Patent Application
20240242390
Embodiments relate to a method and device for processing point cloud content.
Point cloud content is content represented by a point cloud, which is a set of points belonging to a coordinate system representing a three-dimensional space. The point cloud content may express media configured in three dimensions, and is used to provide various services such as virtual reality (VR), augmented reality (AR), mixed reality (MR), and self-driving services. However, tens of thousands to hundreds of thousands of point data are required to represent point cloud content. Therefore, there is a need for a method for efficiently processing a large amount of point data.
Embodiments provide a device and method for efficiently processing point cloud data. Embodiments provide a point cloud data processing method and device for addressing latency and encoding/decoding complexity.
The technical scope of the embodiments is not limited to the aforementioned technical objects, and may be extended to other technical objects that may be inferred by those skilled in the art based on the entire contents disclosed herein.
To achieve these objects and other advantages and in accordance with the purpose of the disclosure, as embodied and broadly described herein, a method of transmitting point cloud data may include encoding the point cloud data, and transmitting a bitstream containing the point cloud data. A method of receiving point cloud data according to embodiments may include receiving a bitstream containing point cloud data and decoding the point cloud data.
Devices and methods according to embodiments may process point cloud data with high efficiency.
The devices and methods according to the embodiments may provide a high-quality point cloud service.
The devices and methods according to the embodiments may provide point cloud content for providing general-purpose services such as a VR service and a self-driving service.
The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the disclosure and together with the description serve to explain the principle of the disclosure. For a better understanding of various embodiments described below, reference should be made to the description of the following embodiments in connection with the accompanying drawings. The same reference numbers will be used throughout the drawings to refer to the same or like parts. In the drawings:
Reference will now be made in detail to the preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present disclosure, rather than to show the only embodiments that may be implemented according to the present disclosure. The following detailed description includes specific details in order to provide a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure may be practiced without such specific details.
Although most terms used in the present disclosure have been selected from general ones widely used in the art, some terms have been arbitrarily selected by the applicant and their meanings are explained in detail in the following description as needed. Thus, the present disclosure should be understood based upon the intended meanings of the terms rather than their simple names or meanings.
The point cloud content providing system illustrated in
The point cloud data transmission device 10000 according to the embodiments may secure and process point cloud video (or point cloud content) and transmit the same. According to embodiments, the transmission device 10000 may include a fixed station, a base transceiver system (BTS), a network, an artificial intelligence (AI) device and/or system, a robot, an AR/VR/XR device and/or server. According to embodiments, the transmission device 10000 may include a device, a robot, a vehicle, an AR/VR/XR device, a portable device, a home appliance, an Internet of Thing (IoT) device, and an AI device/server which are configured to perform communication with a base station and/or other wireless devices using a radio access technology (e.g., 5G New RAT (NR), Long Term Evolution (LTE)).
The transmission device 10000 according to the embodiments includes a point cloud video acquirer (Point Cloud Video Acquisition) 10001, a point cloud video encoder 10002, and/or a transmitter (or communication module) 10003.
The point cloud video acquirer 10001 according to the embodiments acquires a point cloud video through a processing process such as capture, synthesis, or generation. The point cloud video is point cloud content represented by a point cloud, which is a set of points positioned in a 3D space, and may be referred to as point cloud video data. The point cloud video according to the embodiments may include one or more frames. One frame represents a still image/picture. Therefore, the point cloud video may include a point cloud image/frame/picture, and may be referred to as a point cloud image, frame, or picture.
The point cloud video encoder 10002 according to the embodiments encodes the acquired point cloud video data. The point cloud video encoder 10002 may encode the point cloud video data based on point cloud compression coding. The point cloud compression coding according to the embodiments may include geometry-based point cloud compression (G-PCC) coding and/or video-based point cloud compression (V-PCC) coding or next-generation coding. The point cloud compression coding according to the embodiments is not limited to the above-described embodiment. The point cloud video encoder 10002 may output a bitstream containing the encoded point cloud video data. The bitstream may contain not only the encoded point cloud video data, but also signaling information related to encoding of the point cloud video data.
The transmitter 10003 according to the embodiments transmits the bitstream containing the encoded point cloud video data. The bitstream according to the embodiments is encapsulated in a file or segment (e.g., a streaming segment), and is transmitted over various networks such as a broadcasting network and/or a broadband network. Although not shown in the figure, the transmission device 10000 may include an encapsulator (or an encapsulation module) configured to perform an encapsulation operation. According to embodiments, the encapsulator may be included in the transmitter 10003. According to embodiments, the file or segment may be transmitted to the reception device 10004 over a network, or stored in a digital storage medium (e.g., USB, SD, CD, DVD, Blu-ray, HDD, SSD, etc.). The transmitter 10003 according to the embodiments is capable of wired/wireless communication with the reception device 10004 (or the receiver 10005) over a network of 4G, 5G, 6G, etc. In addition, the transmitter may perform a necessary data processing operation according to the network system (e.g., a 4G, 5G or 6G communication network system). The transmission device 10000 may transmit the encapsulated data in an on-demand manner.
The reception device 10004 according to the embodiments includes a receiver 10005, a point cloud video decoder 10006, and/or a renderer 10007. According to embodiments, the reception device 10004 may include a device, a robot, a vehicle, an AR/VR/XR device, a portable device, a home appliance, an Internet of Things (IoT) device, and an AI device/server which are configured to perform communication with a base station and/or other wireless devices using a radio access technology (e.g., 5G New RAT (NR), Long Term Evolution (LTE)).
The receiver 10005 according to the embodiments receives the bitstream containing the point cloud video data or the file/segment in which the bitstream is encapsulated from the network or storage medium. The receiver 10005 may perform necessary data processing according to the network system (e.g., a communication network system of 4G, 5G, 6G, etc.). The receiver 10005 according to the embodiments may decapsulate the received file/segment and output a bitstream. According to embodiments, the receiver 10005 may include a decapsulator (or a decapsulation module) configured to perform a decapsulation operation. The decapsulator may be implemented as an element (or component) separate from the receiver 10005.
The point cloud video decoder 10006 decodes the bitstream containing the point cloud video data. The point cloud video decoder 10006 may decode the point cloud video data according to the method by which the point cloud video data is encoded (e.g., in a reverse process of the operation of the point cloud video encoder 10002). Accordingly, the point cloud video decoder 10006 may decode the point cloud video data by performing point cloud decompression coding, which is the reverse process of the point cloud compression. The point cloud decompression coding includes G-PCC coding.
The renderer 10007 renders the decoded point cloud video data. The renderer 10007 may output point cloud content by rendering not only the point cloud video data but also audio data. According to embodiments, the renderer 10007 may include a display configured to display the point cloud content. According to embodiments, the display may be implemented as a separate device or component rather than being included in the renderer 10007.
The arrows indicated by dotted lines in the drawing represent a transmission path of feedback information acquired by the reception device 10004. The feedback information is information for reflecting interactivity with a user who consumes the point cloud content, and includes information about the user (e.g., head orientation information, viewport information, and the like). In particular, when the point cloud content is content for a service (e.g., self-driving service, etc.) that requires interaction with the user, the feedback information may be provided to the content transmitting side (e.g., the transmission device 10000) and/or the service provider. According to embodiments, the feedback information may be used in the reception device 10004 as well as the transmission device 10000, or may not be provided.
The head orientation information according to embodiments is information about the user's head position, orientation, angle, motion, and the like. The reception device 10004 according to the embodiments may calculate the viewport information based on the head orientation information. The viewport information may be information about a region of a point cloud video that the user is viewing. A viewpoint is a point through which the user is viewing the point cloud video, and may refer to a center point of the viewport region. That is, the viewport is a region centered on the viewpoint, and the size and shape of the region may be determined by a field of view (FOV). Accordingly, the reception device 10004 may extract the viewport information based on a vertical or horizontal FOV supported by the device in addition to the head orientation information. Also, the reception device 10004 performs gaze analysis or the like to check the way the user consumes a point cloud, a region that the user gazes at in the point cloud video, a gaze time, and the like. According to embodiments, the reception device 10004 may transmit feedback information including the result of the gaze analysis to the transmission device 10000. The feedback information according to the embodiments may be acquired in the rendering and/or display process. The feedback information according to the embodiments may be secured by one or more sensors included in the reception device 10004. According to embodiments, the feedback information may be secured by the renderer 10007 or a separate external element (or device, component, or the like). The dotted lines in
According to embodiments, the transmission device 10000 may be called an encoder, a transmission device, a transmitter, or the like, and the reception device 10004 may be called a decoder, a receiving device, a receiver, or the like.
The point cloud data processed in the point cloud content providing system of
The elements of the point cloud content providing system illustrated in
The block diagram of
The point cloud content providing system according to the embodiments (e.g., the point cloud transmission device 10000 or the point cloud video acquirer 10001) may acquire a point cloud video (20000). The point cloud video is represented by a point cloud belonging to a coordinate system for expressing a 3D space. The point cloud video according to the embodiments may include a Ply (Polygon File format or the Stanford Triangle format) file. When the point cloud video has one or more frames, the acquired point cloud video may include one or more Ply files. The Ply files contain point cloud data, such as point geometry and/or attributes. The geometry includes positions of points. The position of each point may be represented by parameters (e.g., values of the X, Y, and Z axes) representing a three-dimensional coordinate system (e.g., a coordinate system composed of X, Y and Z axes). The attributes include attributes of points (e.g., information about texture, color (in YCbCr or RGB), reflectance r, transparency, etc. of each point). A point has one or more attributes. For example, a point may have an attribute that is a color, or two attributes that are color and reflectance. According to embodiments, the geometry may be called positions, geometry information, geometry data, or the like, and the attribute may be called attributes, attribute information, attribute data, or the like. The point cloud content providing system (e.g., the point cloud transmission device 10000 or the point cloud video acquirer 10001) may secure point cloud data from information (e.g., depth information, color information, etc.) related to the acquisition process of the point cloud video.
The point cloud content providing system (e.g., the transmission device 10000 or the point cloud video encoder 10002) according to the embodiments may encode the point cloud data (20001). The point cloud content providing system may encode the point cloud data based on point cloud compression coding. As described above, the point cloud data may include the geometry and attributes of a point. Accordingly, the point cloud content providing system may perform geometry encoding of encoding the geometry and output a geometry bitstream. The point cloud content providing system may perform attribute encoding of encoding attributes and output an attribute bitstream. According to embodiments, the point cloud content providing system may perform the attribute encoding based on the geometry encoding. The geometry bitstream and the attribute bitstream according to the embodiments may be multiplexed and output as one bitstream. The bitstream according to the embodiments may further contain signaling information related to the geometry encoding and attribute encoding.
The point cloud content providing system (e.g., the transmission device 10000 or the transmitter 10003) according to the embodiments may transmit the encoded point cloud data (20002). As illustrated in
The point cloud content providing system (e.g., the reception device 10004 or the receiver 10005) according to the embodiments may receive the bitstream containing the encoded point cloud data. In addition, the point cloud content providing system (e.g., the reception device 10004 or the receiver 10005) may demultiplex the bitstream.
The point cloud content providing system (e.g., the reception device 10004 or the point cloud video decoder 10005) may decode the encoded point cloud data (e.g., the geometry bitstream, the attribute bitstream) transmitted in the bitstream. The point cloud content providing system (e.g., the reception device 10004 or the point cloud video decoder 10005) may decode the point cloud video data based on the signaling information related to encoding of the point cloud video data contained in the bitstream. The point cloud content providing system (e.g., the reception device 10004 or the point cloud video decoder 10005) may decode the geometry bitstream to reconstruct the positions (geometry) of points. The point cloud content providing system may reconstruct the attributes of the points by decoding the attribute bitstream based on the reconstructed geometry. The point cloud content providing system (e.g., the reception device 10004 or the point cloud video decoder 10005) may reconstruct the point cloud video based on the positions according to the reconstructed geometry and the decoded attributes.
The point cloud content providing system according to the embodiments (e.g., the reception device 10004 or the renderer 10007) may render the decoded point cloud data (20004). The point cloud content providing system (e.g., the reception device 10004 or the renderer 10007) may render the geometry and attributes decoded through the decoding process, using various rendering methods. Points in the point cloud content may be rendered to a vertex having a certain thickness, a cube having a specific minimum size centered on the corresponding vertex position, or a circle centered on the corresponding vertex position. All or part of the rendered point cloud content is provided to the user through a display (e.g., a VR/AR display, a general display, etc.).
The point cloud content providing system (e.g., the reception device 10004) according to the embodiments may secure feedback information (20005). The point cloud content providing system may encode and/or decode point cloud data based on the feedback information. The feedback information and the operation of the point cloud content providing system according to the embodiments are the same as the feedback information and the operation described with reference to
Point cloud content includes a point cloud video (images and/or videos) representing an object and/or environment located in various 3D spaces (e.g., a 3D space representing a real environment, a 3D space representing a virtual environment, etc.). Accordingly, the point cloud content providing system according to the embodiments may capture a point cloud video using one or more cameras (e.g., an infrared camera capable of securing depth information, an RGB camera capable of extracting color information corresponding to the depth information, etc.), a projector (e.g., an infrared pattern projector to secure depth information), a LiDAR, or the like. The point cloud content providing system according to the embodiments may extract the shape of geometry composed of points in a 3D space from the depth information and extract the attributes of each point from the color information to secure point cloud data. An image and/or video according to the embodiments may be captured based on at least one of the inward-facing technique and the outward-facing technique.
The left part of
The right part of
As shown in the figure, the point cloud content may be generated based on the capturing operation of one or more cameras. In this case, the coordinate system may differ among the cameras, and accordingly the point cloud content providing system may calibrate one or more cameras to set a global coordinate system before the capturing operation. In addition, the point cloud content providing system may generate point cloud content by synthesizing an arbitrary image and/or video with an image and/or video captured by the above-described capture technique. The point cloud content providing system may not perform the capturing operation described in
The point cloud content providing system may generate one piece of point cloud content by performing coordinate transformation on points of the point cloud video secured from each camera. The point cloud content providing system may perform coordinate transformation on the points based on the coordinates of the position of each camera. Accordingly, the point cloud content providing system may generate content representing one wide range, or may generate point cloud content having a high density of points.
As described with reference to
The point cloud encoder according to the embodiments includes a coordinate transformer (Transform coordinates) 40000, a quantizer (Quantize and remove points (voxelize)) 40001, an octree analyzer (Analyze octree) 40002, and a surface approximation analyzer (Analyze surface approximation) 40003, an arithmetic encoder (Arithmetic encode) 40004, a geometry reconstructor (Reconstruct geometry) 40005, a color transformer (Transform colors) 40006, an attribute transformer (Transform attributes) 40007, a RAHT transformer (RAHT) 40008, an LOD generator (Generate LOD) 40009, a lifting transformer (Lifting) 40010, a coefficient quantizer (Quantize coefficients) 40011, and/or an arithmetic encoder (Arithmetic encode) 40012.
The coordinate transformer 40000, the quantizer 40001, the octree analyzer 40002, the surface approximation analyzer 40003, the arithmetic encoder 40004, and the geometry reconstructor 40005 may perform geometry encoding. The geometry encoding according to the embodiments may include octree geometry coding, predictive tree geometry coding, direct coding, trisoup geometry encoding, and entropy encoding. The direct coding and trisoup geometry encoding are applied selectively or in combination. The geometry encoding is not limited to the above-described example.
As shown in the figure, the coordinate transformer 40000 according to the embodiments receives positions and transforms the same into coordinates. For example, the positions may be transformed into position information in a three-dimensional space (e.g., a three-dimensional space represented by an XYZ coordinate system). The position information in the three-dimensional space according to the embodiments may be referred to as geometry information.
The quantizer 40001 according to the embodiments quantizes the geometry. For example, the quantizer 40001 may quantize the points based on a minimum position value of all points (e.g., a minimum value on each of the X, Y, and Z axes). The quantizer 40001 performs a quantization operation of multiplying the difference between the minimum position value and the position value of each point by a preset quantization scale value and then finding the nearest integer value by rounding the value obtained through the multiplication. Thus, one or more points may have the same quantized position (or position value). The quantizer 40001 according to the embodiments performs voxelization based on the quantized positions to reconstruct quantized points. As in the case of a pixel, which is the minimum unit containing 2D image/video information, points of point cloud content (or 3D point cloud video) according to the embodiments may be included in one or more voxels. The term voxel, which is a compound of volume and pixel, refers to a 3D cubic space generated when a 3D space is divided into units (unit=1.0) based on the axes representing the 3D space (e.g., X-axis, Y-axis, and Z-axis). The quantizer 40001 may match groups of points in the 3D space with voxels. According to embodiments, one voxel may include only one point. According to embodiments, one voxel may include one or more points. In order to express one voxel as one point, the position of the center of a voxel may be set based on the positions of one or more points included in the voxel. In this case, attributes of all positions included in one voxel may be combined and assigned to the voxel.
The octree analyzer 40002 according to the embodiments performs octree geometry coding (or octree coding) to present voxels in an octree structure. The octree structure represents points matched with voxels, based on the octal tree structure.
The surface approximation analyzer 40003 according to the embodiments may analyze and approximate the octree. The octree analysis and approximation according to the embodiments is a process of analyzing a region containing a plurality of points to efficiently provide octree and voxelization.
The arithmetic encoder 40004 according to the embodiments performs entropy encoding on the octree and/or the approximated octree. For example, the encoding scheme includes arithmetic encoding. As a result of the encoding, a geometry bitstream is generated.
The color transformer 40006, the attribute transformer 40007, the RAHT transformer 40008, the LOD generator 40009, the lifting transformer 40010, the coefficient quantizer 40011, and/or the arithmetic encoder 40012 perform attribute encoding. As described above, one point may have one or more attributes. The attribute encoding according to the embodiments is equally applied to the attributes that one point has. However, when an attribute (e.g., color) includes one or more elements, attribute encoding is independently applied to each element. The attribute encoding according to the embodiments includes color transform coding, attribute transform coding, region adaptive hierarchical transform (RAHT) coding, interpolation-based hierarchical nearest-neighbor prediction (prediction transform) coding, and interpolation-based hierarchical nearest-neighbor prediction with an update/lifting step (lifting transform) coding. Depending on the point cloud content, the RAHT coding, the prediction transform coding and the lifting transform coding described above may be selectively used, or a combination of one or more of the coding schemes may be used. The attribute encoding according to the embodiments is not limited to the above-described example.
The color transformer 40006 according to the embodiments performs color transform coding of transforming color values (or textures) included in the attributes. For example, the color transformer 40006 may transform the format of color information (for example, from RGB to YCbCr). The operation of the color transformer 40006 according to embodiments may be optionally applied according to the color values included in the attributes.
The geometry reconstructor 40005 according to the embodiments reconstructs (decompresses) the octree, the predictive tree and/or the approximated octree. The geometry reconstructor 40005 reconstructs the octree/voxels based on the result of analyzing the distribution of points. The reconstructed octree/voxels may be referred to as reconstructed geometry (restored geometry).
The attribute transformer 40007 according to the embodiments performs attribute transformation to transform the attributes based on the reconstructed geometry and/or the positions on which geometry encoding is not performed. As described above, since the attributes are dependent on the geometry, the attribute transformer 40007 may transform the attributes based on the reconstructed geometry information. For example, based on the position value of a point included in a voxel, the attribute transformer 40007 may transform the attribute of the point at the position. As described above, when the position of the center of a voxel is set based on the positions of one or more points included in the voxel, the attribute transformer 40007 transforms the attributes of the one or more points. When the trisoup geometry encoding is performed, the attribute transformer 40007 may transform the attributes based on the trisoup geometry encoding.
The attribute transformer 40007 may perform the attribute transformation by calculating the average of attributes or attribute values of neighboring points (e.g., color or reflectance of each point) within a specific position/radius from the position (or position value) of the center of each voxel. The attribute transformer 40007 may apply a weight according to the distance from the center to each point in calculating the average. Accordingly, each voxel has a position and a calculated attribute (or attribute value).
The attribute transformer 40007 may search for neighboring points existing within a specific position/radius from the position of the center of each voxel based on the K-D tree or the Morton code. The K-D tree is a binary search tree and supports a data structure capable of managing points based on the positions such that nearest neighbor search (NNS) can be performed quickly. The Morton code is generated by presenting coordinates (e.g., (x, y, z)) representing 3D positions of all points as bit values and mixing the bits. For example, when the coordinates representing the position of a point are (5, 9, 1), the bit values for the coordinates are (0101, 1001, 0001). Mixing the bit values according to the bit index in order of z, y, and x yields 010001000111. This value is expressed as a decimal number of 1095. That is, the Morton code value of the point having coordinates (5, 9, 1) is 1095. The attribute transformer 40007 may order the points based on the Morton code values and perform NNS through a depth-first traversal process. After the attribute transformation operation, the K-D tree or the Morton code is used when the NNS is needed in another transformation process for attribute coding.
As shown in the figure, the transformed attributes are input to the RAHT transformer 40008 and/or the LOD generator 40009.
The RAHT transformer 40008 according to the embodiments performs RAHT coding for predicting attribute information based on the reconstructed geometry information. For example, the RAHT transformer 40008 may predict attribute information of a node at a higher level in the octree based on the attribute information associated with a node at a lower level in the octree.
The LOD generator 40009 according to the embodiments generates a level of detail (LOD) to perform prediction transform coding. The LOD according to the embodiments is a degree of detail of point cloud content. As the LOD value decrease, it indicates that the detail of the point cloud content is degraded. As the LOD value increases, it indicates that the detail of the point cloud content is enhanced. Points may be classified by the LOD.
The lifting transformer 40010 according to the embodiments performs lifting transform coding of transforming the attributes a point cloud based on weights. As described above, lifting transform coding may be optionally applied.
The coefficient quantizer 40011 according to the embodiments quantizes the attribute-coded attributes based on coefficients.
The arithmetic encoder 40012 according to the embodiments encodes the quantized attributes based on arithmetic coding.
Although not shown in the figure, the elements of the point cloud encoder of
As described with reference to
The upper part of
As shown in the middle of the upper part of
The lower part of
The point cloud encoder (e.g., the point cloud encoder of
Accordingly, for the above-described specific region (or a node other than the leaf node of the octree), the point cloud encoder according to the embodiments may skip voxelization and perform direct coding to directly code the positions of points included in the specific region. The coordinates of a direct coding point according to the embodiments are referred to as direct coding mode (DCM). The point cloud encoder according to the embodiments may also perform trisoup geometry encoding, which is to reconstruct the positions of the points in the specific region (or node) based on voxels, based on a surface model. The trisoup geometry encoding is geometry encoding that represents an object as a series of triangular meshes. Accordingly, the point cloud decoder may generate a point cloud from the mesh surface. The direct coding and trisoup geometry encoding according to the embodiments may be selectively performed. In addition, the direct coding and trisoup geometry encoding according to the embodiments may be performed in combination with octree geometry coding (or octree coding).
To perform direct coding, the option to use the direct mode for applying direct coding should be activated. A node to which direct coding is to be applied is not a leaf node, and points less than a threshold should be present within a specific node. In addition, the total number of points to which direct coding is to be applied should not exceed a preset threshold. When the conditions above are satisfied, the point cloud encoder (or the arithmetic encoder 40004) according to the embodiments may perform entropy coding on the positions (or position values) of the points.
The point cloud encoder (e.g., the surface approximation analyzer 40003) according to the embodiments may determine a specific level of the octree (a level less than the depth d of the octree), and the surface model may be used staring with that level to perform trisoup geometry encoding to reconstruct the positions of points in the region of the node based on voxels (Trisoup mode). The point cloud encoder according to the embodiments may specify a level at which trisoup geometry encoding is to be applied. For example, when the specific level is equal to the depth of the octree, the point cloud encoder does not operate in the trisoup mode. In other words, the point cloud encoder according to the embodiments may operate in the trisoup mode only when the specified level is less than the value of depth of the octree. The 3D cube region of the nodes at the specified level according to the embodiments is called a block. One block may include one or more voxels. The block or voxel may correspond to a brick. Geometry is represented as a surface within each block. The surface according to embodiments may intersect with each edge of a block at most once.
One block has 12 edges, and accordingly there are at least 12 intersections in one block. Each intersection is called a vertex (or apex). A vertex present along an edge is detected when there is at least one occupied voxel adjacent to the edge among all blocks sharing the edge. The occupied voxel according to the embodiments refers to a voxel containing a point. The position of the vertex detected along the edge is the average position along the edge of all voxels adjacent to the edge among all blocks sharing the edge.
Once the vertex is detected, the point cloud encoder according to the embodiments may perform entropy encoding on the starting point (x, y, z) of the edge, the direction vector (Δx, Δy, Δz) of the edge, and the vertex position value (relative position value within the edge). When the trisoup geometry encoding is applied, the point cloud encoder according to the embodiments (e.g., the geometry reconstructor 40005) may generate restored geometry (reconstructed geometry) by performing the triangle reconstruction, up-sampling, and voxelization processes.
The vertices positioned at the edge of the block determine a surface that passes through the block. The surface according to the embodiments is a non-planar polygon. In the triangle reconstruction process, a surface represented by a triangle is reconstructed based on the starting point of the edge, the direction vector of the edge, and the position values of the vertices. The triangle reconstruction process is performed by: i) calculating the centroid value of each vertex, ii) subtracting the center value from each vertex value, and iii) estimating the sum of the squares of the values obtained by the subtraction.
The minimum value of the sum is estimated, and the projection process is performed according to the axis with the minimum value. For example, when the element x is the minimum, each vertex is projected on the x-axis with respect to the center of the block, and projected on the (y, z) plane. When the values obtained through projection on the (y, z) plane are (ai, bi), the value of θ is estimated through a tan 2(bi, ai), and the vertices are ordered based on the value of 0. The table below shows a combination of vertices for creating a triangle according to the number of the vertices. The vertices are ordered from 1 to n. The table below shows that for four vertices, two triangles may be constructed according to combinations of vertices. The first triangle may consist of vertices 1, 2, and 3 among the ordered vertices, and the second triangle may consist of vertices 3, 4, and 1 among the ordered vertices.
The upsampling process is performed to add points in the middle along the edge of the triangle and perform voxelization. The added points are generated based on the upsampling factor and the width of the block. The added points are called refined vertices. The point cloud encoder according to the embodiments may voxelize the refined vertices. In addition, the point cloud encoder may perform attribute encoding based on the voxelized positions (or position values).
In order to increase the compression efficiency of the point cloud video, the point cloud encoder according to the embodiments may perform entropy coding based on context adaptive arithmetic coding.
As described with reference to
The lower part of
As described with reference to
The point cloud encoder (e.g., the LOD generator 40009) may classify (or reorganize) points by LOD. The figure shows the point cloud content corresponding to LODs. The leftmost picture in the figure represents original point cloud content. The second picture from the left of the figure represents distribution of the points in the lowest LOD, and the rightmost picture in the figure represents distribution of the points in the highest LOD. That is, the points in the lowest LOD are sparsely distributed, and the points in the highest LOD are densely distributed. That is, as the LOD rises in the direction pointed by the arrow indicated at the bottom of the figure, the space (or distance) between points is narrowed.
As described with reference to
The upper part of
As described with reference to
The point cloud encoder according to the embodiments may generate a predictor for points to perform prediction transform coding for setting a predicted attribute (or predicted attribute value) of each point. That is, N predictors may be generated for N points. The predictor according to the embodiments may calculate a weight (=1/distance) based on the LOD value of each point, indexing information about neighboring points present within a set distance for each LOD, and a distance to the neighboring points.
The predicted attribute (or attribute value) according to the embodiments is set to the average of values obtained by multiplying the attributes (or attribute values) (e.g., color, reflectance, etc.) of neighbor points set in the predictor of each point by a weight (or weight value) calculated based on the distance to each neighbor point. The point cloud encoder according to the embodiments (e.g., the coefficient quantizer 40011) may quantize and inversely quantize the residuals (which may be called residual attributes, residual attribute values, attribute residual value or attribute prediction residuals) obtained by subtracting a predicted attribute (attribute value) from the attribute (attribute value) of each point. The quantization process is configured as shown in the following table.
When the predictor of each point has neighbor points, the point cloud encoder (e.g., the arithmetic encoder 40012) according to the embodiments may perform entropy coding on the quantized and inversely quantized residual values as described above. When the predictor of each point has no neighbor point, the point cloud encoder according to the embodiments (e.g., the arithmetic encoder 40012) may perform entropy coding on the attributes of the corresponding point without performing the above-described operation.
The point cloud encoder according to the embodiments (e.g., the lifting transformer 40010) may generate a predictor of each point, set the calculated LOD and register neighbor points in the predictor, and set weights according to the distances to neighbor points to perform lifting transform coding. The lifting transform coding according to the embodiments is similar to the above-described prediction transform coding, but differs therefrom in that weights are cumulatively applied to attribute values. The process of cumulatively applying weights to the attribute values according to embodiments is configured as follows.
The point cloud encoder (e.g., the RAHT transformer 40008) according to the embodiments may perform RAHT transform coding in which attributes of nodes of a higher level are predicted using the attributes associated with nodes of a lower level in the octree. RAHT transform coding is an example of attribute intra coding through an octree backward scan. The point cloud encoder according to the embodiments scans the entire region from the voxel and repeats the merging process of merging the voxels into a larger block at each step until the root node is reached. The merging process according to the embodiments is performed only on the occupied nodes. The merging process is not performed on the empty node. The merging process is performed on an upper node immediately above the empty node.
The equation below represents a RAHT transformation matrix. In the equation, gl
Here, gl−1
The value of gDC is also quantized and subjected to entropy coding like the high-pass coefficients.
The point cloud decoder illustrated in
The point cloud decoder illustrated in
As described with reference to
The point cloud decoder according to the embodiments includes an arithmetic decoder (Arithmetic decode) 11000, an octree synthesizer (Synthesize octree) 11001, a surface approximation synthesizer (Synthesize surface approximation) 11002, and a geometry reconstructor (Reconstruct geometry) 11003, a coordinate inverse transformer (Inverse transform coordinates) 11004, an arithmetic decoder (Arithmetic decode) 11005, an inverse quantizer (Inverse quantize) 11006, a RAHT transformer 11007, an LOD generator (Generate LOD) 11008, an inverse lifter (inverse lifting) 11009, and/or a color inverse transformer (Inverse transform colors) 11010.
The arithmetic decoder 11000, the octree synthesizer 11001, the surface approximation synthesizer 11002, and the geometry reconstructor 11003, and the coordinate inverse transformer 11004 may perform geometry decoding. The geometry decoding according to the embodiments may include direct coding and trisoup geometry decoding. The direct coding and trisoup geometry decoding are selectively applied. The geometry decoding is not limited to the above-described example, and is performed as a reverse process of the geometry encoding described with reference to
The arithmetic decoder 11000 according to the embodiments decodes the received geometry bitstream based on the arithmetic coding. The operation of the arithmetic decoder 11000 corresponds to the reverse process of the arithmetic encoder 40004.
The octree synthesizer 11001 according to the embodiments may generate an octree by acquiring an occupancy code from the decoded geometry bitstream (or information on the geometry secured as a result of decoding). The occupancy code is configured as described in detail with reference to
When the trisoup geometry encoding is applied, the surface approximation synthesizer 11002 according to the embodiments may synthesize a surface based on the decoded geometry and/or the generated octree.
The geometry reconstructor 11003 according to the embodiments may regenerate geometry based on the surface and/or the decoded geometry. As described with reference to
The coordinate inverse transformer 11004 according to the embodiments may acquire positions of the points by transforming the coordinates based on the reconstructed geometry.
The arithmetic decoder 11005, the inverse quantizer 11006, the RAHT transformer 11007, the LOD generator 11008, the inverse lifter 11009, and/or the color inverse transformer 11010 may perform the attribute decoding described with reference to
The arithmetic decoder 11005 according to the embodiments decodes the attribute bitstream by arithmetic coding.
The inverse quantizer 11006 according to the embodiments inversely quantizes the information about the decoded attribute bitstream or attributes secured as a result of the decoding, and outputs the inversely quantized attributes (or attribute values). The inverse quantization may be selectively applied based on the attribute encoding of the point cloud encoder.
According to embodiments, the RAHT transformer 11007, the LOD generator 11008, and/or the inverse lifter 11009 may process the reconstructed geometry and the inversely quantized attributes. As described above, the RAHT transformer 11007, the LOD generator 11008, and/or the inverse lifter 11009 may selectively perform a decoding operation corresponding to the encoding of the point cloud encoder.
The color inverse transformer 11010 according to the embodiments performs inverse transform coding to inversely transform a color value (or texture) included in the decoded attributes. The operation of the color inverse transformer 11010 may be selectively performed based on the operation of the color transformer 40006 of the point cloud encoder.
Although not shown in the figure, the elements of the point cloud decoder of
The transmission device shown in
The data input unit 12000 according to the embodiments receives or acquires point cloud data. The data input unit 12000 may perform an operation and/or acquisition method the same as or similar to the operation and/or acquisition method of the point cloud video acquirer 10001 (or the acquisition process 20000 described with reference to
The data input unit 12000, the quantization processor 12001, the voxelization processor 12002, the octree occupancy code generator 12003, the surface model processor 12004, the intra/inter-coding processor 12005, and the arithmetic coder 12006 perform geometry encoding. The geometry encoding according to the embodiments is the same as or similar to the geometry encoding described with reference to
The quantization processor 12001 according to the embodiments quantizes geometry (e.g., position values of points). The operation and/or quantization of the quantization processor 12001 is the same as or similar to the operation and/or quantization of the quantizer 40001 described with reference to
The voxelization processor 12002 according to the embodiments voxelizes the quantized position values of the points. The voxelization processor 12002 may perform an operation and/or process the same or similar to the operation and/or the voxelization process of the quantizer 40001 described with reference to
The octree occupancy code generator 12003 according to the embodiments performs octree coding on the voxelized positions of the points based on an octree structure. The octree occupancy code generator 12003 may generate an occupancy code. The octree occupancy code generator 12003 may perform an operation and/or method the same as or similar to the operation and/or method of the point cloud encoder (or the octree analyzer 40002) described with reference to
The surface model processor 12004 according to the embodiments may perform trisoup geometry encoding based on a surface model to reconstruct the positions of points in a specific region (or node) on a voxel basis. The surface model processor 12004 may perform an operation and/or method the same as or similar to the operation and/or method of the point cloud encoder (e.g., the surface approximation analyzer 40003) described with reference to
The intra/inter-coding processor 12005 according to the embodiments may perform intra/inter-coding on point cloud data. The intra/inter-coding processor 12005 may perform coding the same as or similar to the intra/inter-coding described with reference to
The arithmetic coder 12006 according to the embodiments performs entropy encoding on an octree of the point cloud data and/or an approximated octree. For example, the encoding scheme includes arithmetic encoding. The arithmetic coder 12006 performs an operation and/or method the same as or similar to the operation and/or method of the arithmetic encoder 40004.
The metadata processor 12007 according to the embodiments processes metadata about the point cloud data, for example, a set value, and provides the same to a necessary processing process such as geometry encoding and/or attribute encoding. Also, the metadata processor 12007 according to the embodiments may generate and/or process signaling information related to the geometry encoding and/or the attribute encoding. The signaling information according to the embodiments may be encoded separately from the geometry encoding and/or the attribute encoding. The signaling information according to the embodiments may be interleaved.
The color transform processor 12008, the attribute transform processor 12009, the prediction/lifting/RAHT transform processor 12010, and the arithmetic coder 12011 perform the attribute encoding. The attribute encoding according to the embodiments is the same as or similar to the attribute encoding described with reference to
The color transform processor 12008 according to the embodiments performs color transform coding to transform color values included in attributes. The color transform processor 12008 may perform color transform coding based on the reconstructed geometry. The reconstructed geometry is the same as described with reference to
The attribute transform processor 12009 according to the embodiments performs attribute transformation to transform the attributes based on the reconstructed geometry and/or the positions on which geometry encoding is not performed. The attribute transform processor 12009 performs an operation and/or method the same as or similar to the operation and/or method of the attribute transformer 40007 described with reference to
The arithmetic coder 12011 according to the embodiments may encode the coded attributes based on the arithmetic coding. The arithmetic coder 12011 performs an operation and/or method the same as or similar to the operation and/or method of the arithmetic encoder 400012.
The transmission processor 12012 according to the embodiments may transmit each bitstream containing encoded geometry and/or encoded attributes and metadata information, or transmit one bitstream configured with the encoded geometry and/or the encoded attributes and the metadata information. When the encoded geometry and/or the encoded attributes and the metadata information according to the embodiments are configured into one bitstream, the bitstream may include one or more sub-bitstreams. The bitstream according to the embodiments may contain signaling information including a sequence parameter set (SPS) for signaling of a sequence level, a geometry parameter set (GPS) for signaling of geometry information coding, an attribute parameter set (APS) for signaling of attribute information coding, and a tile parameter set (TPS) for signaling of a tile level, and slice data. The slice data may include information about one or more slices. One slice according to embodiments may include one geometry bitstream Geom00 and one or more attribute bitstreams Attr00 and Attr10.
A slice refers to a series of syntax elements representing the entirety or part of a coded point cloud frame.
The TPS according to the embodiments may include information about each tile (e.g., coordinate information and height/size information about a bounding box) for one or more tiles. The geometry bitstream may contain a header and a payload. The header of the geometry bitstream according to the embodiments may contain a parameter set identifier (geom_parameter_set_id), a tile identifier (geom_tile_id) and a slice identifier (geom_slice_id) included in the GPS, and information about the data contained in the payload. As described above, the metadata processor 12007 according to the embodiments may generate and/or process the signaling information and transmit the same to the transmission processor 12012. According to embodiments, the elements to perform geometry encoding and the elements to perform attribute encoding may share data/information with each other as indicated by dotted lines. The transmission processor 12012 according to the embodiments may perform an operation and/or transmission method the same as or similar to the operation and/or transmission method of the transmitter 10003. Details are the same as those described with reference to
The reception device illustrated in
The reception device according to the embodiment may include a receiver 13000, a reception processor 13001, an arithmetic decoder 13002, an occupancy code-based octree reconstruction processor 13003, a surface model processor (triangle reconstruction, up-sampling, voxelization) 13004, an inverse quantization processor 13005, a metadata parser 13006, an arithmetic decoder 13007, an inverse quantization processor 13008, a prediction/lifting/RAHT inverse transform processor 13009, a color inverse transform processor 13010, and/or a renderer 13011. Each element for decoding according to the embodiments may perform a reverse process of the operation of a corresponding element for encoding according to the embodiments.
The receiver 13000 according to the embodiments receives point cloud data. The receiver 13000 may perform an operation and/or reception method the same as or similar to the operation and/or reception method of the receiver 10005 of
The reception processor 13001 according to the embodiments may acquire a geometry bitstream and/or an attribute bitstream from the received data. The reception processor 13001 may be included in the receiver 13000.
The arithmetic decoder 13002, the occupancy code-based octree reconstruction processor 13003, the surface model processor 13004, and the inverse quantization processor 13005 may perform geometry decoding. The geometry decoding according to embodiments is the same as or similar to the geometry decoding described with reference to
The arithmetic decoder 13002 according to the embodiments may decode the geometry bitstream based on arithmetic coding. The arithmetic decoder 13002 performs an operation and/or coding the same as or similar to the operation and/or coding of the arithmetic decoder 11000.
The occupancy code-based octree reconstruction processor 13003 according to the embodiments may reconstruct an octree by acquiring an occupancy code from the decoded geometry bitstream (or information about the geometry secured as a result of decoding). The occupancy code-based octree reconstruction processor 13003 performs an operation and/or method the same as or similar to the operation and/or octree generation method of the octree synthesizer 11001. When the trisoup geometry encoding is applied, the surface model processor 13004 according to the embodiments may perform trisoup geometry decoding and related geometry reconstruction (e.g., triangle reconstruction, up-sampling, voxelization) based on the surface model method. The surface model processor 13004 performs an operation the same as or similar to that of the surface approximation synthesizer 11002 and/or the geometry reconstructor 11003.
The inverse quantization processor 13005 according to the embodiments may inversely quantize the decoded geometry.
The metadata parser 13006 according to the embodiments may parse metadata contained in the received point cloud data, for example, a set value. The metadata parser 13006 may pass the metadata to geometry decoding and/or attribute decoding. The metadata is the same as that described with reference to
The arithmetic decoder 13007, the inverse quantization processor 13008, the prediction/lifting/RAHT inverse transform processor 13009 and the color inverse transform processor 13010 perform attribute decoding. The attribute decoding is the same as or similar to the attribute decoding described with reference to
The arithmetic decoder 13007 according to the embodiments may decode the attribute bitstream by arithmetic coding. The arithmetic decoder 13007 may decode the attribute bitstream based on the reconstructed geometry. The arithmetic decoder 13007 performs an operation and/or coding the same as or similar to the operation and/or coding of the arithmetic decoder 11005.
The inverse quantization processor 13008 according to the embodiments may inversely quantize the decoded attribute bitstream. The inverse quantization processor 13008 performs an operation and/or method the same as or similar to the operation and/or inverse quantization method of the inverse quantizer 11006.
The prediction/lifting/RAHT inverse transform processor 13009 according to the embodiments may process the reconstructed geometry and the inversely quantized attributes. The prediction/lifting/RAHT inverse transform processor 13009 performs one or more of operations and/or decoding the same as or similar to the operations and/or decoding of the RAHT transformer 11007, the LOD generator 11008, and/or the inverse lifter 11009. The color inverse transform processor 13010 according to the embodiments performs inverse transform coding to inversely transform color values (or textures) included in the decoded attributes. The color inverse transform processor 13010 performs an operation and/or inverse transform coding the same as or similar to the operation and/or inverse transform coding of the color inverse transformer 11010. The renderer 13011 according to the embodiments may render the point cloud data.
The structure of
The cloud network 1400 may represent a network that constitutes part of the cloud computing infrastructure or is present in the cloud computing infrastructure. Here, the cloud network 1400 may be configured using a 3G network, 4G or Long Term Evolution (LTE) network, or a 5G network.
The server 1460 may be connected to at least one of the robot 1410, the self-driving vehicle 1420, the XR device 1430, the smartphone 1440, the home appliance 1450, and/or the HMD 1470 over the cloud network 1400 and may assist in at least a part of the processing of the connected devices 1410 to 1470.
The HMD 1470 represents one of the implementation types of the XR device and/or the PCC device according to the embodiments. The HMD type device according to the embodiments includes a communication unit, a control unit, a memory, an I/O unit, a sensor unit, and a power supply unit.
Hereinafter, various embodiments of the devices 1410 to 1450 to which the above-described technology is applied will be described. The devices 1410 to 1450 illustrated in
The XR/PCC device 1430 may employ PCC technology and/or XR (AR+VR) technology, and may be implemented as an HMD, a head-up display (HUD) provided in a vehicle, a television, a mobile phone, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a stationary robot, or a mobile robot.
The XR/PCC device 1430 may analyze 3D point cloud data or image data acquired through various sensors or from an external device and generate position data and attribute data about 3D points. Thereby, the XR/PCC device 1430 may acquire information about the surrounding space or a real object, and render and output an XR object. For example, the XR/PCC device 1430 may match an XR object including auxiliary information about a recognized object with the recognized object and output the matched XR object.
The XR/PCC device 1430 may be implemented as a mobile phone 1440 by applying PCC technology.
The mobile phone 1440 may decode and display point cloud content based on the PCC technology.
The self-driving vehicle 1420 may be implemented as a mobile robot, a vehicle, an unmanned aerial vehicle, or the like by applying the PCC technology and the XR technology.
The self-driving vehicle 1420 to which the XR/PCC technology is applied may represent a self-driving vehicle provided with means for providing an XR image, or a self-driving vehicle that is a target of control/interaction in the XR image. In particular, the self-driving vehicle 1420 which is a target of control/interaction in the XR image may be distinguished from the XR device 1430 and may be operatively connected thereto.
The self-driving vehicle 1420 having means for providing an XR/PCC image may acquire sensor information from sensors including a camera, and output the generated XR/PCC image based on the acquired sensor information. For example, the self-driving vehicle 1420 may have an HUD and output an XR/PCC image thereto, thereby providing an occupant with an XR/PCC object corresponding to a real object or an object present on the screen.
When the XR/PCC object is output to the HUD, at least a part of the XR/PCC object may be output to overlap the real object to which the occupant's eyes are directed. On the other hand, when the XR/PCC object is output on a display provided inside the self-driving vehicle, at least a part of the XR/PCC object may be output to overlap an object on the screen. For example, the self-driving vehicle 1220 may output XR/PCC objects corresponding to objects such as a road, another vehicle, a traffic light, a traffic sign, a two-wheeled vehicle, a pedestrian, and a building.
The virtual reality (VR) technology, the augmented reality (AR) technology, the mixed reality (MR) technology and/or the point cloud compression (PCC) technology according to the embodiments are applicable to various devices.
In other words, the VR technology is a display technology that provides only CG images of real-world objects, backgrounds, and the like. On the other hand, the AR technology refers to a technology that shows a virtually created CG image on the image of a real object. The MR technology is similar to the AR technology described above in that virtual objects to be shown are mixed and combined with the real world. However, the MR technology differs from the AR technology in that the AR technology makes a clear distinction between a real object and a virtual object created as a CG image and uses virtual objects as complementary objects for real objects, whereas the MR technology treats virtual objects as objects having equivalent characteristics as real objects. More specifically, an example of MR technology applications is a hologram service.
Recently, the VR, AR, and MR technologies are sometimes referred to as extended reality (XR) technology rather than being clearly distinguished from each other. Accordingly, embodiments of the present disclosure are applicable to any of the VR, AR, MR, and XR technologies. The encoding/decoding based on PCC, V-PCC, and G-PCC techniques is applicable to such technologies.
The PCC method/device according to the embodiments may be applied to a vehicle that provides a self-driving service.
A vehicle that provides the self-driving service is connected to a PCC device for wired/wireless communication.
When the point cloud data (PCC) transmission/reception device according to the embodiments is connected to a vehicle for wired/wireless communication, the device may receive/process content data related to an AR/VR/PCC service, which may be provided together with the self-driving service, and transmit the same to the vehicle. In the case where the PCC transmission/reception device is mounted on a vehicle, the PCC transmission/reception device may receive/process content data related to the AR/VR/PCC service according to a user input signal input through a user interface device and provide the same to the user. The vehicle or the user interface device according to the embodiments may receive a user input signal. The user input signal according to the embodiments may include a signal indicating the self-driving service.
As described with reference to
In addition, the attribute information may be a vector of values acquired by one or more sensors, such as the color (RGB, YUV, etc.), reflectance, normal vectors, transparency, brightness, temperature, and the like of a point. The attribute information may be expressed in the form of a scalar or vector.
According to embodiments, the point cloud data may be classified into category 1 of static point cloud data, category 2 of dynamic point cloud data, and category 3, which is acquired through dynamic movement, according to the type of the point cloud data and acquisition method therefor. Category 1 is composed of a point cloud of a single frame with a high density of points for an object or space. The data of category 3 may be divided into frame-based data having multiple frames acquired through movement and fused data of a single frame acquired by matching a point cloud acquired through a LiDAR sensor and a color image acquired as a 2D image for a large space. In addition, for data in Category 1, the color may constitute attribute information. For data in Category 3, the color, reflectance, and color+reflectance values may constitute attribute information according to the characteristics of the content.
The generation of LODs and search for neighbor points according to the embodiments may be performed by a point cloud data transmission/reception device (the transmission device or reception device of
In decoding the point cloud data, the reception device according to embodiments receives an encoded geometry information (geometry) bitstream and attribute information bitstream, decodes the geometry information, and then decodes the attribute information based on the reconstructed geometry information.
In the encoding/decoding process of the transmission/reception device according to embodiments, the prediction transformation and the lifting transformation (prediction inverse transformation and lifting inverse transformation) may divide and group points based on LODs. LODs may be divided into levels based on subsampling. For example, some of the points belonging to a specific LOD may be sampled (or subsampled) to configure points belonging to another LOD. Here, the subsampling may include distance based subsampling, decimation based subsampling, and octree based (or block based) subsampling.
The distance based subsampling is a method of sampling based on the distance between points. For example, points that are farther away than a minimum distance from a specific point are sampled.
The decimation based subsampling is a method of sampling one or more points out of a specific number of points.
The octree based subsampling is a method of sampling one or more points at a specific node based on the node (or block) of the octree corresponding to the LOD.
As such, in the LOD generation process of the transmission/reception device according to embodiments, points may be divided and grouped by subsampling. A group of points belonging to an LOD may be referred to as an LODI, where I denotes the level of the LOD and is an integer starting from 0. LOD0 is the set with the largest distance between points. As I increases, the distance between points in the LOD decreases.
An LOD may include N levels, and the points in each level may be sorted into a one-dimensional array based on Morton order. The sorting of the points (or the space search) may be based on a Morton curve, a Hilbert curve, a Peano curve, or a Gray curve.
The method of neighbor point search of the transmission/reception device according to embodiments may be differentiated between a case of one LOD and a case of N LODs.
In this case, the weight of each neighbor point may be normalized based on the total sum of the weights of its closest neighbor points to apply a weight based on the distance between the points and the current point. For example, when the current point p0 has three neighbors p1, p2, and p3, the weight of each neighbor point may be calculated as 1/|p1−p0|, 1/|p2−p0|, 1/|p3−p0|. The transmission and reception devices may divide the weight of each neighbor point by the total sum of the calculated weights, and predict geometry information or attribute information based on the neighbor points for the current point.
More specifically, in
Referring to
Specifically, referring to
According to the neighbor point search process according to the embodiments described with reference to
In this way, a point that is at a close distance to the current point, but has a large index difference from the current point in the order in which the points are sorted may not be searched for as a neighbor, which may reduce the accuracy of the neighbor search. Points with this characteristic may be referred to as jumping points. The criteria for a jumping point may vary depending on the search range for neighbor points and the Euclidean distance from the current point.
The point cloud data transmission/reception device (transmission/reception device of
The point cloud data transmission/reception device according to embodiments uses a neighborhood node table that includes information about jumping points in relation to a three-dimensional (or N-dimensional) space. Further, the point cloud data transmission/reception device according to embodiments may reference the neighbor node table based on indexes according to a specific point sorting method. In addition, the point cloud data transmission/reception device according to embodiments may use various space search schemes or point sorting methods to search for neighbor points in addition to the sorting method based on the Morton code index.
The Morton code index-based sorting method provides a method to search for nearest neighbor points in a one-dimensional array. However, in three-dimensional space, distance does not accurately reflect close positions and thus additional information is required.
The point cloud data transmission/reception device according to embodiments may use a neighbor node table (which may be referred to as a look up table (LUT)) to search for neighbor points in a 3×3×3 space or larger. Also, neighbor points may be searched for based on an index according to a specific sorting method (e.g., Morton order). In this case, the information contained in the neighbor node table may extend to an N-dimensional space, and the sorting method for the points may include a sorting method based on a Hilbert curve, a Peano curve, or a Gray curve.
In searching for a neighbor point based on a one-dimensional Morton sequence index, a jumping point cannot be considered as a neighbor point, and therefore a neighbor node table may be used. Referring to
When a point is outside the search range in terms of the Morton code index, but close in Euclidean distance to the current point, the point cloud data transmission/reception device according to embodiments may reference the neighbor node table to determine that the point is a neighbor point. In addition, the neighbor node table may be referenced based on the Morton code index, and various other space searches (point sorting methods) may be applied to search for neighbor points.
An example of a one-dimensional array of a neighbor node table is shown below.
This array contains sequence indexes for finding a jumping point 17004 that is a neighbor of the current point 17002 when searching for a neighbor point. The values of the indexes in the neighbor node table (NeighOffset) list the indexes of all points within a distance of +1 or −1 along the x, y, and z axes when the current point 17002 has an index of 7 (NeighOffset[0]=7) (NeighOffset[1] to NeighOffset[26]).
Thus, when searching for a neighbor point, the transmission/reception device according to embodiments may reference the neighbor node table (NeighOffset) for the index value of a jumping point outside the search range. Also, only the index values contained in the neighbor node table (NeighOffset) may be used for neighbor point search. The 26 indexes in the neighbor node table represent 26 points that are adjacent to (or neighboring) each other.
In the neighbor point search according to embodiments, a neighbor point that may be used to predict the current point may be referred to as a predictor. Also, in the neighbor point search according to embodiments, a point may be referred to as a block. In the neighbor point search according to embodiments, blocks that are within an availability window among the blocks adjacent to the block containing the current point may be searched. The availability window according to the embodiments may be referred to as a search range. The availability window may have a volume of an 128×128×128 block. Within the searched block, the points may be searched in order of indexes sorted by LOD level.
In the block search according to embodiments, the blocks may be searched according to the search order and coordinate information about the blocks. The search order and coordinate information about the blocks may be information contained in a table represented by rows or columns.
The neighbor node table according to the embodiments may be expanded to cover a wider range of space. The neighbor node table according to the embodiments may provide a method of neighbor point search based on the relative position and size of the space in which the current point is positioned. The neighbor node table according to the embodiments may contain index information about jumping points for a 3×3×3 space, a 4×4×4 space, or a larger space. The neighbor node table according to the embodiments may include rows and columns, wherein each of the rows may contain index information about points that neighbor each other. That is, points represented by indexes contained in the same row may be points that neighbor each other. Some of the indexes in the same row in the neighbor node table may represent jump points for the current point.
Here is an example of a neighbor node table (or look up table) for points sorted based on the Morton code in a 4×4×4 space.
The neighbor node table above is an array of 8 rows and 27 columns.
The rows of the neighbor node table (NeighOffset_ext) may contain in the first column an index (e.g., an index that is a multiple of 7 in 4×4×4 space) to the point at which a jumping point occurs when the points are sorted in a specific sorting order (e.g., Morton order). The presence of a jumping point indicates that, when the current point is at the corresponding position, there is a point that is within a specific Euclidean distance from the current point, but outside a specific search range in terms of index.
The number of rows in the neighbor node table may be the number of indexes representing points where the jumping point happens in an N×N×N space (e.g., 4×4×4 space). The number of columns in the neighbor node table is the total number of neighboring points for the points contained in a row. The neighboring points may include jumping points.
Referring to
The indexes contained in the rows or columns of the neighbor node table according to the embodiments may be equally applied by the transmission/reception device according to the embodiments, regardless of the order in which they are listed in the neighbor node table.
The neighbor node table according to the embodiments is for a 4×4×4 space. Referring to
When the index of the current point is 35 when the transmission/reception device searches for neighbor points according to embodiments, index 60 may correspond to a jumping point that is not within the neighbor point search range (e.g., 10 points) based on index 35, but whose position is close to index 35. The transmission/reception device according to embodiments may search for the point represented by the sequence index 60 in the neighbor node table as a neighbor point.
As shown in
In other words, the index at which the jumping point occurs and the indexes of the 26 neighbor points may be presented in 26 columns. In an N×N×N space expanded from the 4×4×4 space, the number of rows and columns in the neighbor node table and the values contained in the rows and columns may change. Accordingly, the indexes representing neighbor points may change. The neighbor node table for an N×N×N space may contain the index values representing the jumping points using an N-dimensional array of NeighOffset_ext[i][j][k].
The transmission/reception device according to embodiments may search for neighbors of the current point based on the neighbor node table (NeighOffset_ext) as follows.
In the case of points sorted in Morton order in a 4×4×4 space, when the Morton code index MC_idx of the current point is 138, the Morton code index 138 is divided by 64 (based on the 4×4×4 space). The quotient is 2 and the remainder is 10. Then, the transmission/reception device according to the embodiments may reference a row of the neighbor node table based on the calculated quotient and present the index of the current point in the 4×4×4 space where the current point is positioned based on the calculated remainder. Thus, in the example above, row 2 of the neighbor node table may be referenced to determine whether row 2 contains the sequence index 10. When the second row contains the sequence index 10, all the indexes in row 2 may represent points that are neighbors of the current point.
Referring to the neighbor node table above, row 2 ({21, 17, 7, 20, . . . , 10, 2}) of the neighbor node table contains index 10 in column 25. Therefore, the 26 indexes in row 2, excluding index 10, may represent neighbor points for the current point. The first index 21 in row 2 of the neighbor node table may be construed as a point with a Morton code index of 149 because 64(4×4×4)×2(quotient)+21(index)=149. Therefore, the point with Morton code index 149 is searched as a neighbor of the current point (Morton code index 138). The second index in row 2 of the neighbor node table, 17, may be construed as a point with a Morton code index of 145, because 64 (4×4×4)×2 (quotient)+17 (index)=145. Therefore, the point with Morton code index 145 may be searched as a neighbor of the current point (Morton code index 138). In the same way, other indexes (except index 10) in row 2 of the neighbor node table may be converted to Morton code indexes and searched as neighbor points.
The N-dimensional array of the neighbor node table according to embodiments may be a predefined matrix table (or look up table). Further, the transmission/reception device according to embodiments may calculate i, j, and k of the neighbor node table from an index based on a specific sorting method (e.g., Morton order-based index).
Based on an N×N×N space, i may denote a row in the neighbor node table and j may denote an index.
MC_idx: Morton index
When index j is present in row i of the neighbor node table, the transmission/reception device according to embodiments may search for points included in row i of the neighbor node table as neighbor points. When index j is not present in row i of the neighbor node table, the transmission/reception device according to embodiments may search for points within a search range based on the current point in the order of sorting of the points as neighbor points.
The Morton code indexes may be sorted into values from 0 to 2{circumflex over ( )}3n (where n is a bitdepth). The transmission/reception device according to embodiments may search for neighbor points in a specific backward and forward search range (e.g., a range of 128 indexes) based on the index of the current point. The closer the position of the sorted point is to the position of the current point, the more likely it is that that point has similar attribute information to the current point is searched as a neighbor. When there is a similar point at a close distance, the distance is below a threshold, and thus redundant searches are excluded, thereby reducing the decoding time.
In order to search for points that are close in Euclidean distance but far away in Morton index order, the Morton index for the index of the current point may be modified by an equation. Referring to
The transmission/reception device according to embodiments may search for jumping points first by reprioritizing the jumping points using a formula for neighbor point search. In this case, the formula may be MC_jump={(ex. 7, 14, 21, 28, 35, 42, 49, 56 . . . )}, a set of indexes at which the jumping point occurs, and a set of neighbor points (E_dist_NN) with close Euclidean distance but distant Morton code indexes may be defined. E_dist_NN of specific Indexes may be searched using the MC_jump set as follows.
Points neighboring the current point in a 4×4×4 space or larger may be found through a calculation based on the Morton code index, and neighbor points (points at a distance of 1 to 13) in an N×N×N space may be searched for based on the current point by the following equation.
When the current index/8{circumflex over ( )}(n+1) % α=0, (current index/8{circumflex over ( )}n+α)*β
When current index/8{circumflex over ( )}(n+1) % α is not 0, use a look up table or an index equation based on another space search
Index equation based on another space search
The Morton code index may be calculated by bit-interleaving the three-dimensional point cloud data. The transmission/reception device according to embodiments may search for a jumping point for the current point as a neighbor point by calculation using the neighbor node table (or look up table) and the Morton code index according to embodiments.
Other space search methods may be applied to find points that are close in Euclidean distance to the current point in three-dimensional space. The transmission/reception device according to embodiments may use a Hilbert curve as a point sorting method for neighbor search. The Hilbert curve is characterized by presence within a distance of +1 or −1 with no jumping from the current point. Experiments have shown that high compression efficiency is achieved for high rate attribute information neighbor search and high compression efficiency is achieved for attribute predicting transform. In addition, the transmission/reception device according to embodiments may use various space search algorithms capable of searching in N dimensions, such as the Peano curve and the Gray curve, as a point sorting method for neighbor search.
The attribute information encoder 19000 may generate an attribute information bitstream based on the reconstructed geometry information. The generated geometry information bitstream and attribute information bitstream may be compressed into a bitstream and transmitted to the attribute information decoder 19010. The compressed bitstream may contain signaling information related to the geometry information bitstream and the attribute information bitstream.
The attribute information encoder 19000 may correspond to the encoder 10002 of
The attribute information encoder 19000 checks a flag indicating whether a Morton code-based index is used (19002). The Morton code-based index may include a Morton code index obtained by converting the coordinate values of the point cloud data into Morton code, or a sequence index obtained by sorting the Morton code indexes in order.
When the attribute information encoder 19000 does not use the Morton code-based index (no), the attribute information encoder 19000 may determine whether an index based on another space search algorithm is used (19004). The other space search algorithm may include, for example, a Hilbert curve, a Peano curve, or a Gray curve as a sorting method for points. In this case, the index based on the other space search algorithm may include an index obtained by transforming the coordinate data of the points according to the above-described sorting methods, or a sequence index assigned based on the sorted order.
When the attribute information encoder 19000 uses the Morton code-based index (yes), the attribute information encoder 19000 may search for neighbors of the current point according to the search conditions (19006). In this case, the neighbor point search may be performed on points that are in a specific range (search range) from the current point among the points that are sorted by a specific sorting method (a Morton curve, a Hilbert curve, a Peano curve, a Gray curve, or the like).
Further, the attribute information encoder 19000 may search for neighbor points through an index calculation process based on a neighbor node table (or look up table) of an N-dimensional space (19008). For example, when the points are sorted in Morton order, points that are at a large index distance from the current point may be searched for as neighbor points by referencing the values contained in the rows and columns of the neighbor node table based on the Morton code index. The neighbor point search based on the neighbor node table according to the embodiments is illustrated in
The attribute information decoder 19010 may perform the decoding operation described above with reference to
The attribute information decoder 19010 may correspond to the decoder 10006 of
The attribute information decoder 19010 check a flag indicating whether a Morton code-based index is used (19012). The Morton code-based index may include a Morton code index obtained by converting the coordinate values of the point cloud data into Morton code, or a sequence index obtained by sorting the Morton code indexes in order.
When the attribute information decoder 19010 does not use the Morton code-based index (no), the attribute information decoder 19010 may determine whether an index based on another space search algorithm is used (19014). The other space search algorithm may include, for example, a Hilbert curve, a Peano curve, or a Gray curve as a sorting method for points. In this case, the index based on the other space search algorithm may include an index obtained by transforming the coordinate data of the points according to the above-described sorting methods, or a sequence index assigned based on the sorted order.
When the attribute information decoder 19010 uses the Morton code-based index (yes), the attribute information decoder 19010 may search for neighbors of the current point according to the search conditions (19016). In this case, the neighbor point search may be performed on points that are in a specific range (search range) from the current point among the points that are sorted by a specific sorting method (a Morton curve, a Hilbert curve, a Peano curve, a Gray curve, or the like).
Further, the attribute information decoder 19010 may search for neighbor points through an index calculation process based on a neighbor node table (or look up table) of an N-dimensional space (19018). For example, when the points are sorted in Morton order, points that are at a large index distance from the current point may be searched for as neighbor points by referencing the values contained in the rows and columns of the neighbor node table based on the Morton code index. The neighbor point search based on the neighbor node table according to the embodiments is illustrated in
The neighbor node table (look up table, LUT) according to embodiments may be generated before a neighbor point search based on a specific sorting method (e.g., Morton order) after the geometry information is compressed by the transmission device according to embodiments (the transmission device of
The transmission device according to the embodiments (e.g., the transmission device of
The encoded point cloud data (or bitstream) according to the embodiments may be generated by the point cloud video encoder 10002 of
Also, the encoded point cloud data (bitstream) according to the embodiments may be decoded by the point cloud video decoder 10006 of
The transmission/reception device according to the embodiments may signal a predictive tree structure to perform a neighbor point search. Parameters (which may be referred to as various terms such as metadata and signaling information) according to embodiments may be generated in a process of the transmission device according to embodiments, and may be transmitted to the reception device according to embodiments so as to be used in reconstructing the point cloud data. For example, the parameters may be generated by the metadata processor (or metadata generator) of the transmission device according to embodiments described below and acquired by the metadata parser of the reception device according to the embodiments.
The abbreviations shown in
Referring to
In addition, when the defined syntax elements are applicable to a plurality of point cloud data streams as well as a point cloud data stream, the related information may be carried in a higher-level parameter set and delivered to the reception device.
Parameters (which may be referred to as various terms such as metadata and signaling information) according to embodiments may be generated in a data processing process of the transmission device (the transmission device of
The point cloud data transmission/reception device according to the embodiments may provide tiles or slices to allow point cloud data to be divided into regions to be processed. The point cloud data transmission/reception device according to the embodiments may provide tiles, or slices, to divide the point cloud data into regions for processing. When the point cloud data is divided into regions, each region may have a different level of importance. Different filters or different filter units may be applied based on the importance, and filtering methods with higher complexity but higher quality results may be applied to important regions.
By allowing different filtering to be applied per region (region divided into tiles or slices) depending on the processing capacity of the reception device, instead of using a complicated filtering method for the entire point cloud, better image quality may be ensured for regions that are important to the user and appropriate latency may be ensured for the system.
When point cloud data is partitioned into tiles, different filters or different filter units may be applied to the respective tiles. When the point cloud data is partitioned into slices, different filters or different filter units may be applied to the respective slices.
The parameters for the neighbor point search according to the embodiments may be applied to each parameter set and signaled.
It may be applied based on the Morton code index or the method indicated by the space_index_search_method. Alternatively, the neighbour_search_function may indicate a calculation method for searching for neighboring points in the neighbor node table based on the index of the current point.
It may be applied based on the Morton code index or the method indicated by the space_index_search_method. Alternatively, the neighbour_search_function may indicate a calculation method for searching for neighboring points in the neighbor node table based on the index of the current point.
When neighbor_context_restriction_flag is equal to 1, NeighbAvailabilityMask is set equal to 13. When neighbour_context_restriction_flag is equal to 0, NeighbAvailabilityMask is set as follows:
The value of log 2_trisoup_node_size shall be equal to or greater than 0. When log 2_trisoup_node_size is equal to 0, the geometry bitstream includes only the octree coding syntax.
It may be applied based on the Morton code index or the method indicated by the space_index_search_method. Alternatively, the neighbour_search_function may indicate a calculation method for searching for neighboring points in the neighbor node table based on the index of the current point.
The value of attr_coding_type shall be equal to 0, 1, or 2 in bitstreams conforming to this version of this Specification. Other values of attr_coding_type are reserved for future use by ISO/JEC. Decoders conforming to this version of this Specification shall ignore reserved values of attr_coding_type (0=Predicting weight lifting, 1=Region Adaptive Hierarchical Transferm(RAHT), 2=Fixed weight lifting).
The value of binaryLevelThresholdRAHT shall be in the range of 0 to xx.
It may be applied based on the Morton code index or the method indicated by the space_index_search_method. Alternatively, the neighbour_search_function may indicate a calculation method for searching for neighboring points in the neighbor node table based on the index of the current point.
The point cloud data transmission method, according to the embodiments includes encoding point cloud data (S2600) and transmitting a bitstream containing the point cloud data (S2610).
The encoding of the point cloud data (S2600) may be performed by the point cloud video encoder 10002 of
The transmitting of the bitstream containing the point cloud data (S2610) may be performed by the transmitter 10003 of
The encoding of the point cloud data (S2600) may include encoding geometry information about the point cloud data, and encoding attribute information about the point cloud data. The encoding of the attribute information about the point cloud data may be performed by the attribute information encoder 19000 of
The encoding of the attribute information may include generating a level of detail (LOD) and sorting the points in order according to a specific sorting method. The attribute information encoder 19000 may generate the LOD and sort the points in each level of the LOD according to the specific sorting method. The specific sorting method may include a sorting method for the points based on various space search algorithms, such as a Morton curve, a Hilbert curve, a Peano curve, or a Gray curve. The operation of generating the LOD may be performed by the LOD generator 40009 of
Further, the encoding of the attribute information includes searching for a neighbor point for the point to predict the attribute information. The attribute information encoder 19000 may predict the attribute information about the current point by searching for a neighbor point having attribute information similar to the attribute information about the current point, and may encode the residual information about the predicted attribute information and the source attribute information and transmit the same to the attribute information decoder 19010.
The searching for the neighbor point by the attribute information encoder 19000 may include searching for points in a specific range from the current point based on the order of the points sorted in a specific method. For example, points whose indexes are within a range of 128 indexes around the current point may be searched for as neighbor points. Related description is given with reference to
Further, the searching for a neighbor point by the attribute information encoder 19000 may include acquiring information about the neighbor point for the current point from a neighbor node table according to embodiments. Here, the neighbor node table includes information about points that are outside the specific range from the current point and have an Euclidean distance from the current point that is within a specific distance (e.g., 1 to 13). The neighbor node table may be an array containing rows and columns.
When searching for a neighbor point, the attribute information encoder 19000 may acquire information about the neighbor point by referencing values contained in a row or column of the neighbor node table based on an index (e.g., a Morton code index) of the current point according to a specific sorting method. Related description is given with reference to
When the attribute information encoder 19000 encodes the attribute information according to the embodiments, the method of sorting the points may be based on various space search algorithms. The method of sorting the points includes sorting based on a Morton curve, a Hilbert curve, a Peano curve, or a Gray curve.
The point cloud data reception method according to the embodiments includes receiving a bitstream containing point cloud data (52700) and decoding the point cloud data (S2710), wherein the decoding of the point cloud data (S2710) includes decoding geometry information about the point cloud data and decoding attribute information about the point cloud data.
The receiving of the bitstream containing the point cloud data (52700) may be performed by the reception device 10004 of
The decoding of the point cloud data (S2710) may be performed by the point cloud video decoder 10006 of
The decoding of the attribute information may include generating a level of detail (LOD) and sorting the points in order according to a specific sorting method. The attribute information decoder 19010 may generate the LOD and sort the points in each level of the LOD according to the specific sorting method. The specific sorting method may include a sorting method for the points based on various space search algorithms, such as a Morton curve, a Hilbert curve, a Peano curve, or a Gray curve. The attribute information decoder 19010 may sort the points according to a specific sorting method based on the signaling information received from the transmission device according to embodiments. The operation of generating the LOD may be performed by the LOD generator 11008 of
Further, the decoding of the attribute information includes searching for a neighbor point for the point to predict the attribute information. The attribute information decoder 19010 may predict the attribute information about the current point by searching for a neighbor point having attribute information similar to the attribute information about the current point, and may restore the attribute information by summing the residual information received from the attribute information encoder 19000 with the predicted attribute information.
The searching for the neighbor point by the attribute information decoder 19010 may include searching for points in a specific range from the current point based on the order of the points sorted in a specific method. For example, points whose indexes are within a range of 128 indexes around the current point may be searched for as neighbor points. Related description is given with reference to
Further, the searching for a neighbor point by the attribute information decoder 19010 may include acquiring information about the neighbor point for the current point from a neighbor node table according to embodiments. Here, the neighbor node table includes information about points that are outside the specific range from the current point and have an Euclidean distance from the current point that is within a specific distance (e.g., 1 to 13). The neighbor node table may be an array containing rows and columns. Information about the neighbor node table may be received from the attribute information encoder 19000.
When searching for a neighbor point, the attribute information decoder 19010 may acquire information about the neighbor point by referencing values contained in a row or column of the neighbor node table based on an index (e.g., a Morton code index) of the current point according to a specific sorting method. Related description is given with reference to
When the attribute information decoder 19010 decodes the attribute information according to the embodiments, the method of sorting the points may be based on various space search algorithms. The method of sorting the points includes sorting based on a Morton curve, a Hilbert curve, a Peano curve, or a Gray curve.
Each element of the attribute information encoder 19000 may correspond to hardware, software, a processor, and/or a combination thereof.
The search for neighbor points according to embodiments is proposed to efficiently compress point cloud data. When points are sorted based on a specific sorting method and only points within a specific range based on the index of the current point are considered as neighbor points, points that are actually positioned at a close distance but are far away in terms of index (jumping points) may not be considered as neighbor points. The transmission/reception device according to embodiments may consider jumping points as neighbor points by acquiring information about the jumping points by referencing the neighbor node table. Searching for closer points as neighbor points may improve the accuracy of prediction of the current point. As the prediction accuracy is improved, the size of the residual information transmitted may decrease. Thereby, the efficiency of data transmission and reception and the processing efficiency may be increased.
Embodiments have been described in terms of the method and/or device, and descriptions of methods and devices may be applied so as to complement each other.
Although the accompanying drawings have been described separately for simplicity, it is possible to design new embodiments by merging the embodiments illustrated in the respective drawings. Designing a recording medium readable by a computer on which programs for executing the above-described embodiments are recorded as needed by those skilled in the art also falls within the scope of the appended claims and their equivalents. The devices and methods according to embodiments may not be limited by the configurations and methods of the embodiments described above. Various modifications can be made to the embodiments by selectively combining all or some of the embodiments. Although preferred embodiments have been described with reference to the drawings, those skilled in the art will appreciate that various modifications and variations may be made in the embodiments without departing from the spirit or scope of the disclosure described in the appended claims. Such modifications are not to be understood individually from the technical idea or perspective of the embodiments.
Various elements of the devices of the embodiments may be implemented by hardware, software, firmware, or a combination thereof. Various elements in the embodiments may be implemented by a single chip, for example, a single hardware circuit. According to embodiments, the components according to the embodiments may be implemented as separate chips, respectively. According to embodiments, at least one or more of the components of the device according to the embodiments may include one or more processors capable of executing one or more programs. The one or more programs may perform any one or more of the operations/methods according to the embodiments or include instructions for performing the same.
Executable instructions for performing the method/operations of the device according to the embodiments may be stored in a non-transitory CRM or other computer program products configured to be executed by one or more processors, or may be stored in a transitory CRM or other computer program products configured to be executed by one or more processors.
In addition, the memory according to the embodiments may be used as a concept covering not only volatile memories (e.g., RAM) but also nonvolatile memories, flash memories, and PROMs. In addition, it may also be implemented in the form of a carrier wave, such as transmission over the Internet. In addition, the processor-readable recording medium may be distributed to computer systems connected over a network such that the processor-readable code may be stored and executed in a distributed fashion.
In this specification, the term “/” and “,” should be interpreted as indicating “and/or.” For instance, the expression “A/B” may mean “A and/or B.” Further, “A, B” may mean “A and/or B.” Further, “A/B/C” may mean “at least one of A, B, and/or C.” Also, “A/B/C” may mean “at least one of A, B, and/or C.” Further, in this specification, the term “or” should be interpreted as indicating “and/or.” For instance, the expression “A or B” may mean 1) only A, 2) only B, or 3) both A and B. In other words, the term “or” used in this document should be interpreted as indicating “additionally or alternatively.”
Terms such as first and second may be used to describe various elements of the embodiments. However, various components according to the embodiments should not be limited by the above terms. These terms are only used to distinguish one element from another. For example, a first user input signal may be referred to as a second user input signal. Similarly, the second user input signal may be referred to as a first user input signal. Use of these terms should be construed as not departing from the scope of the various embodiments. The first user input signal and the second user input signal are both user input signals, but do not mean the same user input signals unless context clearly dictates otherwise.
The terms used to describe the embodiments are used for the purpose of describing specific embodiments, and are not intended to limit the embodiments. As used in the description of the embodiments and in the claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. The expression “and/or” is used to include all possible combinations of terms. The terms such as “includes” or “has” are intended to indicate existence of figures, numbers, steps, elements, and/or components and should be understood as not precluding possibility of existence of additional existence of figures, numbers, steps, elements, and/or components. As used herein, conditional expressions such as “if” and “when” are not limited to an optional case and are intended to be interpreted, when a specific condition is satisfied, to perform the related operation or interpret the related definition according to the specific condition.
Operations according to the embodiments described in this specification may be performed by a transmission/reception device including a memory and/or a processor according to embodiments. The memory may store programs for processing/controlling the operations according to the embodiments, and the processor may control various operations described in this specification. The processor may be referred to as a controller or the like. In embodiments, operations may be performed by firmware, software, and/or a combination thereof. The firmware, software, and/or a combination thereof may be stored in the processor or the memory.
The operations according to the above-described embodiments may be performed by the transmission device and/or the reception device according to the embodiments. The transmission/reception device includes a transmitter/receiver configured to transmit and receive media data, a memory configured to store instructions (program code, algorithms, flowcharts and/or data) for a process according to embodiments, and a processor configured to control operations of the transmission/reception device.
The processor may be referred to as a controller or the like, and may correspond to, for example, hardware, software, and/or a combination thereof. The operations according to the above-described embodiments may be performed by the processor. In addition, the processor may be implemented as an encoder/decoder for the operations of the above-described embodiments.
As described above, related contents have been described in the best mode for carrying out the embodiments.
As described above, the embodiments may be fully or partially applied to the point cloud data transmission/reception device and system. It will be apparent to those skilled in the art that various changes or modifications can be made to the embodiments within the scope of the embodiments. Thus, it is intended that the embodiments cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0060510 | May 2021 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/006637 | 5/10/2022 | WO |
