WO2024007144A1 - Procédé de codage, procédé de décodage, flux de code, codeurs, décodeurs et support de stockage - Google Patents

Procédé de codage, procédé de décodage, flux de code, codeurs, décodeurs et support de stockage Download PDF

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WO2024007144A1
WO2024007144A1 PCT/CN2022/103817 CN2022103817W WO2024007144A1 WO 2024007144 A1 WO2024007144 A1 WO 2024007144A1 CN 2022103817 W CN2022103817 W CN 2022103817W WO 2024007144 A1 WO2024007144 A1 WO 2024007144A1
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value
absolute value
quantized residual
residual
attribute
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PCT/CN2022/103817
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Chinese (zh)
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魏红莲
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Oppo广东移动通信有限公司
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/124—Quantisation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/60—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using transform coding
    • H04N19/61—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using transform coding in combination with predictive coding

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  • the embodiments of the present application relate to the field of point cloud compression technology, and in particular, to a coding and decoding method, a code stream, an encoder, a decoder, and a storage medium.
  • the geometric information and attribute information of the point cloud are encoded separately. After the geometric encoding is completed, the geometric information is reconstructed, and the encoding of attribute information will depend on the reconstructed geometric information.
  • attribute information encoding is mainly aimed at encoding color information, converting it into a YUV color space that is more in line with human visual characteristics, and then performing attribute encoding on the preprocessed attribute information, and finally generating a binary attribute code stream.
  • the obtained attribute residual value can be either positive or negative.
  • the sign identification information is encoded together with the attribute residual value; and the encoding of the sign identification information also requires the use of codewords, thus reducing the encoding and decoding efficiency.
  • Embodiments of the present application provide a coding and decoding method, a code stream, an encoder, a decoder, and a storage medium, which can reduce the number of codewords used when encoding attribute information, thereby improving coding and decoding efficiency.
  • embodiments of the present application provide a decoding method, which is applied to a decoder.
  • the method includes:
  • the attribute reconstruction value of the current point is determined.
  • inventions of the present application provide an encoding method, which is applied to an encoder.
  • the method includes:
  • embodiments of the present application provide a code stream.
  • the code stream is generated by bit encoding based on the information to be encoded.
  • the information to be encoded at least includes: the absolute value of the quantized residual of the current point, or the absolute value of the quantized residual of the current point.
  • the absolute value of the quantized residual and the corresponding symbol identification information are included in the code stream.
  • embodiments of the present application provide an encoder, which includes a first determination unit and a coding unit; wherein,
  • a first determination unit configured to determine the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point; and when the absolute value of the initial quantized residual satisfies the first preset condition, according to the sign and the initial Quantize the parity characteristics of the absolute value of the residual and determine the absolute value of the quantized residual at the current point;
  • the encoding unit is configured to encode the absolute value of the quantization residual and write the resulting encoded bits into the code stream.
  • embodiments of the present application provide an encoder, which includes a first memory and a first processor; wherein,
  • a first memory for storing a computer program capable of running on the first processor
  • the first processor is configured to perform the method described in the first aspect when running the computer program.
  • embodiments of the present application provide a decoder, which includes a decoding unit and a second determination unit; wherein,
  • the decoding unit is configured to parse the code stream and determine the absolute value of the quantized residual at the current point;
  • the second determination unit is configured to determine the sign of the quantized residual at the current point according to the parity characteristics of the absolute value of the quantized residual when the absolute value of the quantized residual satisfies the first preset condition; and based on the absolute value of the quantized residual and symbols, determine the attribute reconstruction value of the current point.
  • embodiments of the present application provide a decoder, which includes a second memory and a second processor; wherein,
  • a second memory for storing a computer program capable of running on the second processor
  • the second processor is configured to perform the method described in the second aspect when running the computer program.
  • embodiments of the present application provide a computer-readable storage medium that stores a computer program.
  • the computer program When the computer program is executed, the method as described in the first aspect, or the second aspect is implemented. methods described in this regard.
  • Embodiments of the present application provide a coding and decoding method, a code stream, an encoder, a decoder, and a storage medium.
  • the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point are determined;
  • the absolute value of the quantized residual at the current point is determined based on the sign and the parity characteristics of the initial quantized residual absolute value;
  • the absolute value of the quantized residual is encoded, and all The resulting coded bits are written into the code stream.
  • the code stream is parsed to determine the absolute value of the quantized residual at the current point; when the absolute value of the quantized residual meets the first preset condition, the quantized residual at the current point is determined based on the parity characteristics of the absolute value of the quantized residual. The sign of the difference; determine the attribute reconstruction value of the current point based on the absolute value and sign of the quantized residual.
  • the parity characteristics based on the absolute value of the quantized residual can hide some symbols of the values to be encoded, that is, there is no need to encode these symbols, so as to reduce the codewords used when encoding attribute information; while on the decoding side, The corresponding symbol can be directly determined based on the parity and even characteristics of the absolute value of the quantized residual obtained by decoding; thus, the use of codewords can be reduced, the encoding and decoding efficiency of point cloud attributes can be improved, and the encoding and decoding performance of point cloud attributes can be improved.
  • Figure 1A is a schematic diagram of a three-dimensional point cloud image provided by an embodiment of the present application.
  • Figure 1B is a partially enlarged schematic diagram of a three-dimensional point cloud image provided by an embodiment of the present application.
  • Figure 2A is a schematic diagram of point cloud images at different viewing angles provided by an embodiment of the present application.
  • Figure 2B is a schematic diagram of the data storage format corresponding to Figure 2A provided by an embodiment of the present application;
  • Figure 3 is a schematic diagram of a point cloud encoding and decoding network architecture provided by an embodiment of the present application
  • Figure 4 is a schematic structural diagram of a point cloud encoder provided by an embodiment of the present application.
  • Figure 5 is a schematic structural diagram of a point cloud decoder provided by an embodiment of the present application.
  • Figure 6 is a schematic flow chart of a decoding method provided by an embodiment of the present application.
  • Figure 7 is a detailed flow chart of a decoding method provided by an embodiment of the present application.
  • Figure 8 is a schematic flow chart of an encoding method provided by an embodiment of the present application.
  • Figure 9 is a detailed flow chart of an encoding method provided by an embodiment of the present application.
  • Figure 10 is a schematic structural diagram of an encoder provided by an embodiment of the present application.
  • Figure 11 is a schematic diagram of the specific hardware structure of an encoder provided by an embodiment of the present application.
  • Figure 12 is a schematic structural diagram of a decoder provided by an embodiment of the present application.
  • Figure 13 is a schematic diagram of the specific hardware structure of a decoder provided by an embodiment of the present application.
  • Figure 14 is a schematic structural diagram of a coding and decoding system provided by an embodiment of the present application.
  • first ⁇ second ⁇ third involved in the embodiments of this application are only used to distinguish similar objects and do not represent a specific ordering of objects. It is understandable that “first ⁇ second ⁇ The third "specific order or sequence may be interchanged where permitted, so that the embodiments of the application described herein can be implemented in an order other than that illustrated or described herein.
  • Point Cloud is a three-dimensional representation of the surface of an object.
  • collection equipment such as photoelectric radar, lidar, laser scanner, and multi-view camera, the point cloud (data) of the surface of the object can be collected.
  • Point cloud is a set of discrete points randomly distributed in space that expresses the spatial structure and surface properties of a three-dimensional object or scene.
  • Figure 1A shows a three-dimensional point cloud image
  • Figure 1B shows a partial enlargement of the three-dimensional point cloud image. It can be seen that the point cloud surface is composed of densely distributed points.
  • Two-dimensional images have information expressed in each pixel and are distributed regularly, so there is no need to record additional position information; however, the distribution of points in the point cloud in the three-dimensional space is random and irregular, so each point needs to be recorded Only the position of the point in space can completely express a point cloud.
  • each position in the collection process has corresponding attribute information, usually RGB color values, and the color values reflect the color of the object; for point clouds, the attribute information corresponding to each point is in addition to color information. , and the more common one is the reflectance value, which reflects the surface material of the object. Therefore, points in the point cloud can include point location information and point attribute information.
  • the position information of the point may be the three-dimensional coordinate information (x, y, z) of the point.
  • the position information of a point can also be called the geometric information of the point.
  • the attribute information of a point may include color information (three-dimensional color information) and/or reflectance (one-dimensional reflectance information r), and so on.
  • color information can be information on any color space.
  • the color information may be RGB information. Among them, R represents red (Red, R), G represents green (Green, G), and B represents blue (Blue, B).
  • the color information may be brightness and chrominance (YCbCr, YUV) information. Among them, Y represents brightness (Luma), Cb(U) represents blue color difference, and Cr(V) represents red color difference.
  • the points in the point cloud can include the three-dimensional coordinate information of the point and the reflectivity value of the point.
  • the points in the point cloud may include the three-dimensional coordinate information of the point and the three-dimensional color information of the point.
  • a point cloud is obtained by combining the principles of laser measurement and photogrammetry. The points in the point cloud may include the three-dimensional coordinate information of the point, the reflectivity value of the point, and the three-dimensional color information of the point.
  • Figure 2A and Figure 2B show a point cloud image and its corresponding data storage format.
  • Figure 2A provides six viewing angles of the point cloud image.
  • Figure 2B is composed of the file header information part and the data part.
  • the header information includes the data format, data representation type, total number of point cloud points, and the content represented by the point cloud. .
  • the point cloud is in ".ply" format and is represented by ASCII code.
  • the total number of points is 207242.
  • Each point has three-dimensional coordinate information (x, y, z) and three-dimensional color information (r, g, b).
  • Point clouds can be divided into:
  • Static point cloud that is, the object is stationary and the device that obtains the point cloud is also stationary;
  • Dynamic point cloud The object is moving, but the device that obtains the point cloud is stationary;
  • Dynamically acquire point clouds The device that acquires point clouds is in motion.
  • point clouds are divided into two categories according to their uses:
  • Category 1 Machine perception point cloud, which can be used in scenarios such as autonomous navigation systems, real-time inspection systems, geographic information systems, visual sorting robots, and rescue and disaster relief robots;
  • Category 2 Human eye perception point cloud, which can be used in point cloud application scenarios such as digital cultural heritage, free-viewpoint broadcasting, three-dimensional immersive communication, and three-dimensional immersive interaction.
  • Point clouds can flexibly and conveniently express the spatial structure and surface properties of three-dimensional objects or scenes, and because point clouds are obtained by directly sampling real objects, they can provide a strong sense of reality while ensuring accuracy, so they are widely used and their scope Including virtual reality games, computer-aided design, geographic information systems, automatic navigation systems, digital cultural heritage, free-viewpoint broadcasting, three-dimensional immersive telepresence, three-dimensional reconstruction of biological tissues and organs, etc.
  • Point cloud collection mainly has the following methods: computer generation, 3D laser scanning, 3D photogrammetry, etc.
  • Computers can generate point clouds of virtual three-dimensional objects and scenes; 3D laser scanning can obtain point clouds of static real-world three-dimensional objects or scenes, and can obtain millions of point clouds per second; 3D photogrammetry can obtain dynamic real-world three-dimensional objects or scenes Point clouds can obtain tens of millions of point clouds per second.
  • the number of points in each frame of the point cloud is 700,000, and each point has coordinate information xyz (float) and color information RGB (uchar)
  • the data volume of 1280 ⁇ 720 2D video at 24fps for 10s is about 1280 ⁇ 720 ⁇ 12bit ⁇ 24fps ⁇ 10s ⁇ 0.33GB
  • point cloud compression has become a key issue to promote the development of the point cloud industry.
  • the point cloud is a collection of massive points, storing the point cloud will not only consume a lot of memory, but is also not conducive to transmission. There is not such a large bandwidth to support the direct transmission of the point cloud at the network layer without compression. Therefore, , the point cloud needs to be compressed.
  • the point cloud coding framework that can compress point clouds can be the Geometry-based Point Cloud Compression (G-PCC) codec framework provided by the Moving Picture Experts Group (MPEG) Or the Video-based Point Cloud Compression (V-PCC) codec framework, or the AVS-PCC codec framework provided by AVS.
  • G-PCC Geometry-based Point Cloud Compression
  • MPEG Moving Picture Experts Group
  • V-PCC Video-based Point Cloud Compression
  • AVS-PCC codec framework provided by AVS.
  • the G-PCC encoding and decoding framework can be used to compress the first type of static point cloud and the third type of dynamic point cloud
  • the V-PCC encoding and decoding framework can be used to compress the second type of dynamic point cloud.
  • the G-PCC encoding and decoding framework is also called point cloud codec TMC13
  • the V-PCC encoding and decoding framework is also called point cloud codec TMC2.
  • FIG. 3 is a schematic diagram of the network architecture of a point cloud encoding and decoding system provided by an embodiment of the present application.
  • the network architecture includes one or more electronic devices 13 to 1N and a communication network 01 , wherein the electronic devices 13 to 1N can perform video interaction through the communication network 01 .
  • electronic devices may be various types of devices with point cloud encoding and decoding functions.
  • the electronic devices may include mobile phones, tablet computers, personal computers, personal digital assistants, navigators, digital phones, and video phones.
  • televisions, sensing equipment, servers, etc. are not limited by the embodiments of this application.
  • the decoder or encoder in the embodiment of the present application can be the above-mentioned electronic device.
  • the electronic device in the embodiment of the present application has a point cloud encoding and decoding function, and generally includes a point cloud encoder (ie, encoder) and a point cloud decoder (ie, decoder).
  • a point cloud encoder ie, encoder
  • a point cloud decoder ie, decoder
  • the following uses the AVS-PCC encoding and decoding framework as an example to illustrate the point cloud compression technology.
  • point cloud compression generally adopts the method of compressing point cloud geometric information and attribute information separately.
  • the point cloud geometric information is first encoded in the geometry encoder, and then the reconstructed geometric information is input into the attribute encoder as additional information.
  • the point cloud geometric information is first decoded in the geometry decoder, and then the decoded geometric information is input into the attribute decoder as additional information to assist in the compression of point cloud attributes.
  • the entire codec consists of pre-processing/post-processing, geometry encoding/decoding, and attribute encoding/decoding.
  • the embodiment of the present application provides a point cloud encoder.
  • Figure 4 shows the framework of the point cloud compression reference platform PCRM provided by AVS.
  • the point cloud encoder 11 includes a geometric encoder: a coordinate translation unit 111 and a coordinate quantization unit. 112. Octree construction unit 113, geometric entropy encoder 114, geometric reconstruction unit 115. Attribute encoder: attribute recoloring unit 116, color space transform unit 117, first attribute prediction unit 118, quantization unit 119 and attribute entropy encoder 1110.
  • the original geometric information is first preprocessed, the geometric origin is normalized to the minimum position in the point cloud space through the coordinate translation unit 111, and the geometric information is transferred from the float to the point cloud space through the coordinate quantization unit 112.
  • the points are converted into shapes to facilitate subsequent regularization processing; then the regularized geometric information is geometrically encoded, and the octree structure is used in the octree construction unit 113 to recursively divide the point cloud space, dividing the current point each time into eight sub-blocks of the same size, and determine the occupied codeword status of each sub-block.
  • the sub-block does not contain points, it is recorded as empty, otherwise it is recorded as non-empty.
  • the occupancy of all blocks is recorded at the last level of recursive division.
  • the codeword information is geometrically encoded; on the one hand, the geometric information expressed through the octree structure is input to the geometric entropy encoder 114 to form a geometric code stream; on the other hand, the geometric reconstruction process is performed in the geometric reconstruction unit 115. The reconstructed geometry The information is input to the attribute encoder as additional information.
  • the original attribute information is first preprocessed. Since the geometric information changes after the geometric encoding, the attribute value is reassigned to each point after the geometric encoding through the attribute recoloring unit 116 to realize the attribute Repaint.
  • the attribute information being processed is color information
  • the original color information needs to be transformed into a color space through the color space transformation unit 117 to convert it into a YUV color space that is more in line with the visual characteristics of the human eye; and then predicted through the first attribute Unit 118 performs attribute encoding on the preprocessed attribute information.
  • the point cloud needs to be reordered.
  • the reordering method is Morton code, so the traversal order of attribute encoding is Morton order.
  • the attribute prediction method in PCRM is a single point prediction based on Morton order, that is, going back one point from the current point to be encoded (current point) according to Morton order, and the node found is the prediction reference point of the current point to be encoded, and then The attribute reconstruction value of the prediction reference point is used as the attribute prediction value, and the attribute residual value is the difference between the attribute original value and the attribute prediction value of the current point to be encoded; finally, the attribute residual value is quantized through the quantization unit 119, and The quantized residual information is input to the attribute entropy encoder 1110 to form an attribute code stream.
  • the embodiment of the present application also provides a point cloud decoder.
  • Figure 5 shows the framework of the point cloud compression reference platform PCRM provided by AVS.
  • the point cloud decoder 12 includes a geometric decoder: a geometric entropy decoder 121, Octree reconstruction unit 122, coordinate inverse quantization unit 123, and coordinate inverse translation unit 124.
  • Attribute decoder attribute entropy decoder 125, inverse quantization unit 126, second attribute prediction unit 127 and color space inverse transform unit 128.
  • geometry and attributes are also decoded separately.
  • the geometry code stream is first entropy decoded through the geometric entropy decoder 121 to obtain the geometric information of each node, and then the octree structure is constructed through the octree reconstruction unit 122 in the same way as the geometry encoding, combined with
  • the decoded geometry reconstructs the geometric information expressed through the octree structure after coordinate transformation.
  • the information is coordinate inverse quantized through the coordinate inverse quantization unit 123 and inversely translated through the coordinate inverse translation unit 124 to obtain the decoded geometry information.
  • it is input to the attribute decoder as additional information.
  • the Morton order is constructed in the same way as the encoding end.
  • the attribute code stream is entropy decoded through the attribute entropy decoder 125 to obtain the quantized residual information; then inverse quantization is performed through the inverse quantization unit 126.
  • Obtain the attribute residual value similarly, in the same manner as attribute encoding, obtain the attribute prediction value of the current to-be-decoded point through the second attribute prediction unit 127, and then add the attribute prediction value and the attribute residual value to recover
  • the attribute reconstruction value of the current point to be decoded (for example, YUV attribute value); finally, the decoding attribute information is obtained through the inverse color space transformation of the color space inverse transformation unit 128 .
  • test conditions There are 4 types of test conditions:
  • Condition 1 The geometric position is limited and lossy, and the attributes are lossy;
  • Condition 3 The geometric position is lossless, and the attributes are limited and lossy
  • Condition 4 The geometric position is lossless and the attributes are lossless.
  • the universal test sequence includes five categories: Cat1A, Cat1B, Cat1C, Cat2-frame and Cat3. Among them, Cat1A and Cat2-frame point clouds only contain reflectance attribute information, Cat1B and Cat3 point clouds only contain color attribute information, and Cat1C point clouds contain both color and reflectance attribute information.
  • the points in the point cloud are processed in a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.).
  • the prediction algorithm is first used to obtain the attribute prediction value, and the attribute prediction value is obtained based on the attribute value and attribute prediction.
  • the attribute residuals are obtained from the values, and then the attribute residuals are quantized to generate quantized residuals, and finally the quantized residuals are encoded;
  • the points in the point cloud are processed in a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.).
  • the prediction algorithm is first used to obtain the attribute prediction value, and then the decoding is performed to obtain the quantized residual. , then perform inverse quantization on the quantized residual, and finally obtain the attribute reconstruction value based on the attribute prediction value and the inverse-quantized attribute residual.
  • Attribute compression uses methods based on intra-frame prediction and discrete cosine transform (Discrete Cosine Transform, DCT). At this time, there is a maximum number of points when encoding the quantized transform coefficients.
  • DCT discrete Cosine Transform
  • the points in the point cloud are processed in a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.), and the entire point cloud is first divided into parts with a maximum length of Y (for example, 2) Several small groups, and then combine these small groups into several large groups (the number of points in each large group does not exceed Difference, perform DCT transformation on the attribute residuals in small groups, generate transformation coefficients, then quantize the transformation coefficients, generate quantized transformation coefficients, and finally encode the quantized transformation coefficients in large groups;
  • Y for example, 2
  • the points in the point cloud are processed in a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.), and the entire point cloud is first divided into parts with a maximum length of Y (for example, 2) Several small groups, and then combine these small groups into several large groups (the number of points in each large group does not exceed The predicted value is then inversely quantized and inversely transformed on the quantized transformation coefficient in small groups. Finally, the attribute reconstruction value is obtained based on the attribute predicted value and the inversely quantized and inversely transformed coefficient.
  • a certain order for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.
  • Attribute compression uses methods based on intra-frame prediction and DCT transformation.
  • encoding the quantized transformation coefficients there is no limit to the maximum number of points X at this time, that is, all coefficients Coding together:
  • the points in the point cloud are processed in a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.), and the entire point cloud is first divided into parts with a maximum length of Y (for example, 2) Several groups are formed, and then the prediction algorithm is used to obtain the attribute prediction value, and the attribute residual is obtained based on the attribute value and the attribute prediction value.
  • the attribute residual is DCT transformed in groups as a unit to generate the transformation coefficient, and then the transformation coefficient is quantified to generate the quantization
  • the final transformation coefficients, and finally the quantized transformation coefficients of the entire point cloud are encoded;
  • the points in the point cloud are processed in a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.), and the entire point cloud is first divided into parts with a maximum length of Y (for example, 2) Several groups are formed, decode and obtain the quantized transformation coefficients of the entire point cloud, and then use the prediction algorithm to obtain the attribute prediction values. Then, the quantized transformation coefficients are inversely quantized and inversely transformed in groups as a unit, and finally the attribute prediction values and inverse transformations are performed. The coefficients after quantization and inverse transformation are used to obtain attribute reconstruction values.
  • a certain order for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.
  • multi-layer wavelet transform is performed on the entire point cloud to generate transform coefficients, then the transform coefficients are quantized, the quantized transform coefficients are generated, and finally the quantized transform coefficients of the entire point cloud are encoded;
  • decoding obtains the quantized transformation coefficients of the entire point cloud, and then performs inverse quantization and inverse transformation on the quantized transformation coefficients to obtain attribute reconstruction values.
  • the prediction branch processes the points in the point cloud according to a certain order (for example, the original collection order of the point cloud, Morton order, Hilbert order, etc.).
  • the embodiment of the present application provides a coding and decoding method.
  • the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point are determined; the absolute value of the initial quantized residual satisfies the first preset condition.
  • determine the quantized residual absolute value of the current point according to the parity characteristics of the symbol and the initial quantized residual absolute value, determine the quantized residual absolute value of the current point; encode the quantized residual absolute value, and write the resulting coded bits into the code stream.
  • the code stream is parsed to determine the absolute value of the quantized residual at the current point; when the absolute value of the quantized residual meets the first preset condition, the quantized value of the current point is determined based on the parity characteristics of the absolute value of the quantized residual.
  • the sign of the residual determine the attribute reconstruction value of the current point based on the absolute value and sign of the quantized residual.
  • the parity characteristics based on the absolute value of the quantized residual can hide some symbols of the values to be encoded, that is, there is no need to encode these symbols, so as to reduce the codewords used when encoding attribute information; while on the decoding side, The corresponding symbol can be directly determined based on the parity and even characteristics of the absolute value of the quantized residual obtained by decoding; thus, the use of codewords can be reduced, the encoding and decoding efficiency of point cloud attributes can be improved, and the encoding and decoding performance of point cloud attributes can be improved.
  • FIG. 6 shows a schematic flowchart of a decoding method provided by an embodiment of the present application. As shown in Figure 6, the method may include:
  • S601 Analyze the code stream and determine the absolute value of the quantized residual at the current point.
  • the decoding method described in the embodiment of the present application specifically refers to a point cloud decoding method, and more specifically a point cloud attribute decoding method based on symbol hiding, in order to further reduce the codewords used when encoding attribute information.
  • This method can be applied to point cloud decoders (also simply called “decoders").
  • the point cloud to be processed includes at least one point.
  • a point in the point cloud to be processed when decoding the point, it can be used as a point to be decoded in the point cloud to be processed, and there are multiple decoded points around the point.
  • the current point is the point to be decoded that currently needs to be decoded among the at least one point.
  • each point in the point cloud to be processed corresponds to a geometric information and an attribute information; wherein, the geometric information represents the spatial relationship of the point, and the attribute information represents the attribute information of the point. .
  • the attribute information may be a color component, or may be reflectance, refractive index, or other attributes, which are not specifically limited in the embodiments of this application.
  • the attribute information when it is a color component, it can specifically be color information in any color space.
  • the attribute information may be color information in the RGB space, color information in the YUV space, color information in the YCbCr space, etc., which are not specifically limited in the embodiments of the present application.
  • the color component may include at least one of the following: a first color component, a second color component, and a third color component.
  • a first color component a second color component
  • a third color component a third color component.
  • the color component conforms to the RGB color space, then it can be determined that the first color component, the second color component and the third color component are respectively one of them: R component, G component, B component; if the color component conforms to the YUV color space, Then it can be determined that the first color component, the second color component and the third color component are each one of them: Y component, U component, V component; if the color component conforms to the YCbCr color space, then it can be determined that the first color component, the second color component The color component and the third color component are each one of them: Y component, Cb component, Cr component.
  • the first color component may be the R component
  • the second color component may be the G component
  • the third color component may be the B component
  • the first color component may be the G component
  • the third color component may be the G component
  • the second color component may be the B component, and the third color component may be the R component; or, the first color component may be the B component, the second color component may be the G component, the third color component may be the R component, etc.
  • this application The examples are not specifically limited either.
  • the decoder can process each point in the point cloud to be processed according to a preset decoding order.
  • the preset decoding order may be: the original collection order of point clouds, Morton order or Hilbert order, etc., which is not specifically limited in the embodiments of this application.
  • the first preset condition may be a preset judgment standard for determining whether to hide the symbol corresponding to the current point. For example, whether the absolute value of the quantized residual satisfies the first preset condition may be determined based on a comparison result between the absolute value of the quantized residual and a preset threshold. Therefore, in some embodiments, the method may further include:
  • the absolute value of the quantized residual is greater than or equal to the preset threshold, it is determined that the absolute value of the quantized residual satisfies the first preset condition
  • the preset threshold here can also be regarded as a judgment criterion for determining whether to hide the symbol corresponding to the current point.
  • the preset threshold can be represented by signH, and the value of the preset threshold can be set to 4, 5, 6, 8, etc.
  • the value of the preset threshold is equal to 4, but this is not specifically limited.
  • determining the sign of the quantized residual based on the parity characteristics of the absolute value of the quantized residual may include:
  • the decoding end when the symbol of the quantized residual is determined to be hidden, can determine the symbol based on the parity characteristics of the absolute value of the quantized residual. For example, if the absolute value of the quantized residual is an odd number, then the sign can be determined to be a negative sign, that is, the signed quantized residual value is a negative odd number; and/or if the absolute value of the quantized residual is an even number, then the sign can be determined is a positive sign, that is, the signed quantized residual value is a positive even number.
  • determining the sign of the quantized residual at the current point based on the parity characteristics of the absolute value of the quantized residual may include:
  • the decoder when the symbol of the quantized residual is determined to be hidden, the decoder can still determine the symbol based on the parity characteristics of the absolute value of the quantized residual. For example, if the absolute value of the quantized residual is an odd number, then the sign can be determined to be positive, that is, the signed quantized residual value is a positive odd number; and/or if the absolute value of the quantized residual is an even number, then the sign can be determined is a negative sign, that is, the signed quantized residual value is a negative even number.
  • determining the parity characteristics of the absolute value of the quantized residual may include: calculating the parity characteristics of the absolute value of the quantized residual to obtain the parity value; if the parity value is equal to the third value, then The absolute value of the quantized residual is determined to be an odd number; and/or, if the odd-even value is equal to the fourth value, the absolute value of the quantized residual is determined to be an even number.
  • the value of the third value is equal to 1, and the value of the fourth value is equal to 0.
  • the absolute value of the quantized residual is represented by resQ
  • the parity value is represented by parity.
  • the signed quantized residual value is an odd number greater than zero, it means that the signed quantized residual value is a positive odd number; if the signed quantized residual value is greater than If it is an even number of zero, it means that the signed quantized residual value is a positive even number; if the signed quantized residual value is an odd number less than zero, it means that the signed quantized residual value is a negative odd number; if the signed quantized residual value is an odd number If the difference is an even number less than zero, it means that the signed quantized residual value is a negative even number.
  • the decoder can determine the sign of the quantized residual at the current point based on the parity characteristics of the absolute value of the quantized residual.
  • the method may also include: parsing the code stream when the absolute value of the quantized residual does not meet the first preset condition. , determine the sign of the quantized residual at the current point.
  • the preset threshold as an example, if the absolute value of the quantized residual is less than the preset threshold, that is, the absolute value of the quantized residual does not meet the first preset condition, it means that the symbol will be written into the code stream, so that the decoder can obtain the symbol of the quantized residual through decoding.
  • analyzing the code stream and determining the sign of the quantized residual at the current point may include:
  • the value of the symbol identification information is the first value, it is determined that the symbol is a positive sign
  • the value of the symbol identification information is the second value, it is determined that the symbol is a negative sign.
  • the first value may be 1 and the second value may be 0; or, the first value may be 0 and the second value may be 1, without any limitation here.
  • the encoding end writes the symbols into the code stream according to the value of the symbol identification information.
  • the decoding end can obtain the value of the symbol identification information by parsing the code stream; and then determine whether the symbol is a positive sign or a negative sign based on the value of the symbol identification information. For example, assuming that the first value is 1 and the second value is 0, then when the value of the symbol identification information obtained by decoding is 1, it can be determined that the symbol is a positive sign; when the value of the symbol identification information obtained by decoding is When 0, the sign can be determined to be negative.
  • S603 Determine the attribute reconstruction value of the current point based on the absolute value and sign of the quantized residual.
  • the method may also include: predicting the attribute information of the current point and determining the attribute prediction value of the current point.
  • a prediction algorithm is used to perform prediction processing on the attribute information of the current point, and the attribute prediction value of the current point can be obtained, which is represented by A j ′.
  • j indicates that the jth point in the point cloud to be processed is the current point
  • the prediction algorithm can also include an intra-frame prediction algorithm and an inter-frame prediction algorithm.
  • determining the attribute reconstruction value of the current point based on the absolute value and sign of the quantized residual may include:
  • the attribute reconstruction value of the current point is determined.
  • the absolute value of the quantized residual needs to be inversely quantized first to obtain the decoded residual value, which can be represented by InvQ (resQ); then the signed decoding is determined based on the decoded residual value and symbol.
  • the residual value can be represented by sign*InvQ(resQ); in this way, based on the attribute prediction value and the signed decoded residual value, the attribute reconstruction value of the current point can be determined. You can use express.
  • determining the attribute reconstruction value of the current point based on the attribute prediction value and the signed decoding residual value may include: performing an addition operation on the attribute prediction value and the signed decoding residual value. , get the attribute reconstruction value of the current point.
  • the attribute reconstruction value of the current point can be obtained.
  • the calculation formula is as follows,
  • the color component may include at least one of the following: a first color component, a second color component, and a third color component. Since there is a correlation between different color components, for the color components, the cross-component attribute prediction value can also be included, represented by residualPrevComponent. Therefore, in some embodiments, the method may further include: when the attribute information is a color component, determining a cross-component attribute prediction value of the current point.
  • attribute information is reflectivity, refractive index, etc.
  • the reflectance does not include multiple components
  • the refractive index does not include multiple components
  • determining the attribute reconstruction value of the current point based on the attribute prediction value and the signed decoding residual value may include: , the signed decoding residual value and the cross-component attribute prediction value are added to obtain the attribute reconstruction value of the current point.
  • the attribute reconstruction value of the current point can be obtained.
  • the calculation formula is as follows,
  • the parity characteristics according to the absolute value of the quantized residual can be introduced to hide part of the symbols to be encoded; so that at the decoding end, part of the symbols to be encoded are The encoded symbols do not need to be decoded from the code stream, thus reducing the use of code words.
  • Embodiments of the present application provide a decoding method that determines the absolute value of the quantized residual at the current point by parsing the code stream; when the absolute value of the quantized residual satisfies the first preset condition, the absolute value of the quantized residual is determined based on the parity of the absolute value of the quantized residual. Characteristics, determine the sign of the quantized residual of the current point; determine the attribute reconstruction value of the current point based on the absolute value and sign of the quantized residual.
  • the corresponding symbol can be directly determined based on the parity characteristics of the decoded absolute value of the quantized residual; thus, the use of codewords can be reduced and the encoding of point cloud attributes can be improved. Decoding efficiency, while improving the encoding and decoding performance of point cloud attributes.
  • FIG. 7 shows a detailed flowchart of a decoding method provided by the embodiment of the present application.
  • the detailed process may include:
  • S701 Analyze the code stream and determine the absolute value of the quantized residual at the current point.
  • S703 Analyze the code stream and determine the sign of the quantized residual at the current point.
  • S705 Perform inverse quantization processing on the absolute value of the quantized residual to obtain a decoded residual value; and determine a signed decoded residual value based on the decoded residual value and sign.
  • S706 Determine the attribute prediction value of the current point, and determine the attribute reconstruction value of the current point based on the attribute prediction value and the signed decoding residual value.
  • S704 after comparing the absolute value of the quantized residual with the preset threshold, if the absolute value of the quantized residual is greater than or equal to the preset threshold, then S704 needs to be executed,
  • the sign is determined according to the odd and even characteristics of the absolute value of the quantized residual. For example, if the absolute value of the quantized residual is an odd number, the sign is negative; if the absolute value of the quantized residual is an even number, the sign is positive; otherwise, if If the absolute value of the quantized residual is less than the preset threshold, then S703 needs to be executed.
  • the symbol is decoded from the code stream. For example, if the value of the symbol is the first value, it is determined that the symbol is a positive sign; if the value of the symbol is If the value is the second value, the sign is determined to be negative.
  • the decoding process shown in Figure 7 needs to be executed once for the first color component, the second color component and the third color component respectively, and after determining the current point
  • the attribute prediction value, the signed decoding residual value and the cross-component attribute prediction value are added to obtain the attributes of the current point.
  • Rebuild value for attribute information such as reflectivity or refractive index
  • the decoding process shown in Figure 7 is only executed once, and there is no need to obtain additional cross-component attribute prediction values.
  • the attribute prediction value and signed The decoded residual values are added to obtain the attribute reconstruction value of the current point.
  • the decoder first, if the attribute information is a color component, the following steps are performed once for the three color components; if the attribute information is reflectance, the following steps are performed once for the reflectance. .
  • the specific process is as follows:
  • Table 1 shows a test result under the C1 test condition provided by the embodiment of the present application.
  • the C1 test condition is limited-lossy geometry, lossy attributes (limit-lossy geometry, lossy attributes);
  • the general test sequence is Cat1A and Cat1C;
  • End-to-End BD-AttrRate indicates that the end-to-end attribute value is based on the attribute code Streaming BD-Rate.
  • BD-Rate reflects the difference in the Peak Signal to Noise Ratio (PSNR) curves obtained in two situations (with or without using the technical solution of the embodiment of the present application).
  • PSNR Peak Signal to Noise Ratio
  • this technical solution provides a point cloud attribute encoding and decoding method based on symbol hiding.
  • the codewords required to encode attribute information can introduce symbols that hide part of the value to be encoded based on parity, so that the decoder can determine the corresponding symbol based on the parity characteristics of the absolute value of the quantized residual obtained by decoding; thus reducing codewords Use to improve the encoding and decoding efficiency of point cloud attributes and improve the encoding and decoding performance of point cloud attributes.
  • FIG. 8 shows a schematic flowchart of an encoding method provided by an embodiment of the present application. As shown in Figure 8, the method may include:
  • S801 Determine the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point.
  • the encoding method described in the embodiment of the present application specifically refers to a point cloud encoding method, and more specifically, a point cloud attribute encoding method based on symbol hiding, in order to further reduce the number of codewords used when encoding attribute information.
  • This method can be applied to point cloud encoders (also simply called “encoders").
  • the point cloud to be processed includes at least one point.
  • a point in the point cloud to be processed when encoding the point, it can be used as a point to be encoded in the point cloud to be processed, and there are multiple encoded points around the point.
  • the current point is the point to be encoded that currently needs to be encoded among the at least one point.
  • each point in the point cloud to be processed corresponds to a geometric information and an attribute information; wherein, the geometric information represents the spatial relationship of the point, and the attribute information represents the attribute information of the point. .
  • the attribute information may be a color component, or may be reflectance, refractive index, or other attributes, which are not specifically limited in the embodiments of this application.
  • the attribute information when it is a color component, it can specifically be color information in any color space.
  • the attribute information may be color information in RGB space, color information in YUV space, color information in YCbCr space, etc., which are not specifically limited in the embodiments of the present application.
  • the color component may include at least one of the following: a first color component, a second color component, and a third color component.
  • a first color component a second color component
  • a third color component a third color component.
  • the color component conforms to the RGB color space, then it can be determined that the first color component, the second color component and the third color component are respectively one of them: R component, G component, B component; if the color component conforms to the YUV color space, Then it can be determined that the first color component, the second color component and the third color component are each one of them: Y component, U component, V component; if the color component conforms to the YCbCr color space, then it can be determined that the first color component, the second color component The color component and the third color component are each one of them: Y component, Cb component, Cr component.
  • the first color component may be the R component
  • the second color component may be the G component
  • the third color component may be the B component
  • the first color component may be the G component
  • the third color component may be the G component
  • the second color component may be the B component, and the third color component may be the R component; or, the first color component may be the B component, the second color component may be the G component, the third color component may be the R component, etc.
  • this application The examples are not specifically limited either.
  • the decoder can process each point in the point cloud to be processed according to a preset encoding order.
  • the preset coding order may be: the original collection order of point clouds, Morton order, Hilbert order, etc., which is not specifically limited in the embodiments of this application.
  • the attribute value ie, the original value
  • the symbol of the current point can be determined. Specifically, if the attribute value is greater than zero, then the sign can be stated to be positive; otherwise, if the attribute value is less than zero, then the sign can be stated to be negative. It should be noted that the attribute values here carry positive and negative signs.
  • determining the initial quantized residual absolute value of the current point may include:
  • a prediction algorithm is used to perform prediction processing on the attribute information of the current point, and the attribute prediction value of the current point can be obtained, which is represented by A j ′.
  • j indicates that the jth point in the point cloud to be processed is the current point
  • the prediction algorithm can also include an intra-frame prediction algorithm and an inter-frame prediction algorithm.
  • the attribute value of the current point is represented by A j
  • the attribute residual value of the current point is represented by res. Then for the determination of res, for example, the calculation formula is as follows,
  • the attribute residual value can be quantized and the absolute value can be obtained to obtain the initial quantized residual absolute value, which can be expressed by resQ.
  • the first preset condition may be a preset judgment standard for determining whether to hide the symbol corresponding to the current point. For example, whether the initial quantized residual absolute value satisfies the first preset condition may be determined based on a comparison result between the initial quantized residual absolute value and a preset threshold. Therefore, in some embodiments, the method may further include:
  • the preset threshold here can also be regarded as a judgment criterion for determining whether to hide the symbol corresponding to the current point.
  • the preset threshold can be represented by signH, and the value of the preset threshold can be set to 4, 5, 6, 8, etc.
  • the value of the preset threshold is equal to 4, but this is not specifically limited.
  • the method may further include:
  • the value of the symbol hidden identification information is set to the first value
  • the value of the symbol hidden identification information is set to the second value.
  • the first value may be 1 and the second value may be 0; or the first value may be 0 and the second value may be 1; or the first value may be true and the second value may be is false; or, the first value can be false, and the second value can be true; there is no specific limitation in the embodiment of this application.
  • the value of the symbol hiding identification information may be used to indicate whether the current point hides the symbol of the initial quantized residual. For example, assuming that the first value is true and the second value is false, then if the absolute value of the initial quantization residual is greater than or equal to the preset threshold, it means that the symbol needs to be hidden. At this time, the value of the symbol hiding identification information can be set. is true; if the absolute value of the initial quantization residual is less than the preset threshold, it means that there is no need to hide the symbol. At this time, the value of the symbol hidden identification information can be set to false.
  • the method may further include: when the value of the symbol hidden identification information is the first value, determining the parity characteristics of the absolute value of the initial quantization residual.
  • determining the parity characteristics of the absolute value of the initial quantized residual may include:
  • parity value is equal to the third value, it is determined that the absolute value of the initial quantization residual is an odd number
  • parity value is equal to the fourth value, it is determined that the absolute value of the initial quantization residual is an even number.
  • the third value is equal to 1, and the fourth value is equal to 0.
  • parity the parity value of the absolute value of the initial quantized residual.
  • determining the quantized residual absolute value of the current point according to the sign and the parity characteristics of the initial quantized residual absolute value may include :
  • the signed initial quantized residual satisfies the second preset condition, then determine the absolute value of the initial quantized residual as the absolute value of the quantized residual at the current point;
  • the absolute value of the quantized residual at the current point is determined based on the initial quantized residual absolute value and the preset constant value.
  • the signed initial quantized residual after obtaining the signed initial quantized residual, it is determined whether the signed initial quantized residual satisfies the second preset condition, for example, whether the signed initial quantized residual is negative. Odd numbers, positive even numbers, etc. If the signed initial quantized residual meets the second preset condition, then the absolute value of the initial quantized residual is the absolute value of the quantized residual at the current point.
  • the parity and even characteristics of the absolute value of the quantized residual it can Determine the sign; and/or, if the signed initial quantized residual does not meet the second preset condition, then the absolute value of the initial quantized residual needs to be calculated to determine the absolute value of the quantized residual at the current point, and then according to the quantized The sign can be determined by the odd-even characteristic of the absolute value of the residual.
  • determining whether the signed initial quantized residual satisfies the second preset condition based on the sign and the parity characteristics of the absolute value of the initial quantized residual may include:
  • the signed initial quantized residual is obtained
  • the signed initial quantized residual is an even number greater than zero or an odd number less than zero, it is determined that the signed initial quantized residual satisfies the second preset condition; and/or,
  • the signed initial quantized residual is an odd number greater than zero or an even number smaller than zero, it is determined that the signed initial quantized residual does not satisfy the second preset condition.
  • determining whether the signed initial quantized residual satisfies the second preset condition based on the sign and the parity characteristics of the absolute value of the initial quantized residual may include:
  • the signed initial quantized residual is obtained
  • the signed initial quantized residual is an odd number greater than zero or an even number less than zero, it is determined that the signed initial quantized residual satisfies the second preset condition; and/or,
  • the signed initial quantized residual is an even number greater than zero or an odd number smaller than zero, it is determined that the signed initial quantized residual does not satisfy the second preset condition.
  • the signed initial quantized residual is first determined at this time; then, if the signed initial quantized residual is a positive odd number (an odd number greater than zero) or a negative even number (an odd number less than zero) even), then it can be determined that the signed initial quantized residual satisfies the second preset condition.
  • the symbol does not need to be written into the code stream; for the decoder, if the absolute value of the quantized residual obtained by decoding is an even number, then the symbol can be determined to be a negative sign; if the absolute value of the quantized residual obtained by decoding is an odd number , then the sign can be determined to be positive.
  • the method may also include:
  • the signed initial quantized residual is determined to be an odd number greater than zero
  • the signed initial quantized residual is determined to be an odd number less than zero
  • the signed initial quantized residual is determined to be an even number greater than zero
  • the signed initial quantized residual is determined to be an even number less than zero.
  • the signed initial quantized residual is an odd number greater than zero, which can also be called a positive odd number.
  • the signed initial quantization residual is an odd number less than zero, which can also be called a negative odd number; If the sign is negative, and the absolute value of the initial quantization residual is an odd number, then it can be determined that the signed initial quantization residual is an odd number less than zero, which can also be called a negative odd number; if the sign is positive, and the initial quantization If the absolute value of the residual is an even number, then it can be determined that the signed initial quantized residual is an even number greater than zero, which can also be called a positive even number; if the sign is negative, and the absolute value of the initial quantized residual is an even number, then it can be determined The signed initial quantized residual is an even number less than zero, which can also be called a negative even number.
  • the current point is determined based on the absolute value of the initial quantized residual and the preset constant value.
  • the absolute value of the quantized residual can include:
  • the quantized residual absolute value of the current point is determined.
  • the value of the preset constant value may be 1, but it may also be other values, and is not specifically limited here.
  • the absolute value of the initial quantized residual and the preset constant value need to be calculated, for example, plus one calculation. , minus one calculation and so on.
  • two candidate values can be obtained: the first candidate quantization residual absolute value and the second candidate quantization residual absolute value.
  • the former can be calculated by adding one to the absolute value of the initial quantized residual, represented by resQ + ; the latter can be calculated by subtracting one from the absolute value of the initial quantized residual, represented by resQ - .
  • the absolute value of the quantized residual at the current point is then determined from resQ + and resQ- by performing a distortion cost calculation.
  • determining the absolute value of the quantized residual at the current point based on the first candidate quantized residual absolute value and the second candidate quantized residual absolute value may include:
  • the quantization residual absolute value of the current point is determined from the first candidate quantization residual absolute value and the second candidate quantization residual absolute value.
  • determining the first candidate attribute reconstruction value based on the first candidate quantized residual absolute value, sign and attribute prediction value may include:
  • the signed first candidate reconstruction residual is obtained
  • the first candidate attribute reconstruction value is obtained by adding the signed first candidate reconstruction residual and the attribute prediction value.
  • the first candidate quantized residual absolute value needs to be inversely quantized first to obtain the first candidate reconstructed residual absolute value, represented by InvQ(resQ + ); then according to the sign and the first candidate reconstructed residual absolute value value, at this time the signed first candidate reconstruction residual can be represented by sign*InvQ(resQ + ); finally, by adding the signed first candidate reconstruction residual and the attribute prediction value, the first candidate attribute can be obtained Rebuild value.
  • the calculation formula is as follows:
  • determining the second candidate attribute reconstruction value based on the second candidate quantized residual absolute value, sign, and attribute prediction value may include:
  • the signed second candidate reconstruction residual is obtained
  • An addition operation is performed on the signed second candidate reconstruction residual and the attribute prediction value to obtain the second candidate attribute reconstruction value.
  • the second candidate reconstruction residual On the encoding side, it is first necessary to perform inverse quantization processing on the absolute value of the second candidate quantization residual to obtain the absolute value of the second candidate reconstruction residual, represented by InvQ (resQ - ); then according to the sign and the second candidate reconstruction residual Absolute value, at this time, the signed second candidate reconstruction residual can be represented by sign*InvQ(resQ - ); finally, by adding the signed second candidate reconstruction residual and the attribute prediction value, the second candidate can be obtained Property reconstruction value.
  • the calculation formula is as follows:
  • the attribute information is a color component
  • the color component includes at least one of the following: a first color component, a second color component, and a third color component; since there is an association between different color components, then for the color component
  • cross-component attribute prediction values can also be included here, represented by residualPrevComponent. Therefore, in some embodiments, the method may further include: when the attribute information is a color component, determining a cross-component attribute prediction value of the current point.
  • attribute information is reflectivity, refractive index, etc.
  • the reflectance does not include multiple components
  • the refractive index does not include multiple components
  • performing residual calculation based on the attribute value and attribute predicted value to determine the attribute residual value of the current point may include: performing residual calculation based on the attribute value, attribute predicted value and cross-component attribute predicted value. Difference calculation to determine the attribute residual value of the current point.
  • the attribute value of the current point is represented by A j
  • the attribute prediction value of the current point is represented by A j ′
  • the cross-component attribute prediction value of the current point is represented by residualPrevComponent
  • the attribute residual value of the current point is still represented by res represents, then for the determination of res, for example, the calculation formula is as follows,
  • the attribute residual value can be quantized and the absolute value can be obtained, thereby obtaining the initial quantized residual absolute value; the initial quantized residual absolute value can be calculated by adding one and subtracting one. , the first candidate quantization residual absolute value (resQ + ) and the second candidate quantization residual absolute value (resQ - ) can be obtained.
  • determining the first candidate attribute reconstruction value based on the first candidate quantized residual absolute value, sign and attribute prediction value may include:
  • the signed first candidate reconstruction residual is obtained
  • the first candidate attribute reconstruction value is obtained by adding the signed first candidate reconstruction residual, the attribute prediction value, and the cross-component attribute prediction value.
  • the first candidate quantized residual absolute value needs to be inversely quantized first to obtain the first candidate reconstructed residual absolute value, represented by InvQ(resQ + ); then according to the sign and the first candidate reconstructed residual absolute value value, at this time the signed first candidate reconstruction residual can be represented by sign*InvQ(resQ + ); finally, by adding the signed first candidate reconstruction residual, attribute prediction value and cross-component attribute prediction value,
  • the first candidate attribute reconstruction value can be obtained.
  • the calculation formula is as follows:
  • determining the second candidate attribute reconstruction value based on the second candidate quantized residual absolute value, sign, and attribute prediction value may include:
  • the signed second candidate reconstruction residual is obtained
  • the second candidate attribute reconstruction value is obtained by adding the signed second candidate reconstruction residual, the attribute prediction value, and the cross-component attribute prediction value.
  • the second candidate reconstruction residual On the encoding side, it is first necessary to perform inverse quantization processing on the absolute value of the second candidate quantization residual to obtain the absolute value of the second candidate reconstruction residual, represented by InvQ (resQ - ); then according to the sign and the second candidate reconstruction residual Absolute value.
  • the signed second candidate reconstruction residual can be represented by sign*InvQ(resQ - ); finally, the signed second candidate reconstruction residual, attribute prediction value and cross-component attribute prediction value are added.
  • the second candidate attribute reconstruction value can be obtained.
  • the calculation formula is as follows:
  • the first-generation value and the second-generation value corresponding to these two candidate values can be calculated; then based on the first-generation value and the second-generation value , the final absolute value of the quantized residual is determined from resQ + and resQ - .
  • calculating the distortion cost of the first candidate attribute reconstruction value and the attribute value to obtain the first generation value may include: reconstructing the value according to the first candidate attribute Calculate the absolute value of the difference with the attribute value to obtain the first absolute value of the difference, and use the first absolute value of the difference as the first generation value.
  • calculating the distortion cost of the second candidate attribute reconstruction value and the attribute value to obtain the second generation value may include: calculating the absolute value of the difference based on the second candidate attribute reconstruction value and the attribute value. Calculate and obtain the absolute value of the second difference, and use the absolute value of the second difference as the second generation value.
  • the first-generation value can be expressed as cost +
  • the second-generation value can be expressed as cost - .
  • the calculation formula for the first-generation value can be as follows,
  • the calculation formula for the second generation value can be as follows,
  • abs(x) represents the absolute value of x.
  • calculating the distortion cost on the first candidate attribute reconstruction value and the attribute value to obtain the first generation value may include:
  • the first generation value is obtained by adding the first difference absolute value and the first candidate quantized residual absolute value.
  • the calculation of the distortion cost of the second candidate attribute reconstruction value and the attribute value to obtain the second generation value may include:
  • the second difference absolute value and the second candidate quantized residual absolute value are added to obtain the second generation value.
  • the first-generation value can be expressed as cost +
  • the second-generation value can be expressed as cost -
  • the calculation formula for the first generation value can also be as follows,
  • the calculation formula for the second generation value can also be as follows,
  • abs(x) represents the absolute value of x.
  • calculating the distortion cost on the first candidate attribute reconstruction value and the attribute value to obtain the first-generation value may include:
  • the first generation value is obtained by performing a weighted sum operation on the absolute value of the first difference and the absolute value of the first candidate quantization residual according to the first factor and the second factor.
  • the calculation of the distortion cost of the second candidate attribute reconstruction value and the attribute value to obtain the second generation value may include:
  • a weighted sum operation is performed on the absolute value of the second difference and the absolute value of the second candidate quantization residual according to the third factor and the fourth factor to obtain the second generation value.
  • the first factor can be expressed as ⁇ 1, the second factor can be expressed as ⁇ 1; the third factor can be expressed as ⁇ 2, and the fourth factor can be expressed as ⁇ 2.
  • the first-generation value can be expressed by cost +
  • the second-generation value can be expressed by cost - .
  • the calculation formula for the second generation value can also be as follows,
  • abs(x) represents the absolute value of x.
  • the method may further include: determining the absolute value of the first candidate quantization residual as the first-generation value.
  • the method may further include: determining the absolute value of the second candidate quantization residual as the second generation value.
  • the first generation value can be directly determined based on the absolute value of the first candidate quantization residual.
  • the distortion cost formula can also be as follows:
  • the value can be determined directly based on the absolute value of the second candidate quantization residual.
  • the distortion cost formula can also be as follows:
  • the calculation of the distortion cost may be to calculate the distortion cost between the candidate attribute reconstruction value and the original attribute value, or it may be to perform rate distortion on the candidate attribute reconstruction value and the original attribute value.
  • the cost calculation can either use the weighted sum of the candidate attribute reconstruction value and the original attribute value to calculate the distortion cost, or it can use resQ + and resQ - to calculate the distortion cost, or even other distortion cost methods, which are not discussed here.
  • the candidate attribute reconstruction value may be the first candidate attribute reconstruction value or the second candidate attribute reconstruction value.
  • the absolute value of the quantized residual at the current point can be determined based on the size of the cost value, and then the decoding end can The symbol is determined based on the parity characteristics of the absolute value of the quantized residual obtained by decoding.
  • determining the absolute value of the quantized residual at the current point from the first candidate quantized residual absolute value and the second candidate quantized residual absolute value according to the first generation value and the second generation value may include :
  • the second candidate quantized residual absolute value is determined as the quantized residual of the current point. absolute value
  • the first candidate quantization residual absolute value is determined as the quantization of the current point. The absolute value of the residual.
  • the third preset condition and the fourth preset condition are used to determine whether the absolute value of the quantized residual at the current point is set to the first candidate absolute value of the quantized residual or to the third candidate.
  • the absolute value of the two candidate quantized residuals may also include:
  • the second-generation value is greater than the first-generation value, it is determined that the first-generation value and the second-generation value do not meet the third preset condition.
  • whether the first-generation value and the second-generation value meet the third preset condition can be determined based on the comparison between the second-generation value and the first-generation value. For example, if the second generation value is less than or equal to the first generation value, then it can be determined that the first generation value and the second generation value meet the third preset condition; otherwise, if the second generation value is greater than the first generation value, then It can be determined that the first-generation value and the second-generation value do not satisfy the third preset condition.
  • the embodiments of this application will not specifically limit it.
  • the method may further include:
  • whether the second candidate quantization residual absolute value satisfies the fourth preset condition can be determined based on the comparison result of the second candidate quantization residual absolute value and the preset threshold. For example, if the absolute value of the second candidate quantization residual is greater than or equal to the preset threshold, it may be determined that the second candidate quantization residual absolute value satisfies the fourth preset condition; otherwise, if the second candidate quantization residual absolute value is less than If the threshold is preset, then it can be determined that the absolute value of the second candidate quantization residual does not satisfy the fourth preset condition.
  • the embodiment of this application does not specifically limit it.
  • determining the absolute value of the quantization residual at the current point from the first candidate quantization residual absolute value and the second candidate quantization residual absolute value may include:
  • the second candidate quantized residual absolute value is determined as the quantized residual absolute value of the current point
  • the first candidate quantized residual absolute value is determined as the quantized residual absolute value of the current point.
  • the first-generation value is represented by cost +
  • the second-generation value is represented by cost -
  • the absolute value of the second candidate quantized residual is represented by resQ -
  • the preset threshold is represented by signH.
  • cost - ⁇ cost + and resQ - ⁇ signH then the absolute value of the quantized residual can be set to resQ - , that is, the absolute value of the initial quantized residual is reduced by one; otherwise, if cost - > cost + or resQ - ⁇ signH , then the absolute value of the quantized residual can be set to resQ + , that is, the absolute value of the initial quantized residual plus one.
  • the cross-component attribute prediction value also needs to be considered in order to determine the new attribute residual value and the corresponding quantized residual absolute value.
  • the symbol when the absolute value of the initial quantized residual meets the first preset condition, it is determined that the symbol needs to be hidden; at this time, it is only necessary to encode the absolute value of the quantized residual at the current point and write the resulting coded bits. Input code stream. Subsequently, at the decoding end, after decoding to obtain the absolute value of the quantized residual, if the absolute value of the quantized residual satisfies the first preset condition, the symbol can be determined based on the parity characteristics of the absolute value of the quantized residual.
  • the method may further include:
  • the absolute value of the initial quantized residual is used as the absolute value of the quantized residual at the current point;
  • determining the value of symbol identification information may include:
  • the sign is a negative sign, it is determined that the value of the sign identification information is the second value.
  • the first value may be 1 and the second value may be 0; or, the first value may be 0 and the second value may be 1, which are not specifically limited here.
  • the encoding end can write the value of the symbol identification information into the code stream, so that the decoding end can parse the code stream. Determine whether the sign is positive or negative. For example, if 1 is used to represent that the symbol is positive and 0 is used to represent that the symbol is negative, then if the symbol is positive, the value of the symbol identification information can be set to 1; and/or, if the symbol is negative number, you can set the value of the symbol identification information to 0.
  • the absolute value of the initial quantization residual at the current point can be compared with the preset threshold, and then some hidden parts to be hidden according to the parity characteristics can be introduced. Encoded symbols; so that at the decoding end, some of the symbols to be encoded do not need to be decoded from the code stream, thereby reducing the use of codewords.
  • the embodiment of the present application provides a coding method by determining the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point; when the absolute value of the initial quantized residual satisfies the first preset condition, According to the parity characteristics of the symbol and the initial quantized residual absolute value, the quantized residual absolute value of the current point is determined; the quantized residual absolute value is encoded, and the resulting coded bits are written into the code stream.
  • the parity characteristics based on the absolute value of the quantized residual can hide the symbols of some of the values to be encoded, that is, there is no need to encode these symbols, so as to reduce the number of code words used when encoding attribute information; thus, the number of code words can be reduced Use to improve the encoding and decoding efficiency of point cloud attributes and improve the encoding and decoding performance of point cloud attributes.
  • FIG. 9 shows a detailed flowchart of an encoding method provided by the embodiment of the present application.
  • the detailed process may include:
  • S901 Determine the attribute prediction value of the current point.
  • S902 Determine the attribute residual value of the current point based on the attribute value and attribute prediction value of the current point.
  • S903 Quantify the attribute residual value and calculate the absolute value to obtain the initial quantized residual absolute value of the current point.
  • S904 Compare the absolute value of the initial quantization residual with the preset threshold.
  • S905 If the signed initial quantization residual does not meet the second preset condition, obtain two candidate values: the first candidate quantization residual absolute value and the second candidate quantization residual absolute value; where, the first candidate quantization residual absolute value The absolute value of the residual is calculated by adding one based on the absolute value of the initial quantized residual, and the absolute value of the second candidate quantized residual is calculated by subtracting one based on the absolute value of the initial quantized residual.
  • S906 Perform inverse quantization processing on the absolute value of the first candidate quantized residual and the absolute value of the second candidate quantized residual respectively, and determine the signed first candidate reconstruction residual and the signed second candidate reconstruction residual; and according to the band
  • the first candidate attribute reconstruction value is determined based on the signed first candidate reconstruction residual and the attribute prediction value
  • the second candidate attribute reconstruction value is determined based on the signed second candidate reconstruction residual and the attribute prediction value.
  • S907 Determine the first generation value corresponding to the first candidate attribute reconstruction value and the second generation value corresponding to the second candidate attribute reconstruction value based on the distortion cost method; based on the first generation value and the second generation value, quantify the residual value from the first candidate
  • the quantized residual absolute value of the current point is determined from the difference absolute value and the second candidate quantized residual absolute value.
  • S909 Encode the absolute value of the quantization residual, and write the resulting encoded bits into the code stream.
  • S910 Use the initial quantized residual absolute value as the quantized residual absolute value of the current point, encode the value of the symbol identification information and the quantized residual absolute value, and write the resulting coded bits into the code stream.
  • the signed initial quantized residual when the absolute value of the initial quantized residual is greater than or equal to the preset threshold, if the signed initial quantized residual does not meet the second preset condition (for example, signed The initial quantized residual is a positive odd number or a negative even number), then S905 to S909 can be executed; if the signed initial quantized residual meets the second preset condition (for example, the signed initial quantized residual is a negative odd number or a positive even number) ), then only S909 needs to be executed.
  • the absolute value of the quantized residual obtained by decoding is an odd number, the sign is negative; if the absolute value of the quantized residual obtained by decoding is an even number, the sign is positive.
  • the absolute value of the initial quantized residual is greater than or equal to the preset threshold
  • the signed initial quantized residual does not satisfy the second preset condition (for example, the signed initial quantized residual is a negative odd number or a positive even number )
  • S905 to S909 can also be executed; if the signed initial quantized residual meets the second preset condition (for example, the signed initial quantized residual is a positive odd number or a negative even number), then only S909 needs to be executed at this time .
  • the absolute value of the quantized residual obtained by decoding is an odd number, the sign is positive; if the absolute value of the quantized residual obtained by decoding is an even number, the sign is negative.
  • the encoding end may also be provided with symbolic hidden identification information.
  • the symbol hiding identification information can be set to true, but the value of the symbol hiding identification information does not need to be written into the code stream.
  • the distortion cost may be calculated between the candidate attribute reconstruction value and the original attribute value, or the candidate attribute reconstruction value and the original attribute value may be calculated based on the ratio.
  • Distortion cost calculation can either use the weighted sum of the candidate attribute reconstruction value and the original attribute value to calculate the distortion cost, or can use resQ + and resQ - to calculate the distortion cost, or even other distortion cost methods, which are not mentioned here. No specific limitation is made.
  • the candidate attribute reconstruction value may be the first candidate attribute reconstruction value or the second candidate attribute reconstruction value.
  • the encoding process shown in Figure 9 needs to be executed once for the first color component, the second color component and the third color component, and after determining the current point
  • additional cross-component attribute prediction values need to be obtained.
  • attribute information such as reflectivity or refractive index
  • the encoding process shown in Figure 9 is only executed once, and there is no need to obtain additional cross-component attribute prediction values.
  • the attribute information is a color component
  • the following steps are performed once for the three color components
  • the attribute information is reflectance
  • the following steps are performed once for the reflectance.
  • the attribute residual res can be obtained, as follows:
  • step e Compare the absolute value of the initial quantized residual with the preset threshold (represented by signH, for example, it can be set to 4). If the absolute value of the initial quantized residual is greater than or equal to the preset threshold, perform step e), otherwise perform step e).
  • the preset threshold represented by signH, for example, it can be set to 4.
  • step 4 If the signed initial quantized residual is a positive odd number or a negative even number, then perform step 4), otherwise jump to step f);
  • the absolute value of the quantized residual at the current point can be set to the absolute value of the initial quantized residual minus one, otherwise the absolute value of the quantized residual at the current point can be set to the initial quantized Add one to the absolute value of the residual (it should be noted that for the color component, the cross-component attribute prediction value needs to be considered), and then perform step f);
  • the signed quantized residual sign*resQ needs to be encoded, that is, the value of sign and the absolute value of the quantized residual
  • this technical solution provides a point cloud attribute encoding method based on symbol hiding.
  • the codewords required for attribute information can introduce symbols that hide part of the value to be encoded based on parity, so that the subsequent decoding end can determine the corresponding symbol based on the parity characteristics of the absolute value of the quantized residual obtained by decoding; thus, the number of codewords can be reduced Use to improve the encoding and decoding efficiency of point cloud attributes and improve the encoding and decoding performance of point cloud attributes.
  • the embodiment of the present application provides a code stream, which is generated by bit encoding based on the information to be encoded.
  • the information to be encoded at least includes: the absolute value of the quantized residual of the current point, or the absolute value of the quantized residual of the current point and the corresponding symbol identification information.
  • FIG. 10 shows a schematic structural diagram of an encoder provided by an embodiment of the present application.
  • the encoder 100 may include: a first determining unit 1001 and an encoding unit 1002; wherein,
  • the first determination unit 1001 is configured to determine the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point; and when the absolute value of the initial quantized residual satisfies the first preset condition, according to the sign and The parity characteristics of the initial quantized residual absolute value determine the quantized residual absolute value of the current point;
  • the encoding unit 1002 is configured to encode the absolute value of the quantization residual and write the resulting encoded bits into the code stream.
  • the first determination unit 1001 is further configured to use the initial quantized residual absolute value as the quantized residual absolute value of the current point when the initial quantized residual absolute value does not meet the first preset condition;
  • the encoding unit 1002 is also configured to determine the value of the symbol identification information, encode the value of the symbol identification information and the absolute value of the quantization residual, and write the resulting encoded bits into the code stream.
  • the first determining unit 1001 is also configured to determine that the absolute value of the initial quantized residual satisfies the first preset condition if the absolute value of the initial quantized residual is greater than or equal to the preset threshold; if the absolute value of the initial quantized residual is less than the preset threshold, it is determined that the absolute value of the initial quantized residual does not meet the first preset condition.
  • the "unit" may be part of a circuit, part of a processor, part of a program or software, etc., and of course may also be a module, or may be non-modular.
  • each component in this embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.
  • the above integrated units can be implemented in the form of hardware or software function modules.
  • the integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium.
  • the technical solution of this embodiment is essentially either The part that contributes to the existing technology or all or part of the technical solution can be embodied in the form of a software product.
  • the computer software product is stored in a storage medium and includes a number of instructions to make a computer device (can It is a personal computer, server, or network device, etc.) or processor that executes all or part of the steps of the method described in this embodiment.
  • the aforementioned storage media include: U disk, mobile hard disk, Read Only Memory (ROM), Random Access Memory (RAM), magnetic disk or optical disk and other media that can store program code.
  • embodiments of the present application provide a computer-readable storage medium for use in the encoder 100.
  • the computer-readable storage medium stores a computer program.
  • the computer program is executed by the first processor, any of the foregoing embodiments can be implemented. method described in one item.
  • the encoder 100 may include: a first communication interface 1101 , a first memory 1102 and a first processor 1103 ; the various components are coupled together through a first bus system 1104 .
  • the first bus system 1104 is used to implement connection communication between these components.
  • the first bus system 1104 also includes a power bus, a control bus and a status signal bus.
  • various buses are labeled as the first bus system 1104 in FIG. 11 . in,
  • the first communication interface 1101 is used for receiving and sending signals during the process of sending and receiving information with other external network elements;
  • the first memory 1102 is used to store a computer program capable of running on the first processor 1103;
  • the first processor 1103 is configured to execute: when running the computer program:
  • the first memory 1102 in the embodiment of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories.
  • non-volatile memory can be read-only memory (Read-Only Memory, ROM), programmable read-only memory (Programmable ROM, PROM), erasable programmable read-only memory (Erasable PROM, EPROM), electrically removable memory. Erase programmable read-only memory (Electrically EPROM, EEPROM) or flash memory.
  • Volatile memory may be Random Access Memory (RAM), which is used as an external cache.
  • RAM static random access memory
  • DRAM dynamic random access memory
  • DRAM synchronous dynamic random access memory
  • SDRAM double data rate synchronous dynamic random access memory
  • Double Data Rate SDRAM DDRSDRAM
  • enhanced SDRAM ESDRAM
  • Synchlink DRAM SLDRAM
  • Direct Rambus RAM DRRAM
  • the first memory 1102 of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.
  • the first processor 1103 may be an integrated circuit chip with signal processing capabilities. During the implementation process, each step of the above method can be completed by instructions in the form of hardware integrated logic circuits or software in the first processor 1103 .
  • the above-mentioned first processor 1103 can be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), or an off-the-shelf programmable gate array (Field Programmable Gate Array, FPGA). or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.
  • DSP Digital Signal Processor
  • ASIC Application Specific Integrated Circuit
  • FPGA Field Programmable Gate Array
  • a general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.
  • the steps of the method disclosed in conjunction with the embodiments of the present application can be directly implemented by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor.
  • the software module can be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other mature storage media in this field.
  • the storage medium is located in the first memory 1102.
  • the first processor 1103 reads the information in the first memory 1102 and completes the steps of the above method in combination with its hardware.
  • the embodiments described in this application can be implemented using hardware, software, firmware, middleware, microcode, or a combination thereof.
  • the processing unit can be implemented in one or more Application Specific Integrated Circuits (ASIC), Digital Signal Processing (DSP), Digital Signal Processing Device (DSP Device, DSPD), programmable Logic device (Programmable Logic Device, PLD), Field-Programmable Gate Array (FPGA), general-purpose processor, controller, microcontroller, microprocessor, and other devices used to perform the functions described in this application electronic unit or combination thereof.
  • ASIC Application Specific Integrated Circuits
  • DSP Digital Signal Processing
  • DSP Device Digital Signal Processing Device
  • DSPD Digital Signal Processing Device
  • PLD programmable Logic Device
  • FPGA Field-Programmable Gate Array
  • the technology described in this application can be implemented through modules (such as procedures, functions, etc.) that perform the functions described in this application.
  • Software code may be stored in memory and executed by a processor.
  • the memory can be implemented in the processor or external to the processor.
  • the first processor 1103 is further configured to perform the method described in any one of the preceding embodiments when running the computer program.
  • This embodiment provides an encoder in which the symbols of some values to be encoded can be hidden based on the parity characteristics of the absolute value of the quantized residual, that is, there is no need to encode these symbols, so as to reduce the time required for encoding attribute information.
  • the code words used thereby reducing the use of code words, improving the coding efficiency of point cloud attributes, and improving the coding performance of point cloud attributes.
  • FIG. 12 shows a schematic structural diagram of a decoder 120 provided by an embodiment of the present application.
  • the decoder 120 may include: a decoding unit 1201 and a second determination unit 1202; wherein,
  • the decoding unit 1201 is configured to parse the code stream and determine the absolute value of the quantization residual at the current point;
  • the second determination unit 1202 is configured to determine the sign of the quantized residual at the current point according to the parity characteristics of the absolute value of the quantized residual when the absolute value of the quantized residual satisfies the first preset condition; and based on the absolute value of the quantized residual Value and sign, determine the attribute reconstruction value of the current point.
  • the decoding unit 1201 is further configured to parse the code stream and determine the sign of the quantized residual at the current point when the absolute value of the quantized residual does not meet the first preset condition.
  • the decoding unit 1201 is also configured to parse the code stream and obtain the value of the symbol identification information
  • the second determining unit 1202 is further configured to determine that the symbol is a positive sign if the value of the symbol identification information is a first value; and to determine that the symbol is a positive sign if the value of the symbol identification information is a second value. The sign is negative.
  • the "unit" may be part of a circuit, part of a processor, part of a program or software, etc., and of course may also be a module, or may be non-modular.
  • each component in this embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.
  • the above integrated units can be implemented in the form of hardware or software function modules.
  • the integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium.
  • this embodiment provides a computer-readable storage medium for use in the decoder 120.
  • the computer-readable storage medium stores a computer program.
  • the computer program is executed by the second processor, the foregoing embodiments are implemented. any one of the methods.
  • the decoder 120 may include: a second communication interface 1301, a second memory 1302, and a second processor 1303; the various components are coupled together through a second bus system 1304.
  • the second bus system 1304 is used to implement connection communication between these components.
  • the second bus system 1304 also includes a power bus, a control bus and a status signal bus.
  • various buses are labeled as second bus system 1304 in FIG. 13 . in,
  • the second communication interface 1301 is used for receiving and sending signals during the process of sending and receiving information with other external network elements;
  • the second memory 1302 is used to store a computer program capable of running on the second processor 1303;
  • the second processor 1303 is configured to execute: when running the computer program:
  • the attribute reconstruction value of the current point is determined.
  • the second processor 1303 is further configured to perform the method described in any one of the preceding embodiments when running the computer program.
  • This embodiment provides a decoder, in which the parity and even characteristics of the absolute value of the quantized residual obtained by decoding are used to determine the corresponding symbol; thereby reducing the use of codewords and improving the encoding and decoding efficiency of point cloud attributes. , while improving the encoding and decoding performance of point cloud attributes.
  • FIG. 14 shows a schematic structural diagram of a coding and decoding system provided by an embodiment of the present application.
  • the encoding and decoding system 140 may include an encoder 1401 and a decoder 1402.
  • the encoder 1401 may be the encoder described in any of the preceding embodiments
  • the decoder 1402 may be the decoder described in any of the preceding embodiments.
  • the encoder 1401 in the encoder 1401, based on the parity characteristics of the absolute value of the quantized residual, some symbols of the values to be encoded can be hidden, that is, there is no need to encode these partial symbols to reduce the properties.
  • the code words used when encoding information; in the decoder 1402, the corresponding symbols can be directly determined based on the parity characteristics of the absolute value of the quantized residual obtained by decoding; thus, the use of code words can be reduced and the encoding and decoding of point cloud attributes can be improved. efficiency, while improving the encoding and decoding performance of point cloud attributes.
  • the absolute value of the initial quantized residual of the current point and the sign of the initial quantized residual of the current point are determined; when the absolute value of the initial quantized residual satisfies the first preset condition, according to the sign and the parity characteristics of the initial quantized residual absolute value, determine the quantized residual absolute value of the current point; encode the quantized residual absolute value, and write the resulting coded bits into the code stream.
  • the code stream is parsed to determine the absolute value of the quantized residual at the current point; when the absolute value of the quantized residual meets the first preset condition, the quantized residual at the current point is determined based on the parity characteristics of the absolute value of the quantized residual.
  • the sign of the difference determines the attribute reconstruction value of the current point based on the absolute value and sign of the quantized residual.
  • the parity characteristics based on the absolute value of the quantized residual can hide some symbols of the values to be encoded, that is, there is no need to encode these symbols, so as to reduce the codewords used when encoding attribute information; while on the decoding side, The corresponding symbol can be directly determined based on the parity and even characteristics of the absolute value of the quantized residual obtained by decoding; thus, the use of codewords can be reduced, the encoding and decoding efficiency of point cloud attributes can be improved, and the encoding and decoding performance of point cloud attributes can be improved.

Abstract

Selon des modes de réalisation, la présente invention concerne un procédé de codage, un procédé de décodage, un flux de code, des codeurs, des décodeurs et un support de stockage. Le procédé de décodage consiste à : analyser un flux de code, et déterminer la valeur absolue d'un résidu quantifié du point courant ; lorsque la valeur absolue du résidu quantifié satisfait une première condition prédéfinie, déterminer un signe du résidu quantifié du point courant en fonction de la caractéristique de parité de la valeur absolue du résidu quantifié ; et déterminer une valeur reconstruite de l'attribut du point courant en fonction de la valeur absolue du résidu quantifié et du signe. Ainsi, un signe est caché sur la base de la caractéristique de parité d'une valeur absolue d'un résidu quantifié, de sorte que le nombre de mots de code utilisés lors du codage d'informations d'attribut peut être réduit, et l'efficacité de codage et de décodage peut être améliorée.
PCT/CN2022/103817 2022-07-05 2022-07-05 Procédé de codage, procédé de décodage, flux de code, codeurs, décodeurs et support de stockage WO2024007144A1 (fr)

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US20190311500A1 (en) * 2018-04-10 2019-10-10 Apple Inc. Point cloud compression
CN112995662A (zh) * 2021-03-12 2021-06-18 北京大学深圳研究生院 一种点云的属性熵编码和熵解码的方法及设备
WO2022131948A1 (fr) * 2020-12-14 2022-06-23 Huawei Technologies Co., Ltd. Dispositifs et procédés de codage séquentiel pour compression de nuage de points

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US20130272424A1 (en) * 2012-04-16 2013-10-17 Qualcomm Incorporated Sign hiding techniques for quantized transform coefficients in video coding
CN104380740A (zh) * 2012-06-29 2015-02-25 索尼公司 编码装置、编码方法、解码装置和解码方法
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