value, the signed decoding residual value and the cross-component attribute prediction value are added to obtain the attributes of the current point. Rebuild value. Here, for attribute information such as reflectivity or refractive index, the decoding process shown in Figure 7 is only executed once, and there is no need to obtain additional cross-component attribute prediction values. For S706, specifically the attribute prediction value and signed The decoded residual values are added to obtain the attribute reconstruction value of the current point.

It should also be noted that in the embodiment of the present application, for S704, in addition to if the absolute value of the quantized residual is an odd number, the sign is a negative sign; if the absolute value of the quantized residual is an even number, the sign is a positive sign. , it can also be: if the absolute value of the quantized residual is an even number, the sign is negative; if the absolute value of the quantized residual is an odd number, the sign is positive. In other words, if the sign is determined based on the parity characteristics of the absolute value of the quantized residual, there is no specific limit here.

In a specific embodiment, for the decoder, first, if the attribute information is a color component, the following steps are performed once for the three color components; if the attribute information is reflectance, the following steps are performed once for the reflectance. . The specific process is as follows:

a) Use the prediction algorithm to obtain the attribute prediction value A _j ′;

b) Decode to obtain the signed quantized residual value, including:

1) First parse the code stream and obtain the absolute value of the quantized residual;

2) Compare the absolute value of the quantized residual with the preset threshold (represented by signH, for example, it can be set to 4). If the absolute value of the quantized residual is less than signH, proceed to step 3), otherwise proceed to step 4);

3) Parse the code stream and obtain the sign of the quantized residual;

4) If the absolute value of the quantized residual is an odd number, the sign sign is negative; if the absolute value of the quantized residual is an even number, the sign sign is positive;

c) Inverse quantize the absolute value of the quantized residual to obtain the decoded residual value InvQ(resQ);

d) Obtain the attribute reconstruction value based on the attribute prediction value, the cross-component attribute prediction value, and the signed decoding residual value sign*InvQ(resQ), such as

Illustratively, taking the attribute information of reflectivity as an example, Table 1 shows a test result under the C1 test condition provided by the embodiment of the present application. Among them, the C1 test condition is limited-lossy geometry, lossy attributes (limit-lossy geometry, lossy attributes); the general test sequence is Cat1A and Cat1C; End-to-End BD-AttrRate indicates that the end-to-end attribute value is based on the attribute code Streaming BD-Rate. BD-Rate reflects the difference in the Peak Signal to Noise Ratio (PSNR) curves obtained in two situations (with or without using the technical solution of the embodiment of the present application). When BD-Rate decreases, it means that the PSNR is equal In the case of , the code rate is reduced and the performance is improved; otherwise, the performance is reduced. That is, the more the BD-Rate decreases, the better the compression effect. It can be seen from Table 1 that the BD-Rate is a negative value (that is, the BD-Rate is reduced), which means that after using the technical solution of the embodiment of the present application, the codewords can be reduced and the encoding and decoding performance can be improved.

Through the above embodiments, the specific implementation of the foregoing embodiments is elaborated in detail. According to the technical solutions of the foregoing embodiments, it can be seen that this technical solution provides a point cloud attribute encoding and decoding method based on symbol hiding. In order to further reduce The codewords required to encode attribute information can introduce symbols that hide part of the value to be encoded based on parity, so that the decoder can determine the corresponding symbol based on the parity characteristics of the absolute value of the quantized residual obtained by decoding; thus reducing codewords Use to improve the encoding and decoding efficiency of point cloud attributes and improve the encoding and decoding performance of point cloud attributes.

In yet another embodiment of the present application, see FIG. 8 , which shows a schematic flowchart of an encoding method provided by an embodiment of the present application. As shown in Figure 8, the method may include:

S801: Determine the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point.

It should be noted that the encoding method described in the embodiment of the present application specifically refers to a point cloud encoding method, and more specifically, a point cloud attribute encoding method based on symbol hiding, in order to further reduce the number of codewords used when encoding attribute information. This method can be applied to point cloud encoders (also simply called "encoders").

It should also be noted that in this embodiment of the present application, the point cloud to be processed includes at least one point. Among them, for a point in the point cloud to be processed, when encoding the point, it can be used as a point to be encoded in the point cloud to be processed, and there are multiple encoded points around the point. Here, the current point is the point to be encoded that currently needs to be encoded among the at least one point.

Further, in the embodiment of the present application, for each point in the point cloud to be processed, it corresponds to a geometric information and an attribute information; wherein, the geometric information represents the spatial relationship of the point, and the attribute information represents the attribute information of the point. .

Here, the attribute information may be a color component, or may be reflectance, refractive index, or other attributes, which are not specifically limited in the embodiments of this application. Wherein, when the attribute information is a color component, it can specifically be color information in any color space. For example, the attribute information may be color information in RGB space, color information in YUV space, color information in YCbCr space, etc., which are not specifically limited in the embodiments of the present application.

It should also be noted that in this embodiment of the present application, the decoder can process each point in the point cloud to be processed according to a preset encoding order. In some embodiments, the preset coding order may be: the original collection order of point clouds, Morton order, Hilbert order, etc., which is not specifically limited in the embodiments of this application.

It can be understood that for the current point, the attribute value (ie, the original value) of the current point can be obtained. Based on this attribute value, the symbol of the current point can be determined. Specifically, if the attribute value is greater than zero, then the sign can be stated to be positive; otherwise, if the attribute value is less than zero, then the sign can be stated to be negative. It should be noted that the attribute values here carry positive and negative signs.

Furthermore, for the current point, residual calculation needs to be performed first in order to determine the absolute value of the initial quantized residual. In some embodiments, determining the initial quantized residual absolute value of the current point may include:

Predict the attribute information of the current point and determine the attribute prediction value of the current point;

Obtain the attribute value of the current point, perform residual calculation based on the attribute value and attribute predicted value, and determine the attribute residual value of the current point;

Quantify the attribute residual value and calculate the absolute value to obtain the initial quantized residual absolute value of the current point.

It should be noted that in this embodiment of the present application, a prediction algorithm is used to perform prediction processing on the attribute information of the current point, and the attribute prediction value of the current point can be obtained, which is represented by A _j ′. Among them, j indicates that the jth point in the point cloud to be processed is the current point, and the prediction algorithm can also include an intra-frame prediction algorithm and an inter-frame prediction algorithm.

It should also be noted that the attribute value of the current point is represented by A _j , and the attribute residual value of the current point is represented by res. Then for the determination of res, for example, the calculation formula is as follows,

res＝A _j -A _j ′ (5)

In this way, after obtaining the attribute residual value res, the attribute residual value can be quantized and the absolute value can be obtained to obtain the initial quantized residual absolute value, which can be expressed by resQ.

S802: When the absolute value of the initial quantized residual meets the first preset condition, determine the absolute value of the quantized residual at the current point based on the sign and the parity characteristics of the initial quantized residual absolute value.

It should be noted that, in this embodiment of the present application, the first preset condition may be a preset judgment standard for determining whether to hide the symbol corresponding to the current point. For example, whether the initial quantized residual absolute value satisfies the first preset condition may be determined based on a comparison result between the initial quantized residual absolute value and a preset threshold. Therefore, in some embodiments, the method may further include:

If the absolute value of the initial quantized residual is greater than or equal to the preset threshold, it is determined that the absolute value of the initial quantized residual satisfies the first preset condition;

If the absolute value of the initial quantized residual is less than the preset threshold, it is determined that the absolute value of the initial quantized residual does not meet the first preset condition.

It should also be noted that, regarding whether to hide symbols, the encoding end can set a symbol to hide identification information. Therefore, in some embodiments, the method may further include:

If the absolute value of the initial quantized residual is greater than or equal to the preset threshold, then the value of the symbol hidden identification information is set to the first value;

If the absolute value of the initial quantized residual is less than the preset threshold, then the value of the symbol hidden identification information is set to the second value.

In the embodiment of this application, the first value may be 1 and the second value may be 0; or the first value may be 0 and the second value may be 1; or the first value may be true and the second value may be is false; or, the first value can be false, and the second value can be true; there is no specific limitation in the embodiment of this application.

In this embodiment of the present application, the value of the symbol hiding identification information may be used to indicate whether the current point hides the symbol of the initial quantized residual. For example, assuming that the first value is true and the second value is false, then if the absolute value of the initial quantization residual is greater than or equal to the preset threshold, it means that the symbol needs to be hidden. At this time, the value of the symbol hiding identification information can be set. is true; if the absolute value of the initial quantization residual is less than the preset threshold, it means that there is no need to hide the symbol. At this time, the value of the symbol hidden identification information can be set to false.

It can be understood that when it is determined that symbols need to be hidden, it is also necessary to determine the parity characteristics of the absolute value of the initial quantization residual. Therefore, in some embodiments, the method may further include: when the value of the symbol hidden identification information is the first value, determining the parity characteristics of the absolute value of the initial quantization residual.

In a specific embodiment, determining the parity characteristics of the absolute value of the initial quantized residual may include:

Calculate the parity characteristics of the absolute value of the initial quantized residual to obtain the parity value;

If the parity value is equal to the third value, it is determined that the absolute value of the initial quantization residual is an odd number;

If the parity value is equal to the fourth value, it is determined that the absolute value of the initial quantization residual is an even number.

It should be noted that in this embodiment of the present application, the third value is equal to 1, and the fourth value is equal to 0.

For example, it is assumed that the absolute value of the initial quantization residual is represented by resQ, and the parity value is represented by parity. At this time, calculate the parity value of the absolute value of the initial quantized residual, parity=resQ%2. Among them, if parity=1, then it can be determined that the absolute value of the initial quantized residual is an odd number; otherwise, if parity=0, then it can be determined that the absolute value of the initial quantized residual is an even number.

Further, after determining the parity characteristics of the initial quantized residual absolute value, in some embodiments, determining the quantized residual absolute value of the current point according to the sign and the parity characteristics of the initial quantized residual absolute value may include :

Determine whether the signed initial quantized residual satisfies the second preset condition according to the parity characteristics of the sign and the absolute value of the initial quantized residual;

If the signed initial quantized residual satisfies the second preset condition, then determine the absolute value of the initial quantized residual as the absolute value of the quantized residual at the current point;

If the signed initial quantized residual does not meet the second preset condition, then the absolute value of the quantized residual at the current point is determined based on the initial quantized residual absolute value and the preset constant value.

It should be noted that in the embodiment of the present application, after obtaining the signed initial quantized residual, it is determined whether the signed initial quantized residual satisfies the second preset condition, for example, whether the signed initial quantized residual is negative. Odd numbers, positive even numbers, etc. If the signed initial quantized residual meets the second preset condition, then the absolute value of the initial quantized residual is the absolute value of the quantized residual at the current point. According to the parity and even characteristics of the absolute value of the quantized residual, it can Determine the sign; and/or, if the signed initial quantized residual does not meet the second preset condition, then the absolute value of the initial quantized residual needs to be calculated to determine the absolute value of the quantized residual at the current point, and then according to the quantized The sign can be determined by the odd-even characteristic of the absolute value of the residual.

In a possible embodiment, determining whether the signed initial quantized residual satisfies the second preset condition based on the sign and the parity characteristics of the absolute value of the initial quantized residual may include:

According to the sign and the absolute value of the initial quantized residual, the signed initial quantized residual is obtained;

If the signed initial quantized residual is an even number greater than zero or an odd number less than zero, it is determined that the signed initial quantized residual satisfies the second preset condition; and/or,

If the signed initial quantized residual is an odd number greater than zero or an even number smaller than zero, it is determined that the signed initial quantized residual does not satisfy the second preset condition.

That is to say, when the hidden symbol is determined, the signed initial quantized residual is first determined; then, if the signed initial quantized residual is a positive even number (an even number greater than zero) or a negative odd number (an even number less than zero) odd number), then it can be determined that the signed initial quantized residual satisfies the second preset condition. In this case, the symbol does not need to be written into the code stream; for the decoder, if the absolute value of the quantized residual obtained by decoding is an even number, then the symbol can be determined to be a positive sign; if the absolute value of the quantized residual obtained by decoding is an odd number, Then you can determine that the sign is negative.

In another possible embodiment, determining whether the signed initial quantized residual satisfies the second preset condition based on the sign and the parity characteristics of the absolute value of the initial quantized residual may include:

If the signed initial quantized residual is an odd number greater than zero or an even number less than zero, it is determined that the signed initial quantized residual satisfies the second preset condition; and/or,

If the signed initial quantized residual is an even number greater than zero or an odd number smaller than zero, it is determined that the signed initial quantized residual does not satisfy the second preset condition.

That is to say, when the hidden symbol is determined, the signed initial quantized residual is first determined at this time; then, if the signed initial quantized residual is a positive odd number (an odd number greater than zero) or a negative even number (an odd number less than zero) even), then it can be determined that the signed initial quantized residual satisfies the second preset condition. In this case, the symbol does not need to be written into the code stream; for the decoder, if the absolute value of the quantized residual obtained by decoding is an even number, then the symbol can be determined to be a negative sign; if the absolute value of the quantized residual obtained by decoding is an odd number , then the sign can be determined to be positive.

Further, in some embodiments, the method may also include:

If the sign is positive and the absolute value of the initial quantized residual is an odd number, then the signed initial quantized residual is determined to be an odd number greater than zero;

If the sign is negative and the absolute value of the initial quantized residual is an odd number, then the signed initial quantized residual is determined to be an odd number less than zero;

If the sign is positive and the absolute value of the initial quantized residual is an even number, then the signed initial quantized residual is determined to be an even number greater than zero;

If the sign is negative and the absolute value of the initial quantized residual is an even number, then the signed initial quantized residual is determined to be an even number less than zero.

That is to say, in the embodiment of the present application, if the sign is positive and the absolute value of the initial quantized residual is an odd number, then it can be determined that the signed initial quantized residual is an odd number greater than zero, which can also be called a positive odd number. ; If the sign is negative, and the absolute value of the initial quantization residual is an odd number, then it can be determined that the signed initial quantization residual is an odd number less than zero, which can also be called a negative odd number; if the sign is positive, and the initial quantization If the absolute value of the residual is an even number, then it can be determined that the signed initial quantized residual is an even number greater than zero, which can also be called a positive even number; if the sign is negative, and the absolute value of the initial quantized residual is an even number, then it can be determined The signed initial quantized residual is an even number less than zero, which can also be called a negative even number.

Further, in the case where the signed initial quantized residual does not meet the second preset condition, in some embodiments, the current point is determined based on the absolute value of the initial quantized residual and the preset constant value. The absolute value of the quantized residual can include:

Perform an addition calculation based on the initial quantized residual absolute value and the preset constant value to obtain the first candidate quantized residual absolute value;

Perform subtraction calculation based on the initial quantized residual absolute value and the preset constant value to obtain the second candidate quantized residual absolute value;

Based on the first candidate quantized residual absolute value and the second candidate quantized residual absolute value, the quantized residual absolute value of the current point is determined.

It should be noted that in the embodiment of the present application, the value of the preset constant value may be 1, but it may also be other values, and is not specifically limited here.

It should also be noted that in the embodiment of the present application, if the signed initial quantized residual does not meet the second preset condition, then the absolute value of the initial quantized residual and the preset constant value need to be calculated, for example, plus one calculation. , minus one calculation and so on. In this way, two candidate values can be obtained: the first candidate quantization residual absolute value and the second candidate quantization residual absolute value. Among them, the former can be calculated by adding one to the absolute value of the initial quantized residual, represented by resQ ⁺ ; the latter can be calculated by subtracting one from the absolute value of the initial quantized residual, represented by resQ ^- . The absolute value of the quantized residual at the current point is then determined from resQ ⁺ and ^resQ- by performing a distortion cost calculation.

In a specific embodiment, determining the absolute value of the quantized residual at the current point based on the first candidate quantized residual absolute value and the second candidate quantized residual absolute value may include:

Determine the first candidate attribute reconstruction value according to the first candidate quantized residual absolute value, sign and attribute prediction value; and perform distortion cost calculation on the first candidate attribute reconstruction value and attribute value to obtain the first generation value;

Determine the second candidate attribute reconstruction value according to the second candidate quantized residual absolute value, sign and attribute prediction value; and perform distortion cost calculation on the second candidate attribute reconstruction value and attribute value to obtain the second generation value;

Based on the first generation value and the second generation value, the quantization residual absolute value of the current point is determined from the first candidate quantization residual absolute value and the second candidate quantization residual absolute value.

Here, you first need to use a prediction algorithm to determine the attribute prediction value of the current point; then determine the first candidate attribute reconstruction value based on the first candidate quantized residual absolute value, sign, and attribute prediction value, so as to reconstruct based on the first candidate attribute and attribute values; and determining a second candidate attribute reconstruction value based on the second candidate quantized residual absolute value, sign, and attribute prediction value, so that the second candidate attribute reconstruction value and the attribute value are calculated Second generation value.

In one possible embodiment, for the first candidate attribute the value is reconstructed (using

representation), in some embodiments, determining the first candidate attribute reconstruction value based on the first candidate quantized residual absolute value, sign and attribute prediction value may include:

Perform inverse quantization processing on the first candidate quantized residual absolute value to obtain the first candidate reconstructed residual absolute value;

According to the sign and the absolute value of the first candidate reconstruction residual, the signed first candidate reconstruction residual is obtained;

The first candidate attribute reconstruction value is obtained by adding the signed first candidate reconstruction residual and the attribute prediction value.

On the encoding side, the first candidate quantized residual absolute value needs to be inversely quantized first to obtain the first candidate reconstructed residual absolute value, represented by InvQ(resQ ⁺ ); then according to the sign and the first candidate reconstructed residual absolute value value, at this time the signed first candidate reconstruction residual can be represented by sign*InvQ(resQ ⁺ ); finally, by adding the signed first candidate reconstruction residual and the attribute prediction value, the first candidate attribute can be obtained Rebuild value. For example, the calculation formula is as follows:

For the second candidate attribute reconstruction value (using

representation), in some embodiments, determining the second candidate attribute reconstruction value based on the second candidate quantized residual absolute value, sign, and attribute prediction value may include:

Perform inverse quantization processing on the second candidate quantized residual absolute value to obtain the second candidate reconstructed residual absolute value;

According to the sign and the absolute value of the second candidate reconstruction residual, the signed second candidate reconstruction residual is obtained;

An addition operation is performed on the signed second candidate reconstruction residual and the attribute prediction value to obtain the second candidate attribute reconstruction value.

On the encoding side, it is first necessary to perform inverse quantization processing on the absolute value of the second candidate quantization residual to obtain the absolute value of the second candidate reconstruction residual, represented by InvQ (resQ ^- ); then according to the sign and the second candidate reconstruction residual Absolute value, at this time, the signed second candidate reconstruction residual can be represented by sign*InvQ(resQ ^- ); finally, by adding the signed second candidate reconstruction residual and the attribute prediction value, the second candidate can be obtained Property reconstruction value. For example, the calculation formula is as follows:

Further, if the attribute information is a color component, the color component includes at least one of the following: a first color component, a second color component, and a third color component; since there is an association between different color components, then for the color component Specifically, cross-component attribute prediction values can also be included here, represented by residualPrevComponent. Therefore, in some embodiments, the method may further include: when the attribute information is a color component, determining a cross-component attribute prediction value of the current point. Here, it should be noted that if the attribute information is reflectivity, refractive index, etc., since the reflectance does not include multiple components, and the refractive index does not include multiple components, then for attribute information such as reflectivity, refractive index, etc., then There will be no cross-component attribute predictions.

It should also be noted that if the attribute information is a color component, then when determining the attribute residual value of the current point, it is also necessary to subtract the cross-component attribute prediction value, and then perform quantization processing and obtain the absolute value to obtain the current point's The absolute value of the initial quantized residual. Correspondingly, in some embodiments, performing residual calculation based on the attribute value and attribute predicted value to determine the attribute residual value of the current point may include: performing residual calculation based on the attribute value, attribute predicted value and cross-component attribute predicted value. Difference calculation to determine the attribute residual value of the current point.

In the embodiment of this application, the attribute value of the current point is represented by A _j , the attribute prediction value of the current point is represented by A _j ′, the cross-component attribute prediction value of the current point is represented by residualPrevComponent, and the attribute residual value of the current point is still represented by res represents, then for the determination of res, for example, the calculation formula is as follows,

res＝A _j -A _j ′-residualPrevComponent (8)

In this way, after obtaining the attribute residual value res, the attribute residual value can be quantized and the absolute value can be obtained, thereby obtaining the initial quantized residual absolute value; the initial quantized residual absolute value can be calculated by adding one and subtracting one. , the first candidate quantization residual absolute value (resQ ⁺ ) and the second candidate quantization residual absolute value (resQ ^- ) can be obtained.

In another possible embodiment, for the first candidate attribute the value is reconstructed (using

The first candidate attribute reconstruction value is obtained by adding the signed first candidate reconstruction residual, the attribute prediction value, and the cross-component attribute prediction value.

On the encoding side, the first candidate quantized residual absolute value needs to be inversely quantized first to obtain the first candidate reconstructed residual absolute value, represented by InvQ(resQ ⁺ ); then according to the sign and the first candidate reconstructed residual absolute value value, at this time the signed first candidate reconstruction residual can be represented by sign*InvQ(resQ ⁺ ); finally, by adding the signed first candidate reconstruction residual, attribute prediction value and cross-component attribute prediction value, The first candidate attribute reconstruction value can be obtained. For example, the calculation formula is as follows:

For the second candidate attribute reconstruction value (using

The second candidate attribute reconstruction value is obtained by adding the signed second candidate reconstruction residual, the attribute prediction value, and the cross-component attribute prediction value.

On the encoding side, it is first necessary to perform inverse quantization processing on the absolute value of the second candidate quantization residual to obtain the absolute value of the second candidate reconstruction residual, represented by InvQ (resQ ^- ); then according to the sign and the second candidate reconstruction residual Absolute value. At this time, the signed second candidate reconstruction residual can be represented by sign*InvQ(resQ ^- ); finally, the signed second candidate reconstruction residual, attribute prediction value and cross-component attribute prediction value are added. , the second candidate attribute reconstruction value can be obtained. For example, the calculation formula is as follows:

In this way, after obtaining the first candidate attribute reconstruction value and the second candidate attribute reconstruction value, the first-generation value and the second-generation value corresponding to these two candidate values can be calculated; then based on the first-generation value and the second-generation value , the final absolute value of the quantized residual is determined from resQ ⁺ and resQ ^- .

In a possible embodiment, for determining the first generation value, calculating the distortion cost of the first candidate attribute reconstruction value and the attribute value to obtain the first generation value may include: reconstructing the value according to the first candidate attribute Calculate the absolute value of the difference with the attribute value to obtain the first absolute value of the difference, and use the first absolute value of the difference as the first generation value.

For the determination of the second generation value, calculating the distortion cost of the second candidate attribute reconstruction value and the attribute value to obtain the second generation value may include: calculating the absolute value of the difference based on the second candidate attribute reconstruction value and the attribute value. Calculate and obtain the absolute value of the second difference, and use the absolute value of the second difference as the second generation value.

It should be noted that in the embodiment of the present application, the first-generation value can be expressed as cost ⁺ , and the second-generation value can be expressed as cost ^- . Taking the distortion cost as an example, the calculation formula for the first-generation value can be as follows,

The calculation formula for the second generation value can be as follows,

Among them, abs(x) represents the absolute value of x.

In another possible embodiment, for determining the first generation value, calculating the distortion cost on the first candidate attribute reconstruction value and the attribute value to obtain the first generation value may include:

Calculate the absolute value of the difference based on the first candidate attribute reconstruction value and the attribute value to obtain the first absolute value of the difference;

The first generation value is obtained by adding the first difference absolute value and the first candidate quantized residual absolute value.

For the determination of the second generation value, the calculation of the distortion cost of the second candidate attribute reconstruction value and the attribute value to obtain the second generation value may include:

Calculate the absolute value of the difference based on the second candidate attribute reconstruction value and the attribute value to obtain the second absolute value of the difference;

The second difference absolute value and the second candidate quantized residual absolute value are added to obtain the second generation value.

It should be noted that in the embodiment of the present application, the first-generation value can be expressed as cost ⁺ , and the second-generation value can be expressed as cost ^- . Taking the rate distortion cost as an example, the calculation formula for the first generation value can also be as follows,

The calculation formula for the second generation value can also be as follows,

Among them, abs(x) represents the absolute value of x.

In yet another possible embodiment, for determining the first-generation value, calculating the distortion cost on the first candidate attribute reconstruction value and the attribute value to obtain the first-generation value may include:

Determine the first factor and the second factor;

The first generation value is obtained by performing a weighted sum operation on the absolute value of the first difference and the absolute value of the first candidate quantization residual according to the first factor and the second factor.

Determine the third and fourth factors;

A weighted sum operation is performed on the absolute value of the second difference and the absolute value of the second candidate quantization residual according to the third factor and the fourth factor to obtain the second generation value.

It should be noted that in the embodiment of the present application, the first factor can be expressed as α1, the second factor can be expressed as β1; the third factor can be expressed as α2, and the fourth factor can be expressed as β2. Among them, the first-generation value can be expressed by cost ⁺ , and the second-generation value can be expressed by cost ^- . Taking the weighted sum method as an example to calculate the distortion cost, the calculation formula for the first-generation value can also be as follows,

The calculation formula for the second generation value can also be as follows,

Among them, abs(x) represents the absolute value of x.

In yet another possible embodiment, for determining the first-generation value, the method may further include: determining the absolute value of the first candidate quantization residual as the first-generation value.

For the determination of the second generation value, the method may further include: determining the absolute value of the second candidate quantization residual as the second generation value.

It should be noted that in the embodiment of the present application, the first generation value can be directly determined based on the absolute value of the first candidate quantization residual. At this time, the distortion cost formula can also be as follows:

cost ⁺ ＝resQ ⁺ (17)

For the second generation value, the value can be determined directly based on the absolute value of the second candidate quantization residual. At this time, the distortion cost formula can also be as follows:

cost ^- =resQ ^- (18)

That is to say, in the embodiment of the present application, the calculation of the distortion cost may be to calculate the distortion cost between the candidate attribute reconstruction value and the original attribute value, or it may be to perform rate distortion on the candidate attribute reconstruction value and the original attribute value. The cost calculation can either use the weighted sum of the candidate attribute reconstruction value and the original attribute value to calculate the distortion cost, or it can use resQ ⁺ and resQ ^- to calculate the distortion cost, or even other distortion cost methods, which are not discussed here. Specific limitations. In addition, here, the candidate attribute reconstruction value may be the first candidate attribute reconstruction value or the second candidate attribute reconstruction value.

It can be understood that when it is determined that symbols need to be hidden, after determining the first-generation value and the second-generation value, the absolute value of the quantized residual at the current point can be determined based on the size of the cost value, and then the decoding end can The symbol is determined based on the parity characteristics of the absolute value of the quantized residual obtained by decoding.

In some embodiments, determining the absolute value of the quantized residual at the current point from the first candidate quantized residual absolute value and the second candidate quantized residual absolute value according to the first generation value and the second generation value may include :

If the first-generation value and the second-generation value satisfy the third preset condition and the second candidate quantized residual absolute value satisfies the fourth preset condition, then the second candidate quantized residual absolute value is determined as the quantized residual of the current point. absolute value;

If the first generation value and the second generation value do not meet the third preset condition or the second candidate quantization residual absolute value does not meet the fourth preset condition, then the first candidate quantization residual absolute value is determined as the quantization of the current point. The absolute value of the residual.

It should be noted that, in this embodiment of the present application, the third preset condition and the fourth preset condition are used to determine whether the absolute value of the quantized residual at the current point is set to the first candidate absolute value of the quantized residual or to the third candidate. The absolute value of the two candidate quantized residuals. Wherein, as to whether the first-generation value and the second-generation value meet the third preset condition, in a specific embodiment, the method may also include:

If the second-generation value is less than or equal to the first-generation value, it is determined that the first-generation value and the second-generation value meet the third preset condition;

If the second-generation value is greater than the first-generation value, it is determined that the first-generation value and the second-generation value do not meet the third preset condition.

That is to say, whether the first-generation value and the second-generation value meet the third preset condition can be determined based on the comparison between the second-generation value and the first-generation value. For example, if the second generation value is less than or equal to the first generation value, then it can be determined that the first generation value and the second generation value meet the third preset condition; otherwise, if the second generation value is greater than the first generation value, then It can be determined that the first-generation value and the second-generation value do not satisfy the third preset condition. It should be noted that for the situation where the second generation value is equal to the first generation value, it can be determined that the first generation value and the second generation value meet the third preset condition, or it can be determined that the first generation value and the second generation value If the third preset condition is not met, the embodiments of this application will not specifically limit it.

Regarding whether the second candidate quantization residual absolute value satisfies the fourth preset condition, in a specific embodiment, the method may further include:

If the absolute value of the second candidate quantized residual is greater than or equal to the preset threshold, it is determined that the absolute value of the second candidate quantized residual satisfies the fourth preset condition;

If the absolute value of the second candidate quantized residual is less than the preset threshold, it is determined that the absolute value of the second candidate quantized residual does not meet the fourth preset condition.

That is to say, whether the second candidate quantization residual absolute value satisfies the fourth preset condition can be determined based on the comparison result of the second candidate quantization residual absolute value and the preset threshold. For example, if the absolute value of the second candidate quantization residual is greater than or equal to the preset threshold, it may be determined that the second candidate quantization residual absolute value satisfies the fourth preset condition; otherwise, if the second candidate quantization residual absolute value is less than If the threshold is preset, then it can be determined that the absolute value of the second candidate quantization residual does not satisfy the fourth preset condition. It should be noted that, for the situation where the absolute value of the second candidate quantization residual is equal to the preset threshold, it may be determined that the absolute value of the second candidate quantization residual satisfies the fourth preset condition, or it may be determined that the absolute value of the second candidate quantization residual is equal to the preset threshold. If the value does not meet the fourth preset condition, the embodiment of this application does not specifically limit it.

Further, in a specific embodiment, determining the absolute value of the quantization residual at the current point from the first candidate quantization residual absolute value and the second candidate quantization residual absolute value may include:

If the second generation value is less than or equal to the first generation value, and the second candidate quantized residual absolute value is greater than or equal to the preset threshold, then the second candidate quantized residual absolute value is determined as the quantized residual absolute value of the current point;

If the second generation value is greater than the first generation value, or the second candidate quantized residual absolute value is less than the preset threshold, then the first candidate quantized residual absolute value is determined as the quantized residual absolute value of the current point.

It should be noted that in the embodiment of this application, the first-generation value is represented by cost ⁺ , the second-generation value is represented by cost ^- , the absolute value of the second candidate quantized residual is represented by resQ ^- , and the preset threshold is represented by signH. In this way, if cost ^- ≤ cost ⁺ and resQ ^- ≥ signH, then the absolute value of the quantized residual can be set to resQ ^- , that is, the absolute value of the initial quantized residual is reduced by one; otherwise, if cost ^- > cost ⁺ or resQ ^- <signH , then the absolute value of the quantized residual can be set to resQ ⁺ , that is, the absolute value of the initial quantized residual plus one. In addition, it should be noted that for the color component, the cross-component attribute prediction value also needs to be considered in order to determine the new attribute residual value and the corresponding quantized residual absolute value.

S803: Encode the absolute value of the quantization residual, and write the resulting encoded bits into the code stream.

It should be noted that when the absolute value of the initial quantized residual meets the first preset condition, it is determined that the symbol needs to be hidden; at this time, it is only necessary to encode the absolute value of the quantized residual at the current point and write the resulting coded bits. Input code stream. Subsequently, at the decoding end, after decoding to obtain the absolute value of the quantized residual, if the absolute value of the quantized residual satisfies the first preset condition, the symbol can be determined based on the parity characteristics of the absolute value of the quantized residual.

It should also be noted that for the case where the absolute value of the initial quantized residual does not meet the first preset condition, there is no need to hide the symbol at this time. Then not only the absolute value of the quantized residual needs to be written into the code stream, but also the symbol identification information needs to be written Write code stream. Therefore, in some embodiments, the method may further include:

When the absolute value of the initial quantized residual does not meet the first preset condition, the absolute value of the initial quantized residual is used as the absolute value of the quantized residual at the current point;

Determine the value of the symbol identification information, encode the value of the symbol identification information and the absolute value of the quantization residual, and write the resulting coded bits into the code stream.

Furthermore, due to the encoding of symbols, the symbol identification information may be written into the code stream according to the value (0 or 1). Therefore, in some embodiments, determining the value of symbol identification information may include:

If the symbol is a positive sign, it is determined that the value of the symbol identification information is the first value;

If the sign is a negative sign, it is determined that the value of the sign identification information is the second value.

It should be noted that in the embodiment of the present application, the first value may be 1 and the second value may be 0; or, the first value may be 0 and the second value may be 1, which are not specifically limited here.

It should also be noted that in the embodiment of the present application, for symbols (positive or negative signs), the encoding end can write the value of the symbol identification information into the code stream, so that the decoding end can parse the code stream. Determine whether the sign is positive or negative. For example, if 1 is used to represent that the symbol is positive and 0 is used to represent that the symbol is negative, then if the symbol is positive, the value of the symbol identification information can be set to 1; and/or, if the symbol is negative number, you can set the value of the symbol identification information to 0.

To put it simply, in the embodiment of the present application, in order to reduce the number of codewords required when encoding attribute information, the absolute value of the initial quantization residual at the current point can be compared with the preset threshold, and then some hidden parts to be hidden according to the parity characteristics can be introduced. Encoded symbols; so that at the decoding end, some of the symbols to be encoded do not need to be decoded from the code stream, thereby reducing the use of codewords.

The embodiment of the present application provides a coding method by determining the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point; when the absolute value of the initial quantized residual satisfies the first preset condition, According to the parity characteristics of the symbol and the initial quantized residual absolute value, the quantized residual absolute value of the current point is determined; the quantized residual absolute value is encoded, and the resulting coded bits are written into the code stream. In this way, on the encoding side, the parity characteristics based on the absolute value of the quantized residual can hide the symbols of some of the values to be encoded, that is, there is no need to encode these symbols, so as to reduce the number of code words used when encoding attribute information; thus, the number of code words can be reduced Use to improve the encoding and decoding efficiency of point cloud attributes and improve the encoding and decoding performance of point cloud attributes.

In yet another embodiment of the present application, based on the decoding method described in the previous embodiment, see FIG. 9 , which shows a detailed flowchart of an encoding method provided by the embodiment of the present application. As shown in Figure 9, taking the preset threshold as an example, the detailed process may include:

S901: Determine the attribute prediction value of the current point.

S902: Determine the attribute residual value of the current point based on the attribute value and attribute prediction value of the current point.

S903: Quantify the attribute residual value and calculate the absolute value to obtain the initial quantized residual absolute value of the current point.

S904: Compare the absolute value of the initial quantization residual with the preset threshold.

S905: If the signed initial quantization residual does not meet the second preset condition, obtain two candidate values: the first candidate quantization residual absolute value and the second candidate quantization residual absolute value; where, the first candidate quantization residual absolute value The absolute value of the residual is calculated by adding one based on the absolute value of the initial quantized residual, and the absolute value of the second candidate quantized residual is calculated by subtracting one based on the absolute value of the initial quantized residual.

S906: Perform inverse quantization processing on the absolute value of the first candidate quantized residual and the absolute value of the second candidate quantized residual respectively, and determine the signed first candidate reconstruction residual and the signed second candidate reconstruction residual; and according to the band The first candidate attribute reconstruction value is determined based on the signed first candidate reconstruction residual and the attribute prediction value, and the second candidate attribute reconstruction value is determined based on the signed second candidate reconstruction residual and the attribute prediction value.

S907: Determine the first generation value corresponding to the first candidate attribute reconstruction value and the second generation value corresponding to the second candidate attribute reconstruction value based on the distortion cost method; based on the first generation value and the second generation value, quantify the residual value from the first candidate The quantized residual absolute value of the current point is determined from the difference absolute value and the second candidate quantized residual absolute value.

S908: If the signed initial quantized residual meets the second preset condition, use the absolute value of the initial quantized residual as the absolute value of the quantized residual at the current point.

S909: Encode the absolute value of the quantization residual, and write the resulting encoded bits into the code stream.

S910: Use the initial quantized residual absolute value as the quantized residual absolute value of the current point, encode the value of the symbol identification information and the quantized residual absolute value, and write the resulting coded bits into the code stream.

It should be noted that in this embodiment of the present application, for S904, after comparing the absolute value of the initial quantized residual with the preset threshold, if the absolute value of the initial quantized residual is greater than or equal to the preset threshold, then it can be executed S905~S909, at this time, there is no need to encode the corresponding symbols, only the absolute value of the quantized residual is encoded; if the absolute value of the initial quantized residual is less than the preset threshold, then S910 can be executed. At this time, not only the absolute value of the quantized residual needs to be encoded, but also the absolute value of the quantized residual is encoded. The corresponding symbols need to be encoded.

It should also be noted that in the embodiment of the present application, when the absolute value of the initial quantized residual is greater than or equal to the preset threshold, if the signed initial quantized residual does not meet the second preset condition (for example, signed The initial quantized residual is a positive odd number or a negative even number), then S905 to S909 can be executed; if the signed initial quantized residual meets the second preset condition (for example, the signed initial quantized residual is a negative odd number or a positive even number) ), then only S909 needs to be executed. In this case, if the absolute value of the quantized residual obtained by decoding is an odd number, the sign is negative; if the absolute value of the quantized residual obtained by decoding is an even number, the sign is positive.

In addition, in the case where the absolute value of the initial quantized residual is greater than or equal to the preset threshold, if the signed initial quantized residual does not satisfy the second preset condition (for example, the signed initial quantized residual is a negative odd number or a positive even number ), then S905 to S909 can also be executed; if the signed initial quantized residual meets the second preset condition (for example, the signed initial quantized residual is a positive odd number or a negative even number), then only S909 needs to be executed at this time . In this case, if the absolute value of the quantized residual obtained by decoding is an odd number, the sign is positive; if the absolute value of the quantized residual obtained by decoding is an even number, the sign is negative.

Furthermore, in this embodiment of the present application, the encoding end may also be provided with symbolic hidden identification information. When the absolute value of the initial quantization residual is greater than or equal to the preset threshold, the symbol hiding identification information can be set to true, but the value of the symbol hiding identification information does not need to be written into the code stream. In addition, for calculating the parity value of the initial quantized residual absolute value, parity=resQ%2 can be used. Among them, if parity=1, then it can be determined to be an odd number; otherwise, if parity=0, then it can be determined to be an even number.

It should also be noted that in the embodiment of the present application, for the distortion cost method, the distortion cost may be calculated between the candidate attribute reconstruction value and the original attribute value, or the candidate attribute reconstruction value and the original attribute value may be calculated based on the ratio. Distortion cost calculation can either use the weighted sum of the candidate attribute reconstruction value and the original attribute value to calculate the distortion cost, or can use resQ ⁺ and resQ ^- to calculate the distortion cost, or even other distortion cost methods, which are not mentioned here. No specific limitation is made. In addition, here, the candidate attribute reconstruction value may be the first candidate attribute reconstruction value or the second candidate attribute reconstruction value.

It should also be noted that in the embodiment of the present application, for the color components, the encoding process shown in Figure 9 needs to be executed once for the first color component, the second color component and the third color component, and after determining the current point When obtaining attribute residual values and attribute reconstruction values, additional cross-component attribute prediction values need to be obtained. For attribute information such as reflectivity or refractive index, the encoding process shown in Figure 9 is only executed once, and there is no need to obtain additional cross-component attribute prediction values.

In a specific embodiment, for the encoding end, first, if the attribute information is a color component, the following steps are performed once for the three color components; if the attribute information is reflectance, the following steps are performed once for the reflectance. . The specific process is as follows:

b) According to the attribute value A _j and the attribute prediction value A _j ′ (and the cross-component attribute prediction value residualPrevComponent), the attribute residual res can be obtained, as follows:

res＝A _j -A _j ′(-residualPrevComponent)

b) Quantify the absolute value of the attribute residual and generate the initial quantized residual absolute value resQ;

d) Compare the absolute value of the initial quantized residual with the preset threshold (represented by signH, for example, it can be set to 4). If the absolute value of the initial quantized residual is greater than or equal to the preset threshold, perform step e), otherwise perform step e). g);

e) Specifically includes:

1) Set the symbol hidden identification information to true;

2) Calculate the parity of the absolute value of the initial quantized residual, parity=resQ%2. Among them, if the absolute value of the initial quantized residual is an odd number, then parity=1; otherwise, parity=0;

3) If the signed initial quantized residual is a positive odd number or a negative even number, then perform step 4), otherwise jump to step f);

4) Obtain two candidate values, including: the absolute value of the initial quantized residual plus one (expressed by resQ ⁺ ) and the absolute value of the initial quantized residual minus one (expressed by resQ ^- );

5) Perform inverse quantization processing on resQ ^- and resQ ⁺ respectively to obtain the reconstructed residual values InvQ (resQ ^- ) and InvQ (resQ ⁺ ); according to the reconstructed residual value and sign (sign), obtain the signed reconstructed residual value sign*InvQ(resQ ^- ) and sign*InvQ(resQ ⁺ ); then calculate the candidate attribute reconstruction values recA _j ^- and recA _j ⁺ based on the signed reconstruction residual value, as follows:

6) Calculate the distortion cost of the two candidate values through the cost equation, as follows:

7) If cost ^- ≤ cost ⁺ and resQ ^- ≥ signH, then the absolute value of the quantized residual at the current point can be set to the absolute value of the initial quantized residual minus one, otherwise the absolute value of the quantized residual at the current point can be set to the initial quantized Add one to the absolute value of the residual (it should be noted that for the color component, the cross-component attribute prediction value needs to be considered), and then perform step f);

f) Only encode the absolute value of the quantization residual |resQ|, and the encoding ends.

g) The signed quantized residual sign*resQ needs to be encoded, that is, the value of sign and the absolute value of the quantized residual |resQ| are encoded according to the relevant technology, and the encoding is completed.

Through the above embodiments, the specific implementation of the foregoing embodiments is elaborated in detail. According to the technical solutions of the foregoing embodiments, it can be seen that this technical solution provides a point cloud attribute encoding method based on symbol hiding. In order to further reduce the encoding The codewords required for attribute information can introduce symbols that hide part of the value to be encoded based on parity, so that the subsequent decoding end can determine the corresponding symbol based on the parity characteristics of the absolute value of the quantized residual obtained by decoding; thus, the number of codewords can be reduced Use to improve the encoding and decoding efficiency of point cloud attributes and improve the encoding and decoding performance of point cloud attributes.

In yet another embodiment of the present application, the embodiment of the present application provides a code stream, which is generated by bit encoding based on the information to be encoded. The information to be encoded at least includes: the absolute value of the quantized residual of the current point, or the absolute value of the quantized residual of the current point and the corresponding symbol identification information.

In yet another embodiment of the present application, based on the same inventive concept of the previous embodiment, see FIG. 10 , which shows a schematic structural diagram of an encoder provided by an embodiment of the present application. As shown in Figure 10, the encoder 100 may include: a first determining unit 1001 and an encoding unit 1002; wherein,

The first determination unit 1001 is configured to determine the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point; and when the absolute value of the initial quantized residual satisfies the first preset condition, according to the sign and The parity characteristics of the initial quantized residual absolute value determine the quantized residual absolute value of the current point;

The encoding unit 1002 is configured to encode the absolute value of the quantization residual and write the resulting encoded bits into the code stream.

In some embodiments, the first determination unit 1001 is further configured to use the initial quantized residual absolute value as the quantized residual absolute value of the current point when the initial quantized residual absolute value does not meet the first preset condition;

The encoding unit 1002 is also configured to determine the value of the symbol identification information, encode the value of the symbol identification information and the absolute value of the quantization residual, and write the resulting encoded bits into the code stream.

