Information processing device, information processing method, and information processing program

Abstract

An information processing device according to an embodiment includes an acquisition unit, a determination unit, and a decision unit. The acquisition unit acquires point cloud data. The determination unit determines, for each point of the point cloud data, an adjacency relationship relating to the presence or absence of an adjacent point. The decision unit decides a drawing shape of each point on the basis of the adjacency relationship.

Description

Information processing apparatus, information processing method and information processing program

[0001] Embodiments relate to an information processing apparatus, an information processing method, and an information processing program.

[0002] Data of a three-dimensional structure obtained by measuring real space can be represented as a point cloud. When visualizing point cloud data that is a set of points, visualization is performed using a sphere with a radius of any length centered on the coordinate position of each point, or a cube (regular hexahedron) having vertices at points located at any length. For example, in the case of a two-dimensional screen, the data is converted into pixels suitable for two-dimensional screen display, drawn, and displayed.

[0003] As a display style for each point in a point cloud, there is a method in which when a circle or a square is selected in target software, each point of the point cloud is converted into a circle or a square and drawn (see, for example, Non-Patent Document 1).

[0004] QGIS Documentation, "QGIS User Guide 20. Operation of Point Clouds", [online], [retrieved March 18, 2025], Internet <URL: https: / / docs.qgis.org / 3.34 / ja / docs / user_manual / working_with_point_clouds / point_clouds.html>

[0005] However, when points of a point cloud are drawn in the same shape such as a circle or a square, the drawn shape may differ from the structure of real space. For example, a linear object such as an electric wire may be drawn thicker than it is in real space.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an information processing apparatus, an information processing method, and an information processing program capable of drawing a point cloud in a shape closer to the structure of real space.

[0007] The information processing apparatus of an embodiment includes an acquisition unit, a determination unit, and a determination unit. The acquisition unit acquires point cloud data. The determination unit determines, for each point in the point cloud data, an adjacency relationship regarding the presence or absence of an adjacent point. The determination unit determines a drawing shape for each of the points based on the adjacency relationship.

[0008] According to the embodiment, it is possible to provide an information processing device, an information processing method, and an information processing program that can draw point clouds in a shape that is closer to the structure of real space.

[0009] Figure 1 is a block diagram showing the information processing device according to this embodiment. Figure 2 is a flowchart of the initial setup process of the information processing device according to this embodiment. Figure 3 is a diagram showing an example of alignment. Figure 4 is a flowchart of the execution process of the information processing device according to this embodiment. Figure 5 is a conceptual diagram showing an example of the execution process of the information processing device according to this embodiment. Figure 6 is a block diagram showing the hardware configuration of the information processing device according to this embodiment. Figure 7 is a block diagram showing the information processing device according to this embodiment. Figure 8 is a flowchart of the initial setup process of the information processing device according to this embodiment.

[0010] Each embodiment is described below with reference to the drawings. Each embodiment illustrates an apparatus or method for realizing the technical idea of ​​the invention. The drawings are schematic or conceptual. Hereinafter, components having substantially the same function and configuration are denoted by the same reference numeral. The numