WO2022188164A1

WO2022188164A1 - Point cloud attribute decoding method and point cloud attribute encoding method

Info

Publication number: WO2022188164A1
Application number: PCT/CN2021/080539
Authority: WO
Inventors: 李璞; 郑萧桢
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2021-03-12
Filing date: 2021-03-12
Publication date: 2022-09-15
Also published as: CN116601672A

Abstract

Disclosed in embodiments of the present application is a point cloud attribute decoding method, comprising: decoding a color identifier of a point cloud attribute from a code stream; when the color identifier indicates that the point cloud attribute includes color data, decoding, from the code stream, an offset of a quantization parameter of a chrominance channel; calculating the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel; performing, by using the quantization parameter of the chrominance channel, inverse quantization on a chrominance residual corresponding to the chrominance channel; and when the color identifier indicates that the point cloud attribute does not include color data, determining that there is no offset of the quantization parameter of the chrominance channel in the code stream. According to the method disclosed in the embodiments of the present application, the number of bits used for point cloud data transmission is reduced.

Description

Point cloud attribute decoding method and point cloud attribute encoding method

technical field

The present application relates to the technical field of point cloud processing, and in particular, to a point cloud attribute decoding method and a point cloud attribute encoding method.

Background technique

A point cloud is a representation of a three-dimensional object or scene, which is composed of a set of discrete points that are randomly distributed in space and express the spatial structure and surface properties of a three-dimensional object or scene. To accurately reflect information in space, the number of discrete points required is enormous. In order to reduce the bandwidth occupied by point cloud data storage and transmission, the point cloud data needs to be encoded and compressed.

SUMMARY OF THE INVENTION

In view of this, the embodiments of the present application provide a point cloud attribute decoding method and a point cloud attribute encoding method, one of which is to reduce the number of bits used for point cloud data transmission.

A first aspect of the embodiments of the present application provides a point cloud attribute decoding method, including:

Decode the color identification of point cloud attributes from the code stream;

When the color identifier indicates that the point cloud attribute contains color data, decoding the offset of the quantization parameter of the chrominance channel from the code stream;

Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

Perform inverse quantization on the chrominance residual corresponding to the chrominance channel by using the quantization parameter of the chrominance channel;

When the color identifier indicates that the point cloud attribute does not contain color data, it is determined that there is no offset of the quantization parameter of the chrominance channel in the code stream.

A second aspect of the embodiments of the present application provides a point cloud attribute encoding method, including:

Get the point cloud to be encoded;

generating a color identifier for indicating whether the point cloud attribute of the point cloud to be encoded contains color data, and encoding the color identifier into a code stream;

When the color identifier indicates that the point cloud attribute of the to-be-coded point cloud contains color data, the offset of the quantization parameter of the chrominance channel is encoded to the code stream;

Using the quantization parameter of the chrominance channel to quantize the chrominance residual corresponding to the chrominance channel;

When the color identification indicates that the point cloud attribute of the point cloud to be encoded does not contain color data, the offset of the quantization parameter of the chrominance channel is not encoded.

A third aspect of the embodiments of the present application provides a point cloud attribute decoding method, including:

Decode the offsets of the quantization parameters corresponding to each of the multiple chrominance channels from the code stream;

For each chrominance channel in the plurality of chrominance channels, calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

For each chrominance channel, use the quantization parameter of the chrominance channel to perform inverse quantization on the chrominance residual corresponding to the chrominance channel.

A fourth aspect of the embodiments of the present application provides a point cloud attribute encoding method, including:

encoding the offsets of the quantization parameters corresponding to the multiple chrominance channels into the code stream;

For each chrominance channel, the chrominance residual corresponding to the chrominance channel is quantized by using the quantization parameter of the chrominance channel.

A fifth aspect of the embodiments of the present application provides a point cloud attribute decoding method, including:

Decode the offset of the quantization parameter of the chrominance channel from the code stream, the offset of the quantization parameter of the chrominance channel is a signed number;

The chrominance residual corresponding to the chrominance channel is inversely quantized by using the quantization parameter of the chrominance channel.

A sixth aspect of the embodiments of the present application provides a point cloud attribute encoding method, including:

encoding the offset of the quantization parameter of the chrominance channel into the code stream, the offset of the quantization parameter of the chrominance channel being a signed number;

The chrominance residual corresponding to the chrominance channel is quantized by using the quantization parameter of the chrominance channel.

A seventh aspect of an embodiment of the present application provides a point cloud attribute decoding device, comprising: a processor and a memory storing a computer program, where the processor implements the following steps when executing the computer program:

Decode the color identification of point cloud attributes from the code stream;

An eighth aspect of an embodiment of the present application provides a point cloud attribute encoding device, including: a processor and a memory storing a computer program, where the processor implements the following steps when executing the computer program:

Get the point cloud to be encoded;

A ninth aspect of an embodiment of the present application provides a point cloud attribute decoding device, comprising: a processor and a memory storing a computer program, where the processor implements the following steps when executing the computer program:

A tenth aspect of the embodiments of the present application provides a point cloud attribute encoding device, including: a processor and a memory storing a computer program, where the processor implements the following steps when executing the computer program:

An eleventh aspect of the embodiments of the present application provides a point cloud attribute decoding device, including: a processor and a memory storing a computer program, where the processor implements the following steps when executing the computer program:

A twelfth aspect of an embodiment of the present application provides a point cloud attribute encoding device, comprising: a processor and a memory storing a computer program, where the processor implements the following steps when executing the computer program:

A thirteenth aspect of an embodiment of the present application provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, implements the point cloud attribute decoding method of the first aspect.

A fourteenth aspect of an embodiment of the present application provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, implements the point cloud attribute encoding method of the second aspect.

A fifteenth aspect of the embodiments of the present application provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and the computer program implements the point cloud attribute decoding method of the third aspect when the computer program is executed by a processor.

A sixteenth aspect of an embodiment of the present application provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, implements the point cloud attribute encoding method of the fourth aspect.

A seventeenth aspect of an embodiment of the present application provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, implements the point cloud attribute decoding method of the fifth aspect.

An eighteenth aspect of an embodiment of the present application provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, implements the point cloud attribute encoding method of the sixth aspect.

The point cloud attribute encoding and decoding method provided by the embodiment of the present application can encode the offset of the quantization parameter of the chrominance channel only when the point cloud attribute of the point cloud to be encoded contains color data, and the point cloud attribute of the point cloud to be encoded The offsets of the quantization parameters of the chroma channels may not be encoded when color data is not included, thereby saving bits.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the drawings that are used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative labor.

FIG. 1 is a first flowchart of a point cloud attribute decoding method provided by an embodiment of the present application.

FIG. 2 is a first flowchart of a point cloud attribute encoding method provided by an embodiment of the present application.

FIG. 3 is a second flowchart of a point cloud attribute decoding method provided by an embodiment of the present application.

FIG. 4 is a second flowchart of a point cloud attribute encoding method provided by an embodiment of the present application.

FIG. 5 is a third flowchart of a point cloud attribute decoding method provided by an embodiment of the present application.

FIG. 6 is a third flowchart of a point cloud attribute encoding method provided by an embodiment of the present application.

FIG. 7 is a schematic structural diagram of a point cloud attribute decoding apparatus provided by an embodiment of the present application.

FIG. 8 is a schematic structural diagram of an apparatus for encoding a point cloud attribute provided by an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

Point cloud data can include geometric data and attribute data. For a point cloud point, the geometric data of the point cloud point may be the geometric coordinates of the point cloud point in three-dimensional space, and the attribute data of the point cloud point may include one or more of the following: color, reflectance, Timestamps, transparency, normals corresponding to the slices where they are located, etc.

The geometric data and attribute data of the point cloud are usually encoded and decoded separately. In one embodiment, since the point cloud attribute encoding and decoding needs to use the point cloud geometric data, the point cloud geometry encoding and decoding may be performed first, and then the point cloud attribute encoding and decoding is performed after the point cloud geometry encoding and decoding is completed.

After completing the point cloud geometry encoding and decoding, in one embodiment, the point cloud may be reordered first. There are many ways to sort point clouds. In some examples, each point cloud point can be sorted according to the size of Morton code. In some examples, each point cloud point can also be sorted according to the size of Hilbert code. sort. Here, each point cloud point can calculate the corresponding Morton code and Hilbert code according to its geometric coordinates, so that according to the size of Morton code or Hilbert code, it can be divided into large to small or small to large. Sequential Sorts individual point cloud points. In one embodiment, if each point cloud point is encoded and decoded in sequence according to Morton order or Hilbert order when performing geometric encoding and decoding on the point cloud, then each point cloud point after reconstructing the geometric data has Arranged in Morton order or Hilbert order, there is no need to reorder the point cloud first when encoding and decoding the point cloud attributes.

For the encoding and decoding of point cloud attributes, in one embodiment, it can be performed by means of attribute prediction. The so-called attribute prediction means that when the decoding end reconstructs the attribute value of the current point cloud point, the attribute value of the point cloud point that has been reconstructed (encoded and decoded) can be used to calculate the attribute prediction value of the current point cloud point. It is necessary to encode the difference between the actual value of the attribute of the current point cloud point and the predicted value of the attribute of the current point cloud point (that is, the attribute residual) into the code stream, and the decoding end can decode the attribute residual from the code stream. The attribute value of the current point cloud point is reconstructed by using the attribute residual and the attribute prediction value of the current point cloud point. The encoding and decoding of point cloud attributes is carried out by means of attribute prediction, and the attribute residuals can be transmitted between the encoding end and the decoding end, which greatly reduces the amount of data to be transmitted and has the effect of data compression. Here, the attribute value of the point cloud point may be the attribute value of any of the aforementioned color, reflectivity, transparency, etc.

For ease of understanding, an example can be given. In this example, the point clouds can be arranged in Morton order, and the encoding end can traverse the point cloud points in the point cloud in Morton order. Specifically, for the first point cloud point, since there is no point cloud point that has been encoded and decoded before it, the predicted value of its attribute can be set to 0, and the true value of the attribute of the current point cloud point can be recorded as A ₀ , then The attribute residual R ₀ corresponding to the first point cloud point is: R ₀ =A ₀ . For other point cloud points other than the first point cloud point, the current point cloud point can be calculated according to the attribute reconstruction value of several point cloud points before the Morton sequence (these point cloud points have been encoded and decoded) The attribute prediction value of the point cloud point is A' _i , and the real value of the attribute of the current point cloud point can be recorded as A _i , then the attribute residual R _i is: R _i =A _i -A' _i .

In an implementation manner, the encoding end may quantize the attribute residual before encoding the calculated attribute residual into the code stream. Quantization can realize the compression of attribute residuals, thereby further reducing the amount of data transmitted. Specifically, quantization can map attribute residuals with similar numerical values to the same numerical value, that is, the attribute residuals with similar numerical values are no longer distinguished, but the numerical values of these attribute residuals are considered to be the same. For example, such as the sequence {6,2,5,4,3,1}, in a quantization method, the values in the interval [1,3] can be mapped to 0, and the values in the interval [4, 6] is mapped to 1, then the quantized sequence can be changed to {1,0,1,1,0,0}, that is, ignoring the difference between 1, 2, 3 and between 4, 5, and 6 difference.

When quantizing the attribute residual, in one embodiment, the following quantization formula can be used:

in,

Indicates the quantized attribute residual, and encoderShiftBit can be set according to requirements, for example, it can be set to 14. Offset represents the parameter that controls rounding, which can be calculated by the formula: offset=1<<(encoderShift-1) during quantization, and the quantization coefficient MF can be obtained by the quantization step size attrQuantStep:

where QP is the quantization parameter. It can be seen that as long as the quantization parameter QP is determined, the quantization formula can be determined.

It can be understood that the quantization step size is negatively correlated with the accuracy of the quantized data, that is, the larger the quantization step size, the lower the accuracy of the quantized data, and the smaller the quantization step size, the higher the accuracy of the quantized data. Specifically, the larger the quantization step size is, the larger the difference between the ignored data will be. In this way, the compression rate of the data will be higher, and the accuracy of the data will be lost during the quantization process. The accuracy of the data obtained after quantization will be higher. The lower the value, the smaller the quantization step size, the smaller the difference between the ignored data. In this way, the compression rate of the data will be lower, and the data will lose less precision during the quantization process, and the data obtained after quantization will be lower. the higher the accuracy. It can be seen from the above calculation formula of the quantization step size that the quantization step size attrQuantStep is positively correlated with the quantization parameter QP. Therefore, the larger the quantization parameter, the lower the accuracy of the quantized data, and the smaller the quantization parameter, the lower the accuracy of the quantized data. higher.

When the quantization coefficient MF is determined by using the quantization parameter QP, in one embodiment, the encoder can determine the MF corresponding to different QPs by looking up a table. Here, for the relationship between the quantization parameter QP and the quantization coefficient MF, reference may be made to Table 1, and Table 1 is a table of quantization coefficients.

Table 1: Quantization coefficient table

QP的值value of QP	MF的值value of MF	QP的值value of QP	MF的值value of MF	QP的值value of QP	MF的值value of MF	QP的值value of QP	MF的值value of MF
00	1638416384	11	1502415024	22	1377713777	33	1263412634
44	1158511585	55	1062410624	66	97429742	77	89338933
88	81928192	99	75127512	1010	68896889	1111	63176317
1212	57935793	1313	53125312	1414	48714871	1515	44674467
1616	40964096	1717	37563756	1818	34443444	1919	31583158
2020	28962896	21twenty one	26562656	22twenty two	24352435	23twenty three	22332233
24twenty four	20482048	2525	18781878	2626	17221722	2727	15791579
2828	14481448	2929	13281328	3030	12181218	3131	11171117
3232	10241024	3333	939939	3434	861861	3535	790790
3636	724724	3737	664664	3838	609609	3939	558558

4040	512512	4141	470470	4242	431431	4343	395395
4444	362362	4545	332332	4646	304304	4747	279279
4848	256256	4949	235235	5050	215215	5151	197197
5252	181181	5353	166166	5454	152152	5555	140140
5656	128128	5757	117117	5858	108108	5959	9999
6060	9191	6161	8383	6262	7676	6363	7070

When quantizing the attribute residual, the encoder can use the quantization parameter QP as an index (the value of QP ranges from 0 to 63), and obtain the corresponding quantization coefficient MF through the above-mentioned quantization coefficient table query, so that the attribute residual can be quantified by MF. quantify.

After completing the quantization of the attribute residual, the encoder can encode the quantized attribute residual into the code stream. The decoding end can decode the quantized attribute residual from the code stream, and can perform inverse quantization on the quantized attribute residual. The inverse quantized attribute residual can be compared with the attribute prediction value of the currently decoded point cloud point. Add up to reconstruct the attribute reconstruction value of the currently decoded point cloud point.

In order to reduce the error between the reconstructed attribute value reconstructed by the decoding end and the real value of the attribute, in one embodiment, the encoding end may perform inverse quantization on the quantized attribute residual after completing the quantization of the attribute residual, and The attribute reconstruction value of the currently coded point cloud point is reconstructed by using the inverse quantized attribute residual and the attribute prediction value of the currently coded point cloud point. As mentioned above, the attribute prediction value of the current point cloud point is calculated according to the attribute reconstruction value of the point cloud point that has been encoded and decoded before the current point cloud point. After encoding and decoding, the attribute reconstruction value of the point cloud point can be reconstructed like the decoding end, and the attribute reconstruction value of the point cloud point can be used to calculate the attribute prediction value of the next point cloud point.

When performing inverse quantization on the quantized attribute residual at the encoding end or the decoding end, in one embodiment, inverse quantization may be performed by the following inverse quantization formula:

in,

Represents the attribute residual after inverse quantization, which can also be called reconstruction residual. decoderShiftBit can be set according to requirements, for example, it can be set to 6; offset represents a parameter that controls rounding, which can be calculated by the formula: offset=1<<(decoderShift-1) during inverse quantization; the inverse quantization coefficient IMF can be Obtained by the quantization step size attrQuantStep:

IMF=(1＜＜decoderShift)×attrQuantStep

See, as long as the quantization parameter QP is determined, the inverse quantization formula can be determined.

When the inverse quantization coefficient IMF is determined by the quantization parameter QP, in one embodiment, the encoding end or the decoding end may determine the IMFs corresponding to different QPs by looking up a table. Here, for the relationship between the quantization parameter QP and the inverse quantization coefficient IMF, reference may be made to Table 2, which is an inverse quantization coefficient table.

Table 2: Inverse quantization coefficient table

QP的值value of QP	IMF的值IMF value	QP的值value of QP	IMF的值IMF value	QP的值value of QP	IMF的值IMF value	QP的值value of QP	IMF的值IMF value
00	6464	11	7070	22	7676	33	8383
44	9191	55	9999	66	108108	77	117117
88	128128	99	140140	1010	152152	1111	166166
1212	181181	1313	197197	1414	215215	1515	235235
1616	256256	1717	279279	1818	304304	1919	332332
2020	362362	21twenty one	395395	22twenty two	431431	23twenty three	470470
24twenty four	512512	2525	558558	2626	609609	2727	664664
2828	724724	2929	790790	3030	861861	3131	939939
3232	10241024	3333	11171117	3434	12181218	3535	13281328
3636	14481448	3737	15791579	3838	17221722	3939	18781878
4040	20482048	4141	22332233	4242	24352435	4343	26562656
4444	28962896	4545	31583158	4646	34443444	4747	37563756
4848	40964096	4949	44674467	5050	48714871	5151	53125312
5252	57935793	5353	63176317	5454	68896889	5555	75127512
5656	81928192	5757	89338933	5858	97429742	5959	1062410624
6060	1158511585	6161	1263412634	6262	1377713777	6363	1502415024

When performing inverse quantization on the quantized attribute residual, the encoding end or the decoding end may use the quantization parameter QP as an index (the value of QP ranges from 0 to 63), and query the inverse quantization coefficient table to obtain the corresponding inverse quantization coefficient. IMF, so that IMF can be used to inverse quantize the quantized attribute residual.

As mentioned earlier, point cloud properties include one or more properties such as color, reflectivity, timestamp, transparency, etc. When encoding and decoding point cloud attributes, different attributes of the point cloud are encoded and decoded separately. For the color property of the point cloud, in one embodiment, the color of the point cloud can be represented on the YUV color space. In one example, if the color of the point cloud is represented in the RGB color space, the color can be converted from the RGB color space to the YUV color space. When the color of the point cloud is represented on the YUV color space, the color of the point cloud can include a luminance channel and a chrominance channel. In this way, when encoding and decoding the color data of the point cloud, the luminance data of the luminance channel and the chrominance data of the chrominance channel of the color of the point cloud can be separately encoded and decoded.

When encoding and decoding the chrominance data of the point cloud, since the chrominance is also a kind of point cloud attribute, the encoding end can use the chroma reconstruction value of the point cloud point that has been encoded and decoded to calculate the current encoded point cloud point. The chrominance prediction value, and the chrominance residual of the currently coded point cloud point can be calculated by using the chrominance real value of the currently coded point cloud point and the chrominance prediction value. After the chrominance residual of the currently encoded point cloud point is calculated, the chrominance residual can be quantized. Specifically, the chrominance residual can be quantized by using the quantization parameter of the chrominance channel.

The quantization parameter of the chrominance channel can be used to quantize the chrominance residual. Specifically, the quantization parameter of the chrominance channel can be used to determine the quantization formula, so that the quantization formula can be used to quantize the chrominance residual. Correspondingly, when performing inverse quantization on the quantized chrominance residual, the quantization parameter of the chrominance channel can also be used to determine an inverse quantization formula, and the quantized chrominance residual can be inversely quantized by using the inverse quantization formula.

In one embodiment, the quantization parameter of the chrominance channel may be obtained by adding the offset of the quantization parameter of the luminance channel and the quantization parameter of the chrominance channel. The quantization parameter of the channel may be denoted as lumaQp, and the offset of the quantization parameter of the chroma channel may be denoted as chromaQpOffset, and the following relationship may be satisfied between the three: chromaQp=lumaQp+chromaQpOffset.

In one embodiment, the offset of the quantization parameter of the chrominance channel can be used as a fixed syntax element to be encoded in the header information of the point cloud attribute. Reference can be made to Table 3. Table 3 is the point cloud attribute provided by the embodiment of the present application. The first example of the header information.

Table 3: The first embodiment of header information of point cloud attributes

The meanings of each syntax element included in the header information of the point cloud attributes in Table 3 are as follows:

1. withColor: color identification, used to indicate whether the point cloud attribute contains color data, its data type is a binary variable, in an example, when the value of withColor is '1', it means that the point cloud attribute contains color data, when A withColor value of '0' indicates that the point cloud attribute does not contain color data.

2. withRef: reflectivity identifier, which is used to indicate whether the point cloud attribute contains reflectivity data. Its data type is a binary variable. In an example, when the value of withRef is '1', it means that the point cloud attribute contains reflectivity. Data, when the withRef value is '0', it means that the point cloud attribute does not contain reflectivity data.

3. cross_component_pred: secondary prediction of attribute residual, its data type is a binary variable. In an example, when the value of cross_component_pred is '1', it means that secondary prediction of attribute residual is allowed, when the value of cross_component_pred is '0' ', it means that secondary prediction of attribute residuals is not allowed.

4. maxNumOfNeighbour: The maximum number of neighbor points to be searched, whose data type is an unsigned integer, is used to control the search range of neighbor candidate points and the number of points cached by hardware during attribute prediction. In an example, maxNumOfNeighbours should not be greater than 1024.

5. maxNumOfPredictNeighbours: The maximum number of neighbors selected for prediction, whose data type is an unsigned integer, is used to limit the number of neighbors selected during attribute prediction. In one example, maxNumOfPredictNeighbours should not be greater than 16.

6. numOflevelOfDetail: the number of LoD layers, whose data type is an unsigned integer, used to control the number of LOD layers divided during attribute prediction. In an example, numOflevelOfDetail should not be greater than 32.

7. intraLodFlag: LoD intra-layer prediction flag, its data type is a binary variable, which is used to control whether to enable intra-layer prediction. When the value of intraLodFlag is '1', intra-layer prediction is enabled, and when the value of intraLodFlag is '0' , turns off intra-layer prediction.

8. Transform: The attribute transformation algorithm flag, whose data type is a binary variable, is used to control whether to use wavelet transform to encode attributes. When the value of Transform is '1', wavelet transform is used, and when the value of Transform is '0' , which encodes the attribute using the prediction method.

9. chromaQpOffset: the offset of the quantization parameter of the chroma channel, whose data type is an unsigned integer, used to control the quantization parameter chromaQp of the chroma channel, chromaQp=attribute_qp+chromaQpOffset, and the quantization parameter lumaQp=attribute_qp of the luminance channel.

10. outputBitDepth: The attribute output bit depth, whose data type is an unsigned integer, is used to control the attribute output bit depth.

It can be known from the first embodiment of the header information of the point cloud attribute that the offset of the quantization parameter of the chrominance channel, as one of the syntax elements, is fixed to be encoded into the code stream. However, the point cloud attribute does not necessarily contain color data. When the point cloud attribute does not contain color data, since the point cloud color does not need to be encoded and decoded, it is also not necessary to use the offset of the quantization parameter of the chrominance channel. , if the offset of the quantization parameter of the chrominance channel is still encoded into the code stream, it will cause a certain bit waste.

To solve this problem, an embodiment of the present application provides a point cloud attribute decoding method. Referring to FIG. 1, FIG. 1 is a first flowchart of the point cloud attribute decoding method provided by the embodiment of the present application, and the method includes the following steps:

S102. Decode the color identification of the point cloud attribute from the code stream.

S104A. When the color identifier indicates that the point cloud attribute contains color data, decode the offset of the quantization parameter of the chrominance channel from the code stream.

S106A. Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel.

S108A. Perform inverse quantization on the chrominance residual corresponding to the chrominance channel by using the quantization parameter of the chrominance channel.

S104B. When the color identifier indicates that the point cloud attribute does not contain color data, determine that there is no offset of the quantization parameter of the chrominance channel in the code stream.

It can be explained from the coding side first. The encoding end can obtain the point cloud to be encoded. Here, the point cloud to be encoded can be any point cloud. In one example, the point cloud to be encoded may be a point cloud obtained by scanning a lidar. In one example, the point cloud to be encoded may be a point cloud obtained by three-dimensional reconstruction using an image. Of course, the point cloud to be encoded may also be obtained by Point clouds obtained by other means.

The point cloud attributes of the point cloud to be encoded can have various attributes, but they do not necessarily include color attributes. For example, if the point cloud to be encoded is a point cloud scanned by a lidar, since the lidar cannot obtain color information, the point cloud attribute of the point cloud to be encoded may not include color data. For another example, if the point cloud to be encoded is a point cloud obtained by three-dimensional reconstruction of an image, since the image includes color information, the point cloud attribute of the point cloud to be encoded may include color data.

The encoding end can generate a corresponding color identification according to whether the point cloud attribute of the point cloud to be encoded includes color data, and can encode the generated color identification into the code stream. Here, the color identification can be used to indicate whether the point cloud attribute of the point cloud to be encoded includes color data. In one example, the color identifier can be the syntax element withColor in the point cloud attribute header information, then when the point cloud attribute of the point cloud to be encoded includes color data, a color identifier withColor with a value of '1' can be generated. When the point cloud attribute of the point cloud does not include color data, a color flag withColor with a value of '0' can be generated.

If the generated color identifier indicates that the point cloud attribute of the point cloud to be encoded includes color data (for example, withColor=1), the color data of the point cloud to be encoded needs to be encoded and decoded, and the offset of the quantization parameter of the chrominance channel needs to be used , therefore, the encoder can encode the offset of the quantization parameter of the chroma channel to the code stream. If the generated color identifier indicates that the point cloud attribute of the point cloud to be encoded does not include color data (for example, withColor=0), the offset of the quantization parameter of the chrominance channel will not be used in the subsequent encoding and decoding process. Therefore, The encoding end may not encode the offset of the quantization parameter of the chrominance channel, thereby saving bits.

When color-coding the point cloud, the encoder can calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel. Specifically, as described above, the encoding end may add the quantization parameter chromaQpOffset of the chrominance channel and the quantization parameter lumaQp of the luminance channel to calculate the quantization parameter chromaQp of the chrominance channel. After calculating the quantization parameter of the chrominance channel, the quantization parameter can be used to quantize the chrominance residual, and the quantized chrominance residual can be encoded into the code stream. Here, the chrominance residual may be obtained by the coding end using the difference between the actual chrominance value of the currently coded point cloud point and the chrominance predicted value of the currently coded point cloud point, and the chrominance prediction of the currently coded point cloud point The value can be calculated by using the chroma reconstruction value of the point cloud point that has been encoded and decoded.

For the decoding end, the decoding end can first decode the code stream to obtain the color identification of the point cloud attribute. If the color identification indicates that the point cloud attribute of the point cloud to be encoded includes color data (for example, withColor=1), it means that the encoding end The offset of the quantization parameter of the chrominance channel is encoded into the code stream, so that the decoding end can decode the offset of the quantization parameter of the chrominance channel from the code stream. If it is determined that the color identifier indicates that the point cloud attribute of the point cloud to be encoded does not include color data (for example, withColor=0), it means that the encoding end does not encode the offset of the quantization parameter of the chroma channel to the code stream, and the decoding end can determine There is no offset of the quantization parameter of the chrominance channel in the code stream, so there is no need to decode the offset of the quantization parameter of the chrominance channel.

After decoding the offset of the quantization parameter of the chrominance channel from the code stream, the decoding end may calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel. Here, the calculation method is the same as the above, that is, the offset chromaQpOffset of the quantization parameter of the chroma channel and the quantization parameter lumaQp of the luminance channel can be added to obtain the quantization parameter chromaQp of the chroma channel. After the quantization parameter of the chrominance channel is calculated, the quantization parameter can be used to inversely quantize the quantized chrominance residual at the coding end decoded from the code stream, so that the inverse quantized chrominance residual can be used to reconstruct the current The chrominance value of the decoded point cloud point, specifically, the chroma residual error after inverse quantization can be added to the chroma prediction value of the currently decoded point cloud point, so as to obtain the chroma reconstruction of the currently decoded point cloud point value.

Reference can be made to Table 4. Table 4 is the second example of the header information of the point cloud attribute provided by the embodiment of the present application.

Table 4: Second embodiment of header information of point cloud attributes

It can be seen from Table 4 that the syntax element chromaQpOffset is located in the execution statement of the if statement. Therefore, the encoder will encode the syntax element chromaQpOffset only if the condition of withColor=1 is satisfied. When withColor=0, the encoder will not encode the chromaQpOffset, saving up bits.

As mentioned above, chromaQpOffset is the offset of the quantization parameter of the chroma channel, which can be used to calculate the quantization parameter chromaQp of the chroma channel. Specifically, it can be calculated by the following formula:

chromaQp=attribute_qp+chromaQpOffset;

lumaQp=attribute_qp.

It can be seen that the quantization parameter chromaQp of the chrominance channel is obtained by adding the offset chromaQpOffset of the quantization parameter of the chrominance channel and the quantization parameter lumaQp of the luminance channel, and in the above embodiment of the header information of the point cloud attribute, the data of chromaQpOffset The type is ue(v), and ue(v) represents the syntax element of the unsigned integer exponent Columbus encoding. Therefore, the result of adding chromaQpOffset and lumaQp chromaQp can only be greater than or equal to lumaQp, that is, the accuracy of the point cloud chroma after encoding and decoding is at most only The accuracy is the same as that of luminance, which cannot meet the need for higher accuracy of the chromaticity of the point cloud.

In response to the above problem, in one embodiment, the data type of chromaQpOffset can be adjusted to a signed number, for example, the data type of chromaQpOffset can be set to se(v), where se(v) represents a signed integer exponential Golomb coding syntax element , so, chromaQpOffset can be a negative number, the result of adding chromaQpOffset and lumaQp chromaQp can be smaller than lumaQp, the quantization parameter of chrominance channel can be adjusted down, which expands the adjustable range of precision of point cloud chrominance data. In one embodiment, the offsets of the quantization parameters of the chrominance channel may be binarized using signed exponential Golomb.

Reference can be made to Table 5. Table 5 is the third example of the header information of the point cloud attribute provided by the embodiment of the present application.

Table 5: The third embodiment of header information of point cloud attributes

In Table 5, the data type of chromaQpOffset is changed to se(v), which is a signed number. Therefore, the quantization parameters of the chroma channel can be lowered, and the encoded and decoded point cloud chroma can retain higher precision.

chromaQpOffset is the offset of the quantization parameter of the chrominance channel, but in some color representations, the color may include multiple chrominance channels, for example, may include a first chrominance channel and a second chrominance channel. In one example, if the color of the point cloud is represented by the YUV format, the first chrominance channel and the second chrominance channel may be a U chrominance channel and the other a V chrominance channel. In one example, if the color of the point cloud is represented by the YCbCr format, the first chrominance channel and the second chrominance channel may be a Cr chrominance channel and a Cb chrominance channel. In one example, if the color of the point cloud is represented by the YPbPr format, the first chrominance channel and the second chrominance channel may be a Pr chrominance channel and a Pb chrominance channel. Of course, there are other color spaces or formats that can represent colors, and we will not give examples here.

When there are multiple chroma channels for the color of the point cloud, and the offset of the quantization parameter of the chroma channel is only one, the offset of the quantization parameter of the chroma channel will be shared by multiple chroma channels, so that in the point cloud During color encoding and decoding, the chroma residuals corresponding to each chroma channel will be quantized using the same quantization parameters, which results in insufficient flexibility in point cloud color encoding and decoding. For example, in an example, if it is desired to use higher compression strength for the chrominance residual corresponding to the Cr chrominance channel and retain higher precision for the chrominance residual of the Cb chrominance channel, then only one chrominance Such expectations will be difficult to achieve when offsetting the channel's quantization parameters.

In order to solve the above problem, in one embodiment, the encoding end can encode the offset of the quantization parameter corresponding to the chrominance channel to the code stream for different chrominance channels, and can for each chrominance channel, according to its The offset of the corresponding quantization parameter is used to calculate the corresponding quantization parameter, so that the chrominance residual corresponding to different chrominance channels can be quantized by using different quantization parameters during quantization. Correspondingly, the decoding end can decode the offset of the quantization parameter corresponding to each chrominance channel from the code stream, and can use the offset of the corresponding quantization parameter to calculate the corresponding quantization parameter for each chrominance channel. , so that the chroma residuals of different chroma channels can be inversely quantized using different quantization parameters.

Reference may be made to Table 6. Table 6 is a fourth example of the header information of the point cloud attribute provided by this embodiment of the present application.

Table 6: Fourth embodiment of header information of point cloud attributes

In the example shown in Table 6, the offset of the quantization parameter of the chrominance channel includes the offset of the quantization parameter of the Cb chrominance channel chromaQpOffsetCb and the offset of the quantization parameter of the Cr chrominance channel chromaQpOffsetCr, then the encoding end is in When encoding the offsets of the quantization parameters of the chrominance channel, both the offsets chromaQpOffsetCb and chromaQpOffsetCr of the quantization parameters of the two chrominance channels may be encoded into the code stream. Correspondingly, when the decoding end decodes the offsets of the quantization parameters of the chrominance channel from the codestream, the offsets chromaQpOffsetCb and chromaQpOffsetCr of the quantization parameters of the two chrominance channels can also be decoded from the codestream.

Using the offset chromaQpOffsetCb of the quantization parameter of the Cb chrominance channel, the quantization parameter chromaQpCb of the Cb chrominance channel can be calculated. Specifically, it can be calculated by the following formula:

chromaQpCb=attribute_qp+chromaQpOffsetCb;

lumaQp=attribute_qp.

Using the offset chromaQpOffsetCr of the quantization parameter of the Cr chrominance channel, the quantization parameter chromaQpCr of the Cr chrominance channel can be calculated. Specifically, it can be calculated by the following formula:

chromaQpCr=attribute_qp+chromaQpOffsetCr;

lumaQp=attribute_qp.

Since different chrominance channels have their corresponding quantization parameters, the encoding end can use the quantization parameters corresponding to the chrominance channel itself when quantizing the chrominance residuals of different chrominance channels; When inverse quantizing the chroma residuals of different chroma channels, the terminal can use the quantization parameters corresponding to the chroma channels themselves, which improves the flexibility of point cloud color coding and decoding.

Considering that when different chroma channels have their corresponding offsets of quantization parameters, the number of syntax elements to be encoded into the code stream increases, and the number of bits consumed will also increase. If the offsets of the quantization parameters corresponding to the chrominance channels are all preset values, the encoder can encode a switch flag corresponding to the closed state into the code stream, and no longer encode the offsets of the quantization parameters of each chrominance channel. . Correspondingly, the decoding end can decode the switch identification from the code stream. Since the switch identification corresponds to the off state, the decoding end can determine that there is no offset of the quantization parameter of each chroma channel in the code stream, and can directly determine The offsets of the quantization parameters of each chrominance channel are all preset values.

It can be seen that by setting the syntax element of the switch identifier, when the offsets of the quantization parameters corresponding to each chroma channel are all preset values, only one switch identifier corresponding to the off state can be encoded without encoding the quantization of each chroma channel. The offset of the parameter, thus saving bits. Here, the preset value can be set according to actual requirements. In an example, the preset value can be 0, that is, when both chromaQpOffsetCb and chromaQpOffsetCr are 0, the encoder can encode the switch identifier corresponding to the off state to the code stream.

If the offsets of the quantization parameters corresponding to each chrominance channel are not all preset values, that is, there are offsets of the quantization parameters of the chrominance channels that are not preset values, the encoding end can encode a corresponding open state. The switch is identified to the code stream, and the offsets of the quantization parameters corresponding to each chrominance channel are also encoded into the code stream. Correspondingly, the decoding end can decode the code stream to obtain the switch identifier. Since the switch identifier corresponds to the ON state, the decoding end can continue to decode the code stream to obtain the offsets of the quantization parameters of each chrominance channel.

Reference may be made to Table 7. Table 7 is the fifth embodiment of the header information of the point cloud attribute provided by the embodiment of the present application.

Table 7: Fifth embodiment of header information of point cloud attributes

In the above Table 7, the syntax element chromaQpOffsetEnableFlag may be the switch flag. In an example, chromaQpOffsetEnableFlag=1 may correspond to an on state, and chromaQpOffsetEnableFlag=0 may correspond to an off state. Thus, when chromaQpOffsetEnableFlag=1, the encoder can set the chromaQpOffsetEnableFlag Encode into the code stream, and encode the offsets chromaQpOffsetCb and chromaQpOffsetCr of the quantization parameters of the two chroma channels into the code stream; when chromaQpOffsetEnableFlag=0, the encoder can encode the chromaQpOffsetEnableFlag into the code stream, and can not encode chromaQpOffsetCb and chromaQpOffsetCb and chromaQpOffsetCr.

Referring to Table 7, it can be seen that in the encoding and decoding process, the encoding end can first encode the color flag withColor to the code stream. If the color flag withColor=1, the encoding end will encode the switch flag chromaQpOffsetEnableFlag, otherwise, if the color flag withColor=0, then The encoding end does not need the encoding switch flag chromaQpOffsetEnableFlag. Correspondingly, the decoding end can decode the color flag withColor from the code stream. Only when the color flag withColor=1, the decoding end will continue to decode the switch flag chromaQpOffsetEnableFlag from the code stream. If the color flag withColor=0, the decoding end does not need to decode. The switch flags chromaQpOffsetEnableFlag.

As can be seen from the foregoing, when the quantization parameter of the chrominance channel is used to quantize or inversely quantize the chrominance residual, the quantization parameter of the chrominance channel can be used to determine the quantization formula or the inverse quantization formula. Specifically, when determining the quantization formula, the encoder can query the corresponding quantization coefficient MF in the quantization coefficient table (Table 1) according to the quantization parameter chromaQp of the chroma channel, and when determining the inverse quantization formula, the encoder or decoder can The corresponding inverse quantization coefficient IMF is queried in the inverse quantization coefficient table (Table 2) according to the quantization parameter chromaQp of the chrominance channel. Here, regardless of whether the quantization coefficient MF or the inverse quantization coefficient IMF is queried, the value range of the quantization parameter chromaQp of the chrominance channel is 0-63. However, in some cases, the value of chromaQp may fall outside this range, resulting in data overflow.

In view of the above-mentioned problem of data overflow, in an embodiment, after calculating the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel, the encoding end or the decoding end can calculate the quantization parameter of the chrominance channel. It is limited between the minimum quantization parameter corresponding to the chrominance channel and the maximum quantization parameter corresponding to the chrominance channel, and the quantization parameter of the chrominance channel after the limiting operation is used to quantize the chrominance residual. Here, the minimum quantization parameter corresponding to the chrominance channel and the maximum quantization parameter corresponding to the chrominance channel can be set according to the actual situation. The minimum quantization parameter of can be 0, and the maximum quantization parameter corresponding to the chrominance channel can be 63. Of course, 0 and 63 here are only exemplary values.

In one embodiment, the value range of the quantization parameter of the chroma channel may be independent of the value range of the quantization parameter of the luma channel, that is, the value range of chromaQp and the value range of lumaQp may be the same or different. If the minimum quantization parameter corresponding to the chroma channel is recorded as chromaMinQp, the maximum quantization parameter corresponding to the chroma channel is recorded as chromaMaxQp, the minimum quantization parameter corresponding to the luma channel is recorded as lumaMinQp, and the maximum quantization parameter corresponding to the luma channel is recorded as lumaMaxQp, then chromaMinQp Can be the same or different from lumaMinQp and can be the same or different from chromaMaxQp and lumaMaxQp.

Limiting the quantization parameters of the chroma channels can be implemented in various ways. In one embodiment, a clip operation can be performed on the calculated quantization parameters of the chrominance channel, and the following formula can be referred to:

chromaQp=clip3(chromaMinQp, chromaMaxQp, attribute_qp+chromaQpOffset);

lumaQp=attribute_qp.

In the above formula, the meaning of clip3 is to truncate the third parameter (attribute_qp+chromaQpOffset) between the first parameter (chromaMinQp) and the second parameter (chromaMaxQp), that is, if the third parameter is smaller than the first parameter parameter, the output is the first parameter, if the third parameter is greater than the second parameter, the output is the second parameter, if the third parameter is between the first parameter and the second parameter, that is, the first parameter If the three parameters are greater than or equal to the first parameter and less than or equal to the second parameter, the third parameter is output.

In an implementation manner, if there are multiple quantization parameters of the chrominance channel, the limiting operation may be performed separately on the quantization parameters of each chrominance channel. For example, if the quantization parameters of the chroma channel include chromaQpCb and chromaQpCr, the clip operation can be performed on chromaQpCb and chromaQpCr respectively, and the following formula can be referred to:

chromaQpCb=clip3(chromaMinQp, chromaMaxQp, attribute_qp+chromaQpOffsetCb);

chromaQpCr=clip3(chromaMinQp, chromaMaxQp, attribute_qp+chromaQpOffsetCr);

lumaQp=attribute_qp.

By limiting the quantization parameter of the chroma channel to be between the minimum quantization parameter and the maximum quantization parameter before using the quantization parameter of the chroma channel to quantize the chroma residual, the occurrence of data overflow can be prevented, and the subsequent quantization of the chroma residual quantification guarantees.

Referring to FIG. 2 below, FIG. 2 is a first flowchart of a point cloud attribute encoding method provided by an embodiment of the present application, and the method includes:

S202. Obtain a point cloud to be encoded.

S204. Generate a color identifier for indicating whether the point cloud attribute of the point cloud to be encoded contains color data, and encode the color identifier into a code stream.

S206A. When the color identifier indicates that the point cloud attribute of the point cloud to be encoded contains color data, encode the offset of the quantization parameter of the chrominance channel to the code stream.

S208A. Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel.

S210A. Quantize the chrominance residual corresponding to the chrominance channel by using the quantization parameter of the chrominance channel.

S206B, when the color identifier indicates that the point cloud attribute of the point cloud to be encoded does not contain color data, do not encode the offset of the quantization parameter of the chrominance channel.

Optionally, the offset of the quantization parameter of the chrominance channel includes: the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel.

Optionally, one of the first chrominance channel and the second chrominance channel is a Cb chrominance channel, and the other is a Cr chrominance channel.

Optionally, the offset of the quantization parameter of the encoded chrominance channel to the code stream includes:

If either the offset of the quantization parameter of the first chrominance channel or the offset of the quantization parameter of the second chrominance channel is not a preset value, encode the switch flag corresponding to the ON state into the code stream, and The offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are encoded into the code stream.

Optionally, the method further includes:

If the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are both preset values, encode the switch flag corresponding to the off state to the code stream, and do not encode the The offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel.

Optionally, before using the quantization parameter of the chrominance channel to quantize the chrominance residual corresponding to the chrominance channel, the method further includes:

The quantization parameter of the chrominance channel is limited between the minimum quantization parameter corresponding to the chrominance channel and the maximum quantization parameter corresponding to the chrominance channel.

Optionally, the minimum quantization parameter corresponding to the chrominance channel is the same or different from the minimum quantization parameter corresponding to the luminance channel, and the maximum quantization parameter corresponding to the chrominance channel is the same or different from the maximum quantization parameter corresponding to the luminance channel.

Optionally, the offset of the quantization parameter of the chrominance channel is a signed number.

Optionally, the offset of the quantization parameter of the chrominance channel is binarized by using signed exponential Golomb.

Optionally, the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.

Optionally, the method further includes:

The chrominance residual corresponding to the quantized chrominance channel is encoded into the code stream.

Optionally, the chrominance residual corresponding to the chrominance channel is obtained by making a difference between the actual chrominance value corresponding to the chrominance channel of the currently encoded point cloud point and the predicted chrominance value corresponding to the chrominance channel. .

For the various implementation manners of the point cloud attribute encoding method provided by the above embodiments of the present application, the specific implementation thereof may refer to the relevant descriptions in the foregoing, which will not be repeated here.

Referring to FIG. 3 below, FIG. 3 is a second flowchart of a point cloud attribute decoding method provided by an embodiment of the present application, and the method includes:

S302: Decode the offsets of the quantization parameters corresponding to each of the multiple chrominance channels from the code stream.

S304. For each chrominance channel in the plurality of chrominance channels, calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel.

S306. For each chrominance channel, perform inverse quantization on the chrominance residual corresponding to the chrominance channel by using the quantization parameter of the chrominance channel.

Optionally, the plurality of chrominance channels include two chrominance channels.

Optionally, the two chrominance channels include: a Cb chrominance channel and a Cr chrominance channel.

Optionally, the offsets of the quantization parameters corresponding to each of the decoding multiple chrominance channels from the code stream include:

Decode the color identification of point cloud attributes from the code stream;

If the color identifier indicates that the point cloud attribute contains color data, the offsets of the quantization parameters corresponding to each of the plurality of chrominance channels are decoded from the code stream.

Optionally, the method further includes:

If the color identifier indicates that the point cloud attribute does not contain color data, it is determined that there is no offset of the quantization parameter corresponding to each of the plurality of chrominance channels in the code stream.

Decode the switch ID from the code stream;

If the switch flag corresponds to an on state, the offsets of the quantization parameters corresponding to each of the multiple chrominance channels are decoded from the code stream.

Optionally, the method further includes:

If the switch identifier corresponds to an off state, it is determined that there is no offset of the quantization parameter corresponding to each of the plurality of chrominance channels in the code stream.

Optionally, the method further includes:

If the switch identifier corresponds to an off state, it is determined that the offsets of the quantization parameters corresponding to the plurality of chrominance channels are all preset values.

Optionally, before using the quantization parameter of the chrominance channel to perform inverse quantization on the chrominance residual corresponding to the chrominance channel, the method further includes:

Optionally, the inverse quantized chroma residual corresponding to the chroma channel is used to calculate the chroma reconstruction value corresponding to the chroma channel of the currently decoded point cloud point.

Optionally, the chroma reconstruction value corresponding to the chroma channel is the chroma residual corresponding to the inverse quantized chroma channel and the chroma prediction value corresponding to the chroma channel of the currently decoded point cloud point. obtained by adding.

For the various implementation manners of the point cloud attribute decoding method provided by the above embodiments of the present application, the specific implementation thereof may refer to the relevant descriptions in the foregoing, which will not be repeated here.

In the point cloud attribute encoding and decoding method provided by the embodiments of the present application, syntax elements of offsets of respective quantization parameters are configured for each chroma channel, so that different chroma channels have their corresponding quantization parameters, and different chroma The chroma residual of the channel can be quantized or inverse quantized by different quantization parameters, which improves the flexibility of point cloud color coding and decoding.

Referring to FIG. 4 below, FIG. 4 is a second flowchart of a point cloud attribute encoding method provided by an embodiment of the present application, and the method includes:

S402: Encode the offsets of the quantization parameters corresponding to each of the multiple chrominance channels into a code stream.

S404. For each chrominance channel in the plurality of chrominance channels, calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel.

S406. For each chrominance channel, use the quantization parameter of the chrominance channel to quantize the chrominance residual corresponding to the chrominance channel.

Optionally, encoding the offsets of the quantization parameters corresponding to the multiple chrominance channels into the code stream includes:

Generate a corresponding color mark according to whether the point cloud attribute of the point cloud to be encoded contains color data, and encode the color mark to the code stream;

If the color identifier indicates that the point cloud attribute of the point cloud to be encoded includes color data, the offsets of the quantization parameters corresponding to the multiple chrominance channels are encoded into the code stream.

Optionally, the method further includes:

If the color identifier indicates that the point cloud attribute of the to-be-encoded point cloud does not contain color data, the offset of the quantization parameter corresponding to each of the plurality of chrominance channels is not encoded.

If any of the offsets of the quantization parameters corresponding to the multiple chroma channels is not a preset value, encode the switch flag corresponding to the on state to the code stream, and quantize the corresponding quantization parameters of the multiple chroma channels The offset of the parameter is encoded into the codestream.

Optionally, the method further includes:

If the offsets of the quantization parameters corresponding to the multiple chrominance channels are all preset values, encode the switch flag corresponding to the off state to the code stream, and do not encode the offsets of the quantization parameters corresponding to the multiple chrominance channels. shift.

Optionally, the method further includes:

The chrominance residuals corresponding to each of the quantized chrominance channels are encoded into the code stream.

Reference may be made to FIG. 5 below. FIG. 5 is a third flowchart of a point cloud attribute decoding method provided by an embodiment of the present application, and the method includes:

S502. Decode the offset of the quantization parameter of the chrominance channel from the code stream.

Wherein, the offset of the quantization parameter of the chrominance channel is a signed number.

S504. Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel.

S506. Perform inverse quantization on the chrominance residual corresponding to the chrominance channel by using the quantization parameter of the chrominance channel.

Optionally, the offset of the quantization parameter of the decoded chrominance channel from the code stream includes:

Decode the switch ID from the code stream;

If the switch identifier corresponds to an on state, the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are decoded from the code stream.

Optionally, the method further includes:

If the switch flag corresponds to an off state, it is determined that the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel do not exist in the code stream.

Optionally, the method further includes:

If the switch flag corresponds to an off state, it is determined that the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are both preset values.

Decode the color identification of point cloud attributes from the code stream;

If the color flag indicates that the point cloud attribute contains color data, the offset of the quantization parameter of the chrominance channel is decoded from the code stream.

Optionally, the method further includes:

If the color identifier indicates that the point cloud attribute does not contain color data, it is determined that the offset of the quantization parameter of the chrominance channel does not exist in the code stream.

Optionally, the color identifier is decoded from the code stream first, and if the color identifier indicates that the point cloud attribute contains color data, then the switch identifier is decoded from the code stream.

In the point cloud attribute encoding and decoding method provided by the embodiment of the present application, the offset of the quantization parameter of the chrominance channel is a signed number. Therefore, by adjusting the offset of the quantization parameter of the chrominance channel, the quantization of the chrominance channel can be The value of the parameter is lowered to expand the adjustable range of the precision of the point cloud chromaticity data.

Referring to FIG. 6 below, FIG. 6 is a third flowchart of a point cloud attribute encoding method provided by an embodiment of the present application, and the method includes:

S602. Encode the offset of the quantization parameter of the chrominance channel into a code stream.

S604. Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel.

S606. Quantize the chrominance residual corresponding to the chrominance channel by using the quantization parameter of the chrominance channel.

Optionally, encoding the offset of the quantization parameter of the chrominance channel into the code stream includes:

Optionally, the method further includes:

If the color identifier indicates that the point cloud attribute of the point cloud to be encoded contains color data, the offset of the quantization parameter of the chrominance channel is encoded into the code stream.

Optionally, the method further includes:

If the color identifier indicates that the point cloud attribute of the point cloud to be encoded does not contain color data, the offset of the quantization parameter of the chrominance channel is not encoded.

Optionally, the color identifier is encoded into the code stream first, and if the color identifier indicates that the point cloud attribute contains color data, then the switch identifier is encoded into the code stream.

Optionally, the method further includes:

Referring to FIG. 7 below, FIG. 7 is a schematic structural diagram of a point cloud attribute decoding device provided by an embodiment of the present application, and the device includes:

A processor 710 and a memory 720 storing a computer program, the processor implements the following steps when executing the computer program:

Decode the color identification of point cloud attributes from the code stream;

Optionally, when the processor decodes the offset of the quantization parameter of the chrominance channel from the code stream, it is used for:

Decode the switch ID from the code stream;

Optionally, the processor is also used for:

Before using the quantization parameter of the chrominance channel to perform inverse quantization on the chrominance residual corresponding to the chrominance channel, the quantization parameter of the chrominance channel is limited to the minimum quantization parameter corresponding to the chrominance channel and the between the maximum quantization parameters corresponding to the chrominance channels.

For the various implementation manners of the point cloud attribute decoding apparatus provided in the above embodiments of the present application, for the specific implementation, reference may be made to the relevant descriptions above, which will not be repeated here.

The point cloud attribute encoding and decoding device provided in the embodiment of the present application can encode the offset of the quantization parameter of the chrominance channel only when the point cloud attribute of the point cloud to be encoded includes color data, and can encode the offset of the quantization parameter of the chrominance channel only when the point cloud attribute of the point cloud to be encoded contains color data, and the point cloud attribute of the point cloud to be encoded The offsets of the quantization parameters of the chroma channels may not be encoded when color data is not included, thereby saving bits.

Referring to FIG. 8 below, FIG. 8 is a schematic structural diagram of a point cloud attribute encoding device provided by an embodiment of the present application, and the device includes:

A processor 810 and a memory 820 storing a computer program that implements the following steps when executing the computer program:

Get the point cloud to be encoded;

Optionally, when encoding the offset of the quantization parameter of the chrominance channel to the code stream, the processor is used for:

Optionally, the processor is also used for:

Before using the quantization parameter of the chrominance channel to quantize the chrominance residual corresponding to the chrominance channel, limit the quantization parameter of the chrominance channel to the minimum quantization parameter corresponding to the chrominance channel and the chrominance channel. between the maximum quantization parameters corresponding to the chroma channels.

Optionally, the processor is also used for:

For the various implementation manners of the point cloud attribute encoding apparatus provided in the above embodiments of the present application, reference may be made to the relevant descriptions in the foregoing for the specific implementation, which will not be repeated here.

The embodiment of the present application also provides a point cloud attribute decoding device, the structure of which can be referred to FIG. 7 , the device includes: a processor and a memory storing a computer program, and the processor implements the following steps when executing the computer program:

Optionally, when the processor decodes the offsets of the quantization parameters corresponding to each of the multiple chrominance channels from the code stream, it is used for:

Decode the color identification of point cloud attributes from the code stream;

Optionally, the processor is also used for:

Decode the switch ID from the code stream;

Optionally, the processor is also used for:

In the point cloud attribute encoding and decoding device provided by the embodiment of the present application, syntax elements of offsets of respective quantization parameters are configured for each chroma channel, so that different chroma channels have their corresponding quantization parameters, and different chroma The chroma residual of the channel can be quantized or inverse quantized by different quantization parameters, which improves the flexibility of point cloud color coding and decoding.

An embodiment of the present application also provides a point cloud attribute encoding device, the structure of which can be referred to FIG. 8 , the device includes: a processor and a memory storing a computer program, and the processor implements the following steps when executing the computer program:

Optionally, when the processor encodes the offsets of the quantization parameters corresponding to each of the multiple chrominance channels into the code stream, it is used for:

Optionally, the processor is also used for:

Decode the switch ID from the code stream;

Optionally, the processor is also used for:

Decode the color identification of point cloud attributes from the code stream;

Optionally, the processor is also used for:

In the point cloud attribute encoding and decoding device provided by the embodiment of the present application, the offset of the quantization parameter of the chrominance channel is a signed number. Therefore, by adjusting the offset of the quantization parameter of the chrominance channel, the quantization of the chrominance channel can be The value of the parameter is lowered to expand the adjustable range of the precision of the point cloud chromaticity data.

Optionally, when the processor encodes the offset of the quantization parameter of the chrominance channel into the code stream, it is used for:

Optionally, the processor is also used for:

For the various implementation manners of the point cloud attribute encoding apparatus provided in the above embodiments of the present application, the specific implementation thereof may refer to the relevant descriptions in the foregoing, which will not be repeated here.

Embodiments of the present application further provide a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, any one of the point cloud attribute decoding methods provided by the embodiments of the present application is implemented .

Embodiments of the present application further provide a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, any one of the point cloud attribute encoding methods provided by the embodiments of the present application is implemented .

Various implementations are provided above for each protection subject. On the basis of no conflict or contradiction, those skilled in the art can freely combine various implementations according to the actual situation, thereby forming various technical solutions. . However, this application document is limited in space and cannot describe all the technical solutions obtained by combination, but it can be understood that these technical solutions that cannot be developed also belong to the scope disclosed in the embodiments of this application.

Embodiments of the present application may take the form of a computer program product implemented on one or more storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having program code embodied therein. Computer-usable storage media includes permanent and non-permanent, removable and non-removable media, and storage of information can be accomplished by any method or technology. Information may be computer readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), Flash Memory or other memory technology, Compact Disc Read Only Memory (CD-ROM), Digital Versatile Disc (DVD) or other optical storage, Magnetic tape cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission medium that can be used to store information that can be accessed by a computing device.

It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. The terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion such that a process, method, article or device comprising a list of elements includes not only those elements, but also other not expressly listed elements, or also include elements inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

The methods and devices provided by the embodiments of the present invention have been described in detail above. The principles and implementations of the present invention are described with specific examples in this paper. The descriptions of the above embodiments are only used to help understand the methods of the present invention and its implementation. At the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. To sum up, the content of this description should not be construed as a limitation to the present invention. .

Claims

A method for decoding point cloud attributes, comprising:

Decode the color identification of point cloud attributes from the code stream;

When the color identifier indicates that the point cloud attribute contains color data, decoding the offset of the quantization parameter of the chrominance channel from the code stream;

Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

Perform inverse quantization on the chrominance residual corresponding to the chrominance channel by using the quantization parameter of the chrominance channel;

When the color identifier indicates that the point cloud attribute does not contain color data, it is determined that there is no offset of the quantization parameter of the chrominance channel in the code stream.
The method according to claim 1, wherein the offset of the quantization parameter of the chrominance channel comprises: the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel shift.
The method according to claim 2, wherein one of the first chrominance channel and the second chrominance channel is a Cb chrominance channel, and the other is a Cr chrominance channel.
The method according to claim 2, wherein the decoding the offset of the quantization parameter of the chrominance channel from the code stream comprises:

Decode the switch ID from the code stream;

If the switch identifier corresponds to an on state, the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are decoded from the code stream.
The method according to claim 4, wherein the method further comprises:

If the switch flag corresponds to an off state, it is determined that the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel do not exist in the code stream.
The method according to claim 4, wherein the method further comprises:

If the switch flag corresponds to an off state, it is determined that the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are both preset values.
The method according to any one of claims 1-6, wherein before performing inverse quantization on the chrominance residual corresponding to the chrominance channel by using the quantization parameter of the chrominance channel, the method further comprises: :

The quantization parameter of the chrominance channel is limited between the minimum quantization parameter corresponding to the chrominance channel and the maximum quantization parameter corresponding to the chrominance channel.
The method according to claim 7, wherein the minimum quantization parameter corresponding to the chrominance channel and the minimum quantization parameter corresponding to the luminance channel are the same or different, and the maximum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel. The maximum quantization parameter is the same or different.
The method according to any one of claims 1-8, wherein the offset of the quantization parameter of the chrominance channel is a signed number.
The method according to claim 9, wherein the offset of the quantization parameter of the chrominance channel is binarized by using a signed exponential Golomb.
The method according to any one of claims 1-10, wherein the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.
The method according to any one of claims 1-11, wherein the inverse quantized chroma residual corresponding to the chroma channel is used to calculate the chroma residual corresponding to the chroma channel of the currently decoded point cloud point Chroma reconstruction value.
The method according to claim 12, wherein the chrominance reconstruction value corresponding to the chrominance channel is the chrominance residual corresponding to the inverse quantized chrominance channel and the currently decoded point cloud point. The chrominance prediction values corresponding to the chrominance channels are added together.
A point cloud attribute encoding method, comprising:

Get the point cloud to be encoded;

generating a color identifier for indicating whether the point cloud attribute of the point cloud to be encoded contains color data, and encoding the color identifier into a code stream;

When the color identifier indicates that the point cloud attribute of the to-be-coded point cloud contains color data, the offset of the quantization parameter of the chrominance channel is encoded to the code stream;

Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

Using the quantization parameter of the chrominance channel to quantize the chrominance residual corresponding to the chrominance channel;

When the color identification indicates that the point cloud attribute of the point cloud to be encoded does not contain color data, the offset of the quantization parameter of the chrominance channel is not encoded.
The method according to claim 14, wherein the offset of the quantization parameter of the chrominance channel comprises: the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel shift.
The method according to claim 15, wherein one of the first chrominance channel and the second chrominance channel is a Cb chrominance channel, and the other is a Cr chrominance channel.
The method according to claim 15, wherein the offset of the quantization parameter of the encoded chrominance channel to the code stream comprises:

If either the offset of the quantization parameter of the first chrominance channel or the offset of the quantization parameter of the second chrominance channel is not a preset value, encode the switch flag corresponding to the ON state into the code stream, and The offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are encoded into the code stream.
The method of claim 17, wherein the method further comprises:

If the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are both preset values, encode the switch flag corresponding to the off state to the code stream, and do not encode the The offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel.
The method according to any one of claims 14-18, characterized in that before using the quantization parameter of the chrominance channel to quantize the chrominance residual corresponding to the chrominance channel, the method further comprises:

The quantization parameter of the chrominance channel is limited between the minimum quantization parameter corresponding to the chrominance channel and the maximum quantization parameter corresponding to the chrominance channel.
The method according to claim 19, wherein the minimum quantization parameter corresponding to the chrominance channel and the minimum quantization parameter corresponding to the luminance channel are the same or different, and the maximum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel. The maximum quantization parameter is the same or different.
The method according to any one of claims 14-20, wherein the offset of the quantization parameter of the chrominance channel is a signed number.
The method according to claim 21, wherein the offset of the quantization parameter of the chrominance channel is binarized by using signed exponential Golomb.
The method according to any one of claims 14-22, wherein the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.
The method according to any one of claims 14-23, wherein the method further comprises:

The chrominance residual corresponding to the quantized chrominance channel is encoded into the code stream.
The method according to any one of claims 14-24, wherein the chroma residual corresponding to the chroma channel is the chroma true value corresponding to the chroma channel of the currently encoded point cloud point and the The chrominance prediction value corresponding to the chrominance channel is obtained by doing the difference.
A method for decoding point cloud attributes, comprising:

Decode the offsets of the quantization parameters corresponding to each of the multiple chrominance channels from the code stream;

For each chrominance channel in the plurality of chrominance channels, calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

For each chrominance channel, use the quantization parameter of the chrominance channel to perform inverse quantization on the chrominance residual corresponding to the chrominance channel.
27. The method of claim 26, wherein the plurality of chrominance channels comprises two chrominance channels.
The method of claim 27, wherein the two chrominance channels comprise: a Cb chrominance channel and a Cr chrominance channel.
The method according to any one of claims 26-28, wherein the decoding the offsets of the quantization parameters corresponding to each of the multiple chrominance channels from the code stream comprises:

Decode the color identification of point cloud attributes from the code stream;

If the color identifier indicates that the point cloud attribute contains color data, the offsets of the quantization parameters corresponding to each of the plurality of chrominance channels are decoded from the code stream.
The method of claim 29, wherein the method further comprises:

If the color identifier indicates that the point cloud attribute does not contain color data, it is determined that there is no offset of the quantization parameter corresponding to each of the plurality of chrominance channels in the code stream.
The method according to any one of claims 26-30, wherein the decoding the offsets of the quantization parameters corresponding to the multiple chrominance channels from the code stream comprises:

Decode the switch ID from the code stream;

If the switch flag corresponds to an on state, the offsets of the quantization parameters corresponding to each of the multiple chrominance channels are decoded from the code stream.
The method of claim 31, wherein the method further comprises:

If the switch identifier corresponds to an off state, it is determined that there is no offset of the quantization parameter corresponding to each of the plurality of chrominance channels in the code stream.
The method of claim 31, wherein the method further comprises:

If the switch identifier corresponds to an off state, it is determined that the offsets of the quantization parameters corresponding to the plurality of chrominance channels are all preset values.
The method according to any one of claims 26-33, wherein before performing inverse quantization on the chrominance residual corresponding to the chrominance channel by using the quantization parameter of the chrominance channel, the method further comprises: :

The quantization parameter of the chrominance channel is limited between the minimum quantization parameter corresponding to the chrominance channel and the maximum quantization parameter corresponding to the chrominance channel.
The method according to claim 34, wherein the minimum quantization parameter corresponding to the chrominance channel and the minimum quantization parameter corresponding to the luminance channel are the same or different, and the maximum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel. The maximum quantization parameter is the same or different.
The method according to any one of claims 26-35, wherein the offset of the quantization parameter of the chrominance channel is a signed number.
The method according to claim 36, wherein the offset of the quantization parameter of the chrominance channel is binarized by using signed exponential Golomb.
The method according to any one of claims 26-37, wherein the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.
The method according to any one of claims 26-38, wherein the inverse quantized chroma residual corresponding to the chroma channel is used to calculate the chroma residual corresponding to the chroma channel of the currently decoded point cloud point Chroma reconstruction value.
The method according to claim 39, wherein the chrominance reconstruction value corresponding to the chrominance channel is the chrominance residual corresponding to the inverse quantized chrominance channel and the currently decoded point cloud point. The chrominance prediction values corresponding to the chrominance channels are added together.
A point cloud attribute encoding method, comprising:

encoding the offsets of the quantization parameters corresponding to the multiple chrominance channels into the code stream;

For each chrominance channel in the plurality of chrominance channels, calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

For each chrominance channel, the chrominance residual corresponding to the chrominance channel is quantized by using the quantization parameter of the chrominance channel.
41. The method of claim 41, wherein the plurality of chrominance channels comprises two chrominance channels.
The method of claim 42, wherein the two chrominance channels comprise: a Cb chrominance channel and a Cr chrominance channel.
The method according to any one of claims 41-43, wherein the encoding the offsets of the quantization parameters corresponding to the multiple chrominance channels into the code stream comprises:

Generate a corresponding color mark according to whether the point cloud attribute of the point cloud to be encoded contains color data, and encode the color mark to the code stream;

If the color identifier indicates that the point cloud attribute of the point cloud to be encoded includes color data, the offsets of the quantization parameters corresponding to the multiple chrominance channels are encoded into the code stream.
The method of claim 44, wherein the method further comprises:

If the color identifier indicates that the point cloud attribute of the to-be-encoded point cloud does not contain color data, the offset of the quantization parameter corresponding to each of the plurality of chrominance channels is not encoded.
The method according to any one of claims 41-45, wherein the encoding the offsets of the quantization parameters corresponding to the multiple chrominance channels into the code stream comprises:

If any of the offsets of the quantization parameters corresponding to the multiple chroma channels is not a preset value, encode the switch flag corresponding to the on state to the code stream, and quantize the corresponding quantization parameters of the multiple chroma channels The offset of the parameter is encoded into the codestream.
The method of claim 46, wherein the method further comprises:

If the offsets of the quantization parameters corresponding to the multiple chrominance channels are all preset values, encode the switch flag corresponding to the off state to the code stream, and do not encode the offsets of the quantization parameters corresponding to the multiple chrominance channels. shift.
The method according to any one of claims 41-47, wherein before using the quantization parameter of the chrominance channel to quantize the chrominance residual corresponding to the chrominance channel, the method further comprises:

The quantization parameter of the chrominance channel is limited between the minimum quantization parameter corresponding to the chrominance channel and the maximum quantization parameter corresponding to the chrominance channel.
The method according to claim 48, wherein the minimum quantization parameter corresponding to the chrominance channel and the minimum quantization parameter corresponding to the luminance channel are the same or different, and the maximum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel. The maximum quantization parameter is the same or different.
The method according to any one of claims 41-49, wherein the offset of the quantization parameter of the chrominance channel is a signed number.
The method according to claim 50, wherein the offset of the quantization parameter of the chrominance channel is binarized by using signed exponential Golomb.
The method according to any one of claims 41-51, wherein the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.
The method according to any one of claims 41-52, wherein the method further comprises:

The chrominance residuals corresponding to each of the quantized chrominance channels are encoded into the code stream.
The method according to any one of claims 41-53, wherein the chroma residual corresponding to the chroma channel is the chroma true value corresponding to the chroma channel of the currently encoded point cloud point and the The chrominance prediction value corresponding to the chrominance channel is obtained by doing the difference.
A method for decoding point cloud attributes, comprising:

Decode the offset of the quantization parameter of the chrominance channel from the code stream, the offset of the quantization parameter of the chrominance channel is a signed number;

Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

The chrominance residual corresponding to the chrominance channel is inversely quantized by using the quantization parameter of the chrominance channel.
The method according to claim 55, wherein the offset of the quantization parameter of the chrominance channel is binarized by using signed exponential Golomb.
The method according to claim 55, wherein the offset of the quantization parameter of the chrominance channel comprises: the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel shift.
The method of claim 57, wherein one of the first chrominance channel and the second chrominance channel is a Cb chrominance channel and the other is a Cr chrominance channel.
The method according to claim 57, wherein the decoding the offset of the quantization parameter of the chrominance channel from the code stream comprises:

Decode the switch ID from the code stream;

If the switch identifier corresponds to an on state, the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are decoded from the code stream.
The method of claim 59, wherein the method further comprises:

If the switch flag corresponds to an off state, it is determined that the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel do not exist in the code stream.
The method of claim 60, wherein the method further comprises:

If the switch flag corresponds to an off state, it is determined that the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are both preset values.
The method according to any one of claims 55-61, wherein the decoding the offset of the quantization parameter of the chrominance channel from the code stream comprises:

Decode the color identification of point cloud attributes from the code stream;

If the color flag indicates that the point cloud attribute contains color data, the offset of the quantization parameter of the chrominance channel is decoded from the code stream.
The method of claim 62, wherein the method further comprises:

If the color identifier indicates that the point cloud attribute does not contain color data, it is determined that the offset of the quantization parameter of the chrominance channel does not exist in the code stream.
The method according to claim 62, wherein the color identifier is first decoded from a code stream, and if the color identifier indicates that the point cloud attribute contains color data, then the switch identifier is decoded from the code stream.
The method according to any one of claims 55-64, wherein before performing inverse quantization on the chrominance residual corresponding to the chrominance channel by using the quantization parameter of the chrominance channel, the method further comprises: :

The quantization parameter of the chrominance channel is limited between the minimum quantization parameter corresponding to the chrominance channel and the maximum quantization parameter corresponding to the chrominance channel.
The method according to claim 65, wherein the minimum quantization parameter corresponding to the chrominance channel and the minimum quantization parameter corresponding to the luminance channel are the same or different, and the maximum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel. The maximum quantization parameter is the same or different.
The method according to any one of claims 55-66, wherein the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.
The method according to any one of claims 55-67, wherein the inverse quantized chroma residual corresponding to the chroma channel is used to calculate the chroma residual corresponding to the chroma channel of the currently decoded point cloud point Chroma reconstruction value.
The method according to claim 68, wherein the chrominance reconstruction value corresponding to the chrominance channel is the chrominance residual corresponding to the inverse quantized chrominance channel and the currently decoded point cloud point. The chrominance prediction values corresponding to the chrominance channels are added together.
A point cloud attribute encoding method, comprising:

encoding the offset of the quantization parameter of the chrominance channel into the code stream, the offset of the quantization parameter of the chrominance channel being a signed number;

Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

The chrominance residual corresponding to the chrominance channel is quantized by using the quantization parameter of the chrominance channel.
The method according to claim 70, wherein the offset of the quantization parameter of the chrominance channel is binarized by using signed exponential Golomb.
The method according to claim 70, wherein the offset of the quantization parameter of the chrominance channel comprises: the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel shift.
The method of claim 72, wherein one of the first chrominance channel and the second chrominance channel is a Cb chrominance channel and the other is a Cr chrominance channel.
The method according to claim 72, wherein the encoding the offset of the quantization parameter of the chrominance channel into the code stream comprises:

If either the offset of the quantization parameter of the first chrominance channel or the offset of the quantization parameter of the second chrominance channel is not a preset value, encode the switch flag corresponding to the ON state into the code stream, and The offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are encoded into the code stream.
The method of claim 74, wherein the method further comprises:

If the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are both preset values, encode the switch flag corresponding to the off state to the code stream, and do not encode the The offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel.
The method according to any one of claims 70-75, wherein the encoding the offset of the quantization parameter of the chrominance channel into the code stream comprises:

Generate a corresponding color mark according to whether the point cloud attribute of the point cloud to be encoded contains color data, and encode the color mark to the code stream;

If the color identifier indicates that the point cloud attribute of the point cloud to be encoded contains color data, the offset of the quantization parameter of the chrominance channel is encoded into the code stream.
The method of claim 76, wherein the method further comprises:

If the color identifier indicates that the point cloud attribute of the point cloud to be encoded does not contain color data, the offset of the quantization parameter of the chrominance channel is not encoded.
The method according to claim 76, wherein the color identifier is encoded into a code stream first, and if the color identifier indicates that the point cloud attribute contains color data, then the switch identifier is encoded into the code stream.
The method according to any one of claims 70-78, wherein before using the quantization parameter of the chrominance channel to quantize the chrominance residual corresponding to the chrominance channel, the method further comprises:

The quantization parameter of the chrominance channel is limited between the minimum quantization parameter corresponding to the chrominance channel and the maximum quantization parameter corresponding to the chrominance channel.
The method according to claim 79, wherein the minimum quantization parameter corresponding to the chrominance channel and the minimum quantization parameter corresponding to the luminance channel are the same or different, and the maximum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel. The maximum quantization parameter is the same or different.
The method according to any one of claims 70-80, wherein the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.
The method according to any one of claims 70-81, wherein the method further comprises:

The chrominance residual corresponding to the quantized chrominance channel is encoded into the code stream.
The method according to any one of claims 70-82, wherein the chroma residual corresponding to the chroma channel is the true chroma value corresponding to the chroma channel of the currently encoded point cloud point and the The chrominance prediction value corresponding to the chrominance channel is obtained by doing the difference.
A point cloud attribute decoding device, comprising: a processor and a memory storing a computer program, wherein the processor implements the following steps when executing the computer program:

Decode the color identification of point cloud attributes from the code stream;

When the color identifier indicates that the point cloud attribute contains color data, decoding the offset of the quantization parameter of the chrominance channel from the code stream;

Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

Perform inverse quantization on the chrominance residual corresponding to the chrominance channel by using the quantization parameter of the chrominance channel;

When the color identifier indicates that the point cloud attribute does not contain color data, it is determined that there is no offset of the quantization parameter of the chrominance channel in the code stream.
The apparatus according to claim 84, wherein the offset of the quantization parameter of the chrominance channel comprises: the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel shift.
The apparatus of claim 85, wherein one of the first chrominance channel and the second chrominance channel is a Cb chrominance channel and the other is a Cr chrominance channel.
The apparatus according to claim 85, wherein when the processor decodes the offset of the quantization parameter of the chrominance channel from the code stream:

Decode the switch ID from the code stream;

If the switch identifier corresponds to an on state, the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are decoded from the code stream.
The apparatus of claim 87, wherein the processor is further configured to:

If the switch flag corresponds to an off state, it is determined that the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel do not exist in the code stream.
The apparatus of claim 87, wherein the processor is further configured to:

If the switch flag corresponds to an off state, it is determined that the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are both preset values.
The apparatus according to any one of claims 84-89, wherein the processor is further configured to:

Before using the quantization parameter of the chrominance channel to perform inverse quantization on the chrominance residual corresponding to the chrominance channel, the quantization parameter of the chrominance channel is limited to the minimum quantization parameter corresponding to the chrominance channel and the between the maximum quantization parameters corresponding to the chrominance channels.
The method according to claim 90, wherein the minimum quantization parameter corresponding to the chrominance channel and the minimum quantization parameter corresponding to the luminance channel are the same or different, and the maximum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel. The maximum quantization parameter is the same or different.
The apparatus according to any one of claims 84-91, wherein the offset of the quantization parameter of the chrominance channel is a signed number.
The method according to claim 92, wherein the offset of the quantization parameter of the chrominance channel is binarized by using signed exponential Golomb.
The apparatus according to any one of claims 84-93, wherein the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.
The apparatus according to any one of claims 84 to 94, wherein the inverse quantized chroma residual corresponding to the chroma channel is used to calculate the chroma residual corresponding to the chroma channel of the currently decoded point cloud point Chroma reconstruction value.
The apparatus according to claim 95, wherein the chrominance reconstruction value corresponding to the chrominance channel is the inverse quantized chrominance residual corresponding to the chrominance channel and the value of the currently decoded point cloud point. The chrominance prediction values corresponding to the chrominance channels are added together.
A point cloud attribute encoding device, comprising: a processor and a memory storing a computer program, wherein the processor implements the following steps when executing the computer program:

Get the point cloud to be encoded;

generating a color identifier for indicating whether the point cloud attribute of the point cloud to be encoded contains color data, and encoding the color identifier into a code stream;

When the color identifier indicates that the point cloud attribute of the to-be-coded point cloud contains color data, the offset of the quantization parameter of the chrominance channel is encoded to the code stream;

Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

Using the quantization parameter of the chrominance channel to quantize the chrominance residual corresponding to the chrominance channel;

When the color identification indicates that the point cloud attribute of the point cloud to be encoded does not contain color data, the offset of the quantization parameter of the chrominance channel is not encoded.
The apparatus according to claim 97, wherein the offset of the quantization parameter of the chrominance channel comprises: the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel shift.
The apparatus of claim 98, wherein one of the first chrominance channel and the second chrominance channel is a Cb chrominance channel and the other is a Cr chrominance channel.
The apparatus according to claim 98, wherein when encoding the offset of the quantization parameter of the chrominance channel to the code stream, the processor is configured to:

If either the offset of the quantization parameter of the first chrominance channel or the offset of the quantization parameter of the second chrominance channel is not a preset value, encode the switch flag corresponding to the ON state into the code stream, and The offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are encoded into the code stream.
The apparatus of claim 100, wherein the processor is further configured to:

If the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are both preset values, encode the switch flag corresponding to the off state to the code stream, and do not encode the The offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel.
The apparatus according to any one of claims 97-101, wherein the processor is further configured to:

Before using the quantization parameter of the chrominance channel to quantize the chrominance residual corresponding to the chrominance channel, limit the quantization parameter of the chrominance channel to the minimum quantization parameter corresponding to the chrominance channel and the chrominance channel. between the maximum quantization parameters corresponding to the chroma channels.
The method according to claim 102, wherein the minimum quantization parameter corresponding to the chrominance channel and the minimum quantization parameter corresponding to the luminance channel are the same or different, and the maximum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel. The maximum quantization parameter is the same or different.
The apparatus according to any one of claims 97-103, wherein the offset of the quantization parameter of the chrominance channel is a signed number.
The method according to claim 104, wherein the offset of the quantization parameter of the chrominance channel is binarized by using signed exponential Golomb.
The apparatus according to any one of claims 97-105, wherein the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.
The apparatus according to any one of claims 97-106, wherein the processor is further configured to:

The chrominance residual corresponding to the quantized chrominance channel is encoded into the code stream.
The apparatus according to any one of claims 97-107, wherein the chroma residual corresponding to the chroma channel is the true chroma value corresponding to the chroma channel of the currently encoded point cloud point and the The chrominance prediction value corresponding to the chrominance channel is obtained by doing the difference.
A point cloud attribute decoding device, comprising: a processor and a memory storing a computer program, wherein the processor implements the following steps when executing the computer program:

Decode the offsets of the quantization parameters corresponding to each of the multiple chrominance channels from the code stream;

For each chrominance channel in the plurality of chrominance channels, calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

For each chrominance channel, use the quantization parameter of the chrominance channel to perform inverse quantization on the chrominance residual corresponding to the chrominance channel.
109. The apparatus of claim 109, wherein the plurality of chrominance channels includes two chrominance channels.
The apparatus of claim 110, wherein the two chrominance channels comprise: a Cb chrominance channel and a Cr chrominance channel.
The apparatus according to any one of claims 109-111, wherein when the processor decodes the offsets of the quantization parameters corresponding to the multiple chrominance channels from the code stream, it is used for:

Decode the color identification of point cloud attributes from the code stream;

If the color identifier indicates that the point cloud attribute contains color data, the offsets of the quantization parameters corresponding to each of the plurality of chrominance channels are decoded from the code stream.
The apparatus of claim 112, wherein the processor is further configured to:

If the color identifier indicates that the point cloud attribute does not contain color data, it is determined that there is no offset of the quantization parameter corresponding to each of the plurality of chrominance channels in the code stream.
The apparatus according to any one of claims 109-113, wherein when the processor decodes the offsets of the quantization parameters corresponding to the multiple chrominance channels from the code stream, it is used for:

Decode the switch ID from the code stream;

If the switch flag corresponds to an on state, the offsets of the quantization parameters corresponding to each of the multiple chrominance channels are decoded from the code stream.
The apparatus of claim 114, wherein the processor is further configured to:

If the switch identifier corresponds to an off state, it is determined that there is no offset of the quantization parameter corresponding to each of the plurality of chrominance channels in the code stream.
The apparatus of claim 114, wherein the processor is further configured to:

If the switch identifier corresponds to an off state, it is determined that the offsets of the quantization parameters corresponding to the plurality of chrominance channels are all preset values.
The apparatus according to any one of claims 109-116, wherein the processor is further configured to:

Before using the quantization parameter of the chrominance channel to perform inverse quantization on the chrominance residual corresponding to the chrominance channel, the quantization parameter of the chrominance channel is limited to the minimum quantization parameter corresponding to the chrominance channel and the between the maximum quantization parameters corresponding to the chrominance channels.
The method according to claim 117, wherein the minimum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel, and the maximum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel. The maximum quantization parameter is the same or different.
The apparatus according to any one of claims 109-117, wherein the offset of the quantization parameter of the chrominance channel is a signed number.
The method according to claim 119, wherein the offset of the quantization parameter of the chrominance channel is binarized by using signed exponential Golomb.
The apparatus according to any one of claims 109-120, wherein the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.
The apparatus according to any one of claims 109-120, wherein the inverse quantized chroma residual corresponding to the chroma channel is used to calculate the chroma residual corresponding to the chroma channel of the currently decoded point cloud point Chroma reconstruction value.
The apparatus according to claim 122, wherein the chroma reconstruction value corresponding to the chroma channel is the inverse quantized chroma residual corresponding to the chroma channel and the value of the currently decoded point cloud point. The chrominance prediction values corresponding to the chrominance channels are added together.
A point cloud attribute encoding device, comprising: a processor and a memory storing a computer program, wherein the processor implements the following steps when executing the computer program:

encoding the offsets of the quantization parameters corresponding to the multiple chrominance channels into the code stream;

For each chrominance channel in the plurality of chrominance channels, calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

For each chrominance channel, the chrominance residual corresponding to the chrominance channel is quantized by using the quantization parameter of the chrominance channel.
124. The apparatus of claim 124, wherein the plurality of chrominance channels comprises two chrominance channels.
The apparatus of claim 125, wherein the two chrominance channels comprise: a Cb chrominance channel and a Cr chrominance channel.
The apparatus according to any one of claims 124 to 126, wherein when the processor encodes the offsets of the quantization parameters corresponding to the multiple chrominance channels into the code stream:

Generate a corresponding color mark according to whether the point cloud attribute of the point cloud to be encoded contains color data, and encode the color mark to the code stream;

If the color identifier indicates that the point cloud attribute of the point cloud to be encoded includes color data, the offsets of the quantization parameters corresponding to the multiple chrominance channels are encoded into the code stream.
The apparatus of claim 127, wherein the processor is further configured to:

If the color identifier indicates that the point cloud attribute of the to-be-encoded point cloud does not contain color data, the offset of the quantization parameter corresponding to each of the plurality of chrominance channels is not encoded.
The apparatus according to any one of claims 124-128, wherein when the processor encodes the offsets of the quantization parameters corresponding to the multiple chrominance channels into the code stream, the processor is used for:

If any of the offsets of the quantization parameters corresponding to the multiple chroma channels is not a preset value, encode the switch flag corresponding to the on state to the code stream, and quantize the corresponding quantization parameters of the multiple chroma channels The offset of the parameter is encoded into the codestream.
The apparatus of claim 129, wherein the processor is further configured to:

If the offsets of the quantization parameters corresponding to the multiple chrominance channels are all preset values, encode the switch flag corresponding to the off state to the code stream, and do not encode the offsets of the quantization parameters corresponding to the multiple chrominance channels. shift.
The apparatus according to any one of claims 124-130, wherein the processor is further configured to:

Before using the quantization parameter of the chrominance channel to quantize the chrominance residual corresponding to the chrominance channel, limit the quantization parameter of the chrominance channel to the minimum quantization parameter corresponding to the chrominance channel and the chrominance channel. between the maximum quantization parameters corresponding to the chroma channels.
The method according to claim 131, wherein the minimum quantization parameter corresponding to the chrominance channel and the minimum quantization parameter corresponding to the luminance channel are the same or different, and the maximum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel. The maximum quantization parameter is the same or different.
The apparatus according to any one of claims 124-132, wherein the offset of the quantization parameter of the chrominance channel is a signed number.
The method according to claim 133, wherein the offset of the quantization parameter of the chrominance channel is binarized by using signed exponential Golomb.
The apparatus according to any one of claims 124-134, wherein the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.
The apparatus according to any one of claims 124-135, wherein the processor is further configured to:

The chrominance residuals corresponding to each of the quantized chrominance channels are encoded into the code stream.
The apparatus according to any one of claims 124-136, wherein the chroma residual corresponding to the chroma channel is the true chroma value corresponding to the chroma channel of the currently encoded point cloud point and the The chrominance prediction value corresponding to the chrominance channel is obtained by doing the difference.
A point cloud attribute decoding device, comprising: a processor and a memory storing a computer program, wherein the processor implements the following steps when executing the computer program:

Decode the offset of the quantization parameter of the chrominance channel from the code stream, the offset of the quantization parameter of the chrominance channel is a signed number;

Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

The chrominance residual corresponding to the chrominance channel is inversely quantized by using the quantization parameter of the chrominance channel.
The method according to claim 138, wherein the offset of the quantization parameter of the chrominance channel is binarized by using signed exponential Golomb.
The apparatus according to claim 138, wherein the offset of the quantization parameter of the chrominance channel comprises: the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel shift.
The apparatus of claim 140, wherein one of the first chrominance channel and the second chrominance channel is a Cb chrominance channel, and the other is a Cr chrominance channel.
The apparatus according to claim 140, wherein when the processor decodes the offset of the quantization parameter of the chrominance channel from the code stream:

Decode the switch ID from the code stream;

If the switch identifier corresponds to an on state, the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are decoded from the code stream.
The apparatus of claim 142, wherein the processor is further configured to:

If the switch flag corresponds to an off state, it is determined that the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel do not exist in the code stream.
The apparatus of claim 142, wherein the processor is further configured to:

If the switch flag corresponds to an off state, it is determined that the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are both preset values.
The apparatus according to any one of claims 138-144, wherein when the processor decodes the offset of the quantization parameter of the chrominance channel from the code stream:

Decode the color identification of point cloud attributes from the code stream;

If the color flag indicates that the point cloud attribute contains color data, the offset of the quantization parameter of the chrominance channel is decoded from the code stream.
The apparatus of claim 145, wherein the processor is further configured to:

If the color identifier indicates that the point cloud attribute does not contain color data, it is determined that the offset of the quantization parameter of the chrominance channel does not exist in the code stream.
The apparatus according to claim 145, wherein the color identifier is first decoded from a code stream, and if the color identifier indicates that the point cloud attribute contains color data, then the switch identifier is decoded from the code stream.
The apparatus according to any one of claims 138-147, wherein the processor is further configured to:

Before using the quantization parameter of the chrominance channel to perform inverse quantization on the chrominance residual corresponding to the chrominance channel, the quantization parameter of the chrominance channel is limited to the minimum quantization parameter corresponding to the chrominance channel and the between the maximum quantization parameters corresponding to the chrominance channels.
The method according to claim 148, wherein the minimum quantization parameter corresponding to the chrominance channel and the minimum quantization parameter corresponding to the luminance channel are the same or different, and the maximum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel. The maximum quantization parameter is the same or different.
The apparatus according to any one of claims 138-149, wherein the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.
The apparatus according to any one of claims 138 to 150, wherein the inverse quantized chroma residual corresponding to the chroma channel is used to calculate the chroma residual corresponding to the chroma channel of the currently decoded point cloud point Chroma reconstruction value.
The apparatus according to claim 151, wherein the chroma reconstruction value corresponding to the chroma channel is the inverse quantized chroma residual corresponding to the chroma channel and the value of the currently decoded point cloud point. The chrominance prediction values corresponding to the chrominance channels are added together.
A point cloud attribute encoding device, comprising: a processor and a memory storing a computer program, wherein the processor implements the following steps when executing the computer program:

encoding the offset of the quantization parameter of the chrominance channel into the code stream, the offset of the quantization parameter of the chrominance channel being a signed number;

Calculate the quantization parameter of the chrominance channel according to the offset of the quantization parameter of the chrominance channel;

The chrominance residual corresponding to the chrominance channel is quantized by using the quantization parameter of the chrominance channel.
The method according to claim 153, wherein the offset of the quantization parameter of the chrominance channel is binarized by using signed exponential Golomb.
The apparatus according to claim 153, wherein the offset of the quantization parameter of the chrominance channel comprises: the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel shift.
The apparatus of claim 155, wherein one of the first chrominance channel and the second chrominance channel is a Cb chrominance channel and the other is a Cr chrominance channel.
The apparatus according to claim 155, wherein when the processor encodes the offset of the quantization parameter of the chrominance channel into the code stream:

If either the offset of the quantization parameter of the first chrominance channel or the offset of the quantization parameter of the second chrominance channel is not a preset value, encode the switch flag corresponding to the ON state into the code stream, and The offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are encoded into the code stream.
The apparatus of claim 157, wherein the processor is further configured to:

If the offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel are both preset values, encode the switch flag corresponding to the off state to the code stream, and do not encode the The offset of the quantization parameter of the first chrominance channel and the offset of the quantization parameter of the second chrominance channel.
The apparatus according to any one of claims 153-158, wherein when the processor encodes the offset of the quantization parameter of the chrominance channel into the code stream:

Generate a corresponding color mark according to whether the point cloud attribute of the point cloud to be encoded contains color data, and encode the color mark to the code stream;

If the color identifier indicates that the point cloud attribute of the point cloud to be encoded contains color data, the offset of the quantization parameter of the chrominance channel is encoded into the code stream.
The apparatus of claim 159, wherein the processor is further configured to:

If the color identifier indicates that the point cloud attribute of the point cloud to be encoded does not contain color data, the offset of the quantization parameter of the chrominance channel is not encoded.
The apparatus according to claim 159, wherein the color flag is encoded into a code stream first, and if the color flag indicates that the point cloud attribute contains color data, then the switch flag is encoded into the code stream.
The apparatus according to any one of claims 153-161, wherein the processor is further configured to:

Before using the quantization parameter of the chrominance channel to quantize the chrominance residual corresponding to the chrominance channel,

The quantization parameter of the chrominance channel is limited between the minimum quantization parameter corresponding to the chrominance channel and the maximum quantization parameter corresponding to the chrominance channel.
The method according to claim 162, wherein the minimum quantization parameter corresponding to the chrominance channel and the minimum quantization parameter corresponding to the luminance channel are the same or different, and the maximum quantization parameter corresponding to the chrominance channel is the same as or different from the minimum quantization parameter corresponding to the luminance channel. The maximum quantization parameter is the same or different.
The apparatus according to any one of claims 153-163, wherein the quantization parameter of the chrominance channel is obtained by adding the offset of the quantization parameter of the chrominance channel and the quantization parameter of the luminance channel.
The apparatus according to any one of claims 153-164, wherein the processor is further configured to:

The chrominance residual corresponding to the quantized chrominance channel is encoded into the code stream.
The apparatus according to any one of claims 153-165, wherein the chroma residual corresponding to the chroma channel is the true chroma value corresponding to the chroma channel of the currently encoded point cloud point and the The chrominance prediction value corresponding to the chrominance channel is obtained by doing the difference.
A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the point cloud attribute decoding according to any one of claims 1-13 is implemented method.
A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, implements the point cloud attribute encoding according to any one of claims 14-25 method.
A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the point cloud attribute decoding according to any one of claims 26-40 is implemented method.
A computer-readable storage medium, characterized in that, the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the point cloud attribute encoding according to any one of claims 41-54 is implemented method.
A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the point cloud attribute decoding according to any one of claims 55-69 is implemented method.
A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, implements the point cloud attribute encoding according to any one of claims 70-83 method.