In some embodiments, the first determining unit 1001 is also configured to determine that the absolute value of the initial quantized residual satisfies the first preset condition if the absolute value of the initial quantized residual is greater than or equal to the preset threshold; if the absolute value of the initial quantized residual is less than the preset threshold, it is determined that the absolute value of the initial quantized residual does not meet the first preset condition.

It can be understood that in the embodiments of the present application, the "unit" may be part of a circuit, part of a processor, part of a program or software, etc., and of course may also be a module, or may be non-modular. Moreover, each component in this embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or software function modules.

If the integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment is essentially either The part that contributes to the existing technology or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions to make a computer device (can It is a personal computer, server, or network device, etc.) or processor that executes all or part of the steps of the method described in this embodiment. The aforementioned storage media include: U disk, mobile hard disk, Read Only Memory (ROM), Random Access Memory (RAM), magnetic disk or optical disk and other media that can store program code.

Therefore, embodiments of the present application provide a computer-readable storage medium for use in the encoder 100. The computer-readable storage medium stores a computer program. When the computer program is executed by the first processor, any of the foregoing embodiments can be implemented. method described in one item.

Based on the above composition of the encoder 100 and the computer-readable storage medium, see FIG. 11 , which shows a schematic diagram of the specific hardware structure of the encoder 100 provided by the embodiment of the present application. As shown in FIG. 11 , the encoder 100 may include: a first communication interface 1101 , a first memory 1102 and a first processor 1103 ; the various components are coupled together through a first bus system 1104 . It can be understood that the first bus system 1104 is used to implement connection communication between these components. In addition to the data bus, the first bus system 1104 also includes a power bus, a control bus and a status signal bus. However, for the sake of clarity of explanation, various buses are labeled as the first bus system 1104 in FIG. 11 . in,

The first communication interface 1101 is used for receiving and sending signals during the process of sending and receiving information with other external network elements;

The first memory 1102 is used to store a computer program capable of running on the first processor 1103;

The first processor 1103 is configured to execute: when running the computer program:

It can be understood that the first memory 1102 in the embodiment of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, non-volatile memory can be read-only memory (Read-Only Memory, ROM), programmable read-only memory (Programmable ROM, PROM), erasable programmable read-only memory (Erasable PROM, EPROM), electrically removable memory. Erase programmable read-only memory (Electrically EPROM, EEPROM) or flash memory. Volatile memory may be Random Access Memory (RAM), which is used as an external cache. By way of illustration, but not limitation, many forms of RAM are available, such as static random access memory (Static RAM, SRAM), dynamic random access memory (Dynamic RAM, DRAM), synchronous dynamic random access memory (Synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (Double Data Rate SDRAM, DDRSDRAM), enhanced synchronous dynamic random access memory (Enhanced SDRAM, ESDRAM), synchronous link dynamic random access memory (Synchlink DRAM, SLDRAM) and Direct Rambus RAM (DRRAM). The first memory 1102 of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

The first processor 1103 may be an integrated circuit chip with signal processing capabilities. During the implementation process, each step of the above method can be completed by instructions in the form of hardware integrated logic circuits or software in the first processor 1103 . The above-mentioned first processor 1103 can be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), or an off-the-shelf programmable gate array (Field Programmable Gate Array, FPGA). or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. Each method, step and logical block diagram disclosed in the embodiment of this application can be implemented or executed. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly implemented by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software module can be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other mature storage media in this field. The storage medium is located in the first memory 1102. The first processor 1103 reads the information in the first memory 1102 and completes the steps of the above method in combination with its hardware.

It will be understood that the embodiments described in this application can be implemented using hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more Application Specific Integrated Circuits (ASIC), Digital Signal Processing (DSP), Digital Signal Processing Device (DSP Device, DSPD), programmable Logic device (Programmable Logic Device, PLD), Field-Programmable Gate Array (FPGA), general-purpose processor, controller, microcontroller, microprocessor, and other devices used to perform the functions described in this application electronic unit or combination thereof. For software implementation, the technology described in this application can be implemented through modules (such as procedures, functions, etc.) that perform the functions described in this application. Software code may be stored in memory and executed by a processor. The memory can be implemented in the processor or external to the processor.

Optionally, as another embodiment, the first processor 1103 is further configured to perform the method described in any one of the preceding embodiments when running the computer program.

This embodiment provides an encoder in which the symbols of some values to be encoded can be hidden based on the parity characteristics of the absolute value of the quantized residual, that is, there is no need to encode these symbols, so as to reduce the time required for encoding attribute information. The code words used; thereby reducing the use of code words, improving the coding efficiency of point cloud attributes, and improving the coding performance of point cloud attributes.

Based on the same inventive concept of the previous embodiment, see FIG. 12 , which shows a schematic structural diagram of a decoder 120 provided by an embodiment of the present application. As shown in Figure 12, the decoder 120 may include: a decoding unit 1201 and a second determination unit 1202; wherein,

The decoding unit 1201 is configured to parse the code stream and determine the absolute value of the quantization residual at the current point;

The second determination unit 1202 is configured to determine the sign of the quantized residual at the current point according to the parity characteristics of the absolute value of the quantized residual when the absolute value of the quantized residual satisfies the first preset condition; and based on the absolute value of the quantized residual Value and sign, determine the attribute reconstruction value of the current point.

In some embodiments, the decoding unit 1201 is further configured to parse the code stream and determine the sign of the quantized residual at the current point when the absolute value of the quantized residual does not meet the first preset condition.

In some embodiments, the decoding unit 1201 is also configured to parse the code stream and obtain the value of the symbol identification information;

The second determining unit 1202 is further configured to determine that the symbol is a positive sign if the value of the symbol identification information is a first value; and to determine that the symbol is a positive sign if the value of the symbol identification information is a second value. The sign is negative.

It can be understood that in this embodiment, the "unit" may be part of a circuit, part of a processor, part of a program or software, etc., and of course may also be a module, or may be non-modular. Moreover, each component in this embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or software function modules.

If the integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, this embodiment provides a computer-readable storage medium for use in the decoder 120. The computer-readable storage medium stores a computer program. When the computer program is executed by the second processor, the foregoing embodiments are implemented. any one of the methods.

Based on the above composition of the decoder 120 and the computer-readable storage medium, see FIG. 13 , which shows a schematic diagram of the specific hardware structure of the decoder 120 provided by the embodiment of the present application. As shown in Figure 13, the decoder 120 may include: a second communication interface 1301, a second memory 1302, and a second processor 1303; the various components are coupled together through a second bus system 1304. It can be understood that the second bus system 1304 is used to implement connection communication between these components. In addition to the data bus, the second bus system 1304 also includes a power bus, a control bus and a status signal bus. However, for the sake of clarity of explanation, various buses are labeled as second bus system 1304 in FIG. 13 . in,

The second communication interface 1301 is used for receiving and sending signals during the process of sending and receiving information with other external network elements;

The second memory 1302 is used to store a computer program capable of running on the second processor 1303;

The second processor 1303 is configured to execute: when running the computer program:

Optionally, as another embodiment, the second processor 1303 is further configured to perform the method described in any one of the preceding embodiments when running the computer program.

It can be understood that the hardware functions of the second memory 1302 and the first memory 1102 are similar, and the hardware functions of the second processor 1303 and the first processor 1103 are similar; details will not be described here.

This embodiment provides a decoder, in which the parity and even characteristics of the absolute value of the quantized residual obtained by decoding are used to determine the corresponding symbol; thereby reducing the use of codewords and improving the encoding and decoding efficiency of point cloud attributes. , while improving the encoding and decoding performance of point cloud attributes.

In yet another embodiment of the present application, see FIG. 14 , which shows a schematic structural diagram of a coding and decoding system provided by an embodiment of the present application. As shown in Figure 14, the encoding and decoding system 140 may include an encoder 1401 and a decoder 1402. The encoder 1401 may be the encoder described in any of the preceding embodiments, and the decoder 1402 may be the decoder described in any of the preceding embodiments.

In the embodiment of the present application, in the encoding and decoding system 140, in the encoder 1401, based on the parity characteristics of the absolute value of the quantized residual, some symbols of the values to be encoded can be hidden, that is, there is no need to encode these partial symbols to reduce the properties. The code words used when encoding information; in the decoder 1402, the corresponding symbols can be directly determined based on the parity characteristics of the absolute value of the quantized residual obtained by decoding; thus, the use of code words can be reduced and the encoding and decoding of point cloud attributes can be improved. efficiency, while improving the encoding and decoding performance of point cloud attributes.

It should be noted that in this application, the terms "comprising", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device that includes a series of elements not only includes those elements , but also includes other elements not expressly listed or inherent in such process, method, article or apparatus. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, method, article or apparatus that includes that element.

The above serial numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments.

The methods disclosed in several method embodiments provided in this application can be combined arbitrarily to obtain new method embodiments without conflict.

The features disclosed in several product embodiments provided in this application can be combined arbitrarily without conflict to obtain new product embodiments.

The features disclosed in several method or device embodiments provided in this application can be combined arbitrarily without conflict to obtain new method embodiments or device embodiments.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application. should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Industrial applicability

In the embodiment of the present application, at the encoding end, the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point are determined; when the absolute value of the initial quantized residual satisfies the first preset condition, according to the sign and the parity characteristics of the initial quantized residual absolute value, determine the quantized residual absolute value of the current point; encode the quantized residual absolute value, and write the resulting coded bits into the code stream. At the decoding end, the code stream is parsed to determine the absolute value of the quantized residual at the current point; when the absolute value of the quantized residual meets the first preset condition, the quantized residual at the current point is determined based on the parity characteristics of the absolute value of the quantized residual. The sign of the difference; determine the attribute reconstruction value of the current point based on the absolute value and sign of the quantized residual. In this way, on the encoding side, the parity characteristics based on the absolute value of the quantized residual can hide some symbols of the values to be encoded, that is, there is no need to encode these symbols, so as to reduce the codewords used when encoding attribute information; while on the decoding side, The corresponding symbol can be directly determined based on the parity and even characteristics of the absolute value of the quantized residual obtained by decoding; thus, the use of codewords can be reduced, the encoding and decoding efficiency of point cloud attributes can be improved, and the encoding and decoding performance of point cloud attributes can be improved.

Claims

A decoding method, the method includes:

Analyze the code stream and determine the absolute value of the quantized residual at the current point;

When the absolute value of the quantized residual satisfies the first preset condition, determine the sign of the quantized residual at the current point according to the parity characteristics of the absolute value of the quantized residual;

According to the absolute value of the quantized residual and the sign, the attribute reconstruction value of the current point is determined.
The method according to claim 1, wherein determining the sign of the quantized residual of the current point according to the parity characteristics of the absolute value of the quantized residual includes:

If the absolute value of the quantized residual is an odd number, the sign is determined to be negative;

If the absolute value of the quantized residual is an even number, then the sign is determined to be positive;

or,

If the absolute value of the quantized residual is an odd number, the sign is determined to be positive;

If the absolute value of the quantized residual is an even number, the sign is determined to be negative.
The method of claim 1, further comprising:

When the absolute value of the quantized residual does not satisfy the first preset condition, the code stream is parsed to determine the sign of the quantized residual at the current point.
The method according to claim 3, wherein the parsing the code stream and determining the sign of the quantized residual of the current point includes:

Parse the code stream and obtain the value of the symbol identification information;

If the value of the symbol identification information is the first value, it is determined that the symbol is a positive sign;

If the value of the symbol identification information is the second value, it is determined that the symbol is a negative sign.
The method of claim 3, further comprising:

If the absolute value of the quantized residual is greater than or equal to the preset threshold, it is determined that the absolute value of the quantized residual satisfies the first preset condition;

If the absolute value of the quantized residual is less than the preset threshold, it is determined that the absolute value of the quantized residual does not satisfy the first preset condition.
The method according to any one of claims 1 to 5, wherein the method further includes:

Predict the attribute information of the current point and determine the attribute prediction value of the current point;

Determining the attribute reconstruction value of the current point based on the absolute value of the quantized residual and the sign includes:

Perform inverse quantization processing on the absolute value of the quantized residual to obtain a decoded residual value;

determining a signed decoding residual value based on the decoding residual value and the symbol;

According to the attribute prediction value and the signed decoding residual value, the attribute reconstruction value of the current point is determined.
The method according to claim 6, wherein determining the attribute reconstruction value of the current point according to the attribute prediction value and the signed decoding residual value includes:

An addition operation is performed on the attribute prediction value and the signed decoding residual value to obtain the attribute reconstruction value of the current point.
The method of claim 6, further comprising:

When the attribute information is a color component, determine the cross-component attribute prediction value of the current point;

Determining the attribute reconstruction value of the current point based on the attribute prediction value and the signed decoding residual value includes:

The attribute prediction value, the signed decoding residual value and the cross-component attribute prediction value are added to obtain the attribute reconstruction value of the current point.
The method of claim 8, wherein the color component includes at least one of the following: a first color component, a second color component, and a third color component; wherein,

If the color component conforms to the RGB color space, it is determined that the first color component, the second color component and the third color component are respectively one of: R component, G component, and B component;

If the color component conforms to the YUV color space, it is determined that the first color component, the second color component and the third color component are respectively one of them: Y component, U component, or V component.
An encoding method, the method includes:

Determine the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point;

In the case where the initial quantized residual absolute value satisfies the first preset condition, determine the quantized residual absolute value of the current point according to the sign and the parity characteristics of the initial quantized residual absolute value;

The absolute value of the quantization residual is encoded, and the resulting encoded bits are written into the code stream.
The method of claim 10, wherein the method further includes:

In the case where the initial quantized residual absolute value does not meet the first preset condition, the initial quantized residual absolute value is used as the quantized residual absolute value of the current point;

Determine the value of the symbol identification information, encode the value of the symbol identification information and the absolute value of the quantization residual, and write the resulting coded bits into the code stream.
The method according to claim 11, wherein determining the value of symbol identification information includes:

If the symbol is a positive sign, determine that the value of the symbol identification information is the first value;

If the symbol is a negative sign, it is determined that the value of the symbol identification information is the second value.
The method of claim 11, wherein the method further includes:

If the absolute value of the initial quantized residual is greater than or equal to the preset threshold, it is determined that the absolute value of the initial quantized residual satisfies the first preset condition;

If the absolute value of the initial quantized residual is less than the preset threshold, it is determined that the absolute value of the initial quantized residual does not satisfy the first preset condition.
The method of claim 13, wherein the method further includes:

If the absolute value of the initial quantized residual is greater than or equal to the preset threshold, then set the value of the symbol hidden identification information to the first value;

If the absolute value of the initial quantized residual is less than the preset threshold, then the value of the symbol hiding identification information is set to the second value.
The method of claim 14, wherein the method further includes:

When the value of the symbol hidden identification information is a first value, determine the parity characteristics of the absolute value of the initial quantized residual;

Determining the absolute value of the quantized residual at the current point based on the parity characteristics of the symbol and the initial quantized residual absolute value includes:

Determine whether the signed initial quantized residual satisfies a second preset condition according to the parity characteristics of the sign and the absolute value of the initial quantized residual;

If the signed initial quantized residual satisfies the second preset condition, then determine the absolute value of the initial quantized residual as the absolute value of the quantized residual of the current point;

If the signed initial quantized residual does not satisfy the second preset condition, then the absolute value of the quantized residual at the current point is determined based on the initial quantized residual absolute value and a preset constant value.
The method of claim 15, wherein determining the parity characteristics of the absolute value of the initial quantized residual includes:

Calculate parity characteristics on the absolute value of the initial quantized residual to obtain parity values;

If the parity value is equal to the third value, it is determined that the absolute value of the initial quantized residual is an odd number;

If the parity value is equal to the fourth value, it is determined that the absolute value of the initial quantized residual is an even number.
The method of claim 16, wherein determining whether the signed initial quantized residual satisfies a second preset condition based on the sign and the parity characteristics of the initial quantized residual absolute value includes:

According to the sign and the absolute value of the initial quantized residual, the signed initial quantized residual is obtained;

If the signed initial quantized residual is an even number greater than zero or an odd number less than zero, then it is determined that the signed initial quantized residual satisfies the second preset condition;

If the signed initial quantized residual is an odd number greater than zero or an even number smaller than zero, it is determined that the signed initial quantized residual does not satisfy the second preset condition;

or,

If the signed initial quantized residual is an odd number greater than zero or an even number smaller than zero, then it is determined that the signed initial quantized residual satisfies the second preset condition;

If the signed initial quantized residual is an even number greater than zero or an odd number smaller than zero, it is determined that the signed initial quantized residual does not satisfy the second preset condition.
The method of claim 17, further comprising:

If the sign is positive and the absolute value of the initial quantized residual is an odd number, then it is determined that the signed initial quantized residual is an odd number greater than zero;

If the sign is a negative sign and the absolute value of the initial quantized residual is an odd number, then it is determined that the signed initial quantized residual is an odd number less than zero;

If the sign is positive and the absolute value of the initial quantized residual is an even number, then it is determined that the signed initial quantized residual is an even number greater than zero;

If the sign is a negative sign and the absolute value of the initial quantized residual is an even number, it is determined that the signed initial quantized residual is an even number less than zero.
The method according to claim 15, wherein determining the initial quantized residual absolute value of the current point includes:

Predict the attribute information of the current point and determine the attribute prediction value of the current point;

Obtain the attribute value of the current point, perform residual calculation based on the attribute value and the attribute prediction value, and determine the attribute residual value of the current point;

The attribute residual value is quantized and the absolute value is calculated to obtain the initial quantized residual absolute value of the current point.
The method according to claim 19, wherein determining the absolute value of the quantized residual of the current point based on the initial absolute value of the quantized residual and a preset constant value includes:

Perform an addition calculation based on the initial quantized residual absolute value and the preset constant value to obtain a first candidate quantized residual absolute value;

Perform subtraction calculation according to the initial quantized residual absolute value and the preset constant value to obtain a second candidate quantized residual absolute value;

A quantized residual absolute value of the current point is determined based on the first candidate quantized residual absolute value and the second candidate quantized residual absolute value.
The method of claim 20, wherein determining the absolute value of the quantized residual of the current point based on the first candidate quantized residual absolute value and the second candidate quantized residual absolute value includes:

Determine a first candidate attribute reconstruction value according to the first candidate quantized residual absolute value, the symbol and the attribute prediction value; and perform a distortion cost calculation on the first candidate attribute reconstruction value and the attribute value, Get the first generation value;

Determine a second candidate attribute reconstruction value according to the second candidate quantized residual absolute value, the symbol and the attribute prediction value; and perform a distortion cost calculation on the second candidate attribute reconstruction value and the attribute value, Get second generation value;

The quantized residual absolute value of the current point is determined from the first candidate quantized residual absolute value and the second candidate quantized residual absolute value based on the first generation value and the second generation value.
The method of claim 21 , wherein the first candidate quantized residual absolute value and the second candidate quantized residual absolute value are obtained based on the first generation value and the second generation value. Determine the absolute value of the quantized residual of the current point, including:

If the first generation value and the second generation value satisfy the third preset condition and the second candidate quantization residual absolute value satisfies the fourth preset condition, then the second candidate quantization residual absolute value is Determine the absolute value of the quantized residual as the current point;

If the first-generation value and the second-generation value do not meet the third preset condition or the second candidate quantized residual absolute value does not meet the fourth preset condition, then the first The candidate quantized residual absolute value is determined as the quantized residual absolute value of the current point.
The method of claim 22, wherein the method further includes:

If the second generation value is less than or equal to the first generation value, it is determined that the first generation value and the second generation value meet the third preset condition;

If the second generation value is greater than the first generation value, it is determined that the first generation value and the second generation value do not meet the third preset condition.
The method of claim 22, wherein the method further includes:

If the absolute value of the second candidate quantized residual is greater than or equal to the preset threshold, it is determined that the absolute value of the second candidate quantized residual satisfies the fourth preset condition;

If the absolute value of the second candidate quantized residual is less than the preset threshold, it is determined that the absolute value of the second candidate quantized residual does not satisfy the fourth preset condition.
The method according to claim 21, wherein said performing distortion cost calculation on said first candidate attribute reconstruction value and said attribute value to obtain the first generation value includes:

Calculate the absolute value of the difference according to the first candidate attribute reconstruction value and the attribute value to obtain the first absolute value of the difference, and use the first absolute value of the difference as the first generation value;

Calculating the distortion cost on the second candidate attribute reconstruction value and the attribute value to obtain the second generation value includes:

The absolute value of the difference is calculated based on the second candidate attribute reconstruction value and the attribute value to obtain a second absolute value of the difference, and the second absolute value of the difference is used as the second generation value.
The method according to claim 21, wherein said performing distortion cost calculation on said first candidate attribute reconstruction value and said attribute value to obtain the first generation value includes:

Calculate the absolute value of the difference according to the first candidate attribute reconstruction value and the attribute value to obtain the first absolute value of the difference;

Add the first difference absolute value and the first candidate quantized residual absolute value to obtain the first generation value;

Calculating the distortion cost on the second candidate attribute reconstruction value and the attribute value to obtain the second generation value includes:

Calculate the absolute value of the difference according to the second candidate attribute reconstruction value and the attribute value to obtain a second absolute value of the difference;

The second generation value is obtained by adding the second difference absolute value and the second candidate quantization residual absolute value.
The method of claim 26, wherein the method further includes:

Determine the first factor and the second factor;

Perform a weighted sum operation on the first difference absolute value and the first candidate quantization residual absolute value according to the first factor and the second factor to obtain the first generation value;

The method also includes:

Determine the third and fourth factors;

The second generation value is obtained by performing a weighted sum operation on the second difference absolute value and the second candidate quantization residual absolute value according to the third factor and the fourth factor.
The method of claim 21, wherein the method further includes:

determining the first candidate quantized residual absolute value as the first generation value;

The second candidate quantized residual absolute value is determined as the second generation value.
The method of claim 21, wherein determining the first candidate attribute reconstruction value based on the first candidate quantized residual absolute value, the sign, and the attribute prediction value includes:

Perform inverse quantization processing on the first candidate quantized residual absolute value to obtain the first candidate reconstructed residual absolute value;

Obtain a signed first candidate reconstruction residual according to the symbol and the absolute value of the first candidate reconstruction residual;

Perform an addition operation on the signed first candidate reconstruction residual and the attribute prediction value to obtain the first candidate attribute reconstruction value;

Determining a second candidate attribute reconstruction value based on the second candidate quantized residual absolute value, the symbol, and the attribute prediction value includes:

Perform inverse quantization processing on the second candidate quantized residual absolute value to obtain a second candidate reconstructed residual absolute value;

Obtain a signed second candidate reconstruction residual according to the symbol and the absolute value of the second candidate reconstruction residual;

An addition operation is performed on the signed second candidate reconstruction residual and the attribute prediction value to obtain the second candidate attribute reconstruction value.
The method of claim 21, wherein the method further includes:

When the attribute information is a color component, determine the cross-component attribute prediction value of the current point;

The step of performing residual calculation based on the attribute value and the attribute predicted value and determining the attribute residual value of the current point includes: based on the attribute value, the attribute predicted value and the cross-component attribute predicted value. Perform residual calculation to determine the attribute residual value of the current point.
The method of claim 30, wherein determining the first candidate attribute reconstruction value based on the first candidate quantized residual absolute value, the sign and the attribute prediction value includes:

Perform inverse quantization processing on the first candidate quantized residual absolute value to obtain the first candidate reconstructed residual absolute value;

Obtain a signed first candidate reconstruction residual according to the symbol and the absolute value of the first candidate reconstruction residual;

Perform an addition operation on the signed first candidate reconstruction residual, the attribute prediction value and the cross-component attribute prediction value to obtain the first candidate attribute reconstruction value;

Determining a second candidate attribute reconstruction value based on the second candidate quantized residual absolute value, the symbol, and the attribute prediction value includes:

Perform inverse quantization processing on the second candidate quantized residual absolute value to obtain a second candidate reconstructed residual absolute value;

Obtain a signed second candidate reconstruction residual according to the symbol and the absolute value of the second candidate reconstruction residual;

An addition operation is performed on the signed second candidate reconstruction residual, the attribute prediction value and the cross-component attribute prediction value to obtain the second candidate attribute reconstruction value.
The method of claim 30, wherein the color component includes at least one of the following: a first color component, a second color component, and a third color component; wherein,

If the color component conforms to the RGB color space, it is determined that the first color component, the second color component and the third color component are respectively one of: R component, G component, and B component;

If the color component conforms to the YUV color space, it is determined that the first color component, the second color component and the third color component are respectively one of them: Y component, U component, V component.
A code stream, the code stream is generated by bit encoding according to the information to be encoded; wherein the information to be encoded at least includes: the absolute value of the quantized residual of the current point, or the absolute value of the quantized residual of the current point. value and corresponding symbol identification information.
An encoder, the encoder includes a first determination unit and a coding unit; wherein,

The first determination unit is configured to determine the initial quantized residual absolute value of the current point and the sign of the initial quantized residual of the current point; and when the initial quantized residual absolute value satisfies a first preset condition Next, determine the quantized residual absolute value of the current point according to the parity characteristics of the symbol and the initial quantized residual absolute value;

The encoding unit is configured to encode the absolute value of the quantization residual and write the resulting encoded bits into a code stream.
An encoder, the encoder includes a first memory and a first processor; wherein,

The first memory is used to store a computer program capable of running on the first processor;

The first processor is configured to execute the method according to any one of claims 10 to 32 when running the computer program.
A decoder, the decoder includes a decoding unit and a second determination unit; wherein,

The decoding unit is configured to parse the code stream and determine the absolute value of the quantized residual at the current point;

The second determination unit is configured to determine the sign of the quantized residual at the current point according to the parity characteristics of the absolute value of the quantized residual when the absolute value of the quantized residual satisfies the first preset condition. ; And determine the attribute reconstruction value of the current point according to the absolute value of the quantized residual and the sign.
A decoder, the decoder includes a second memory and a second processor; wherein,

The second memory is used to store a computer program capable of running on the second processor;

The second processor is configured to execute the method according to any one of claims 1 to 9 when running the computer program.
A computer-readable storage medium, wherein the computer-readable storage medium stores a computer program. When the computer program is executed, the method of any one of claims 1 to 9 is implemented, or the method of claims 10 to 9 is implemented. The method described in any one of 32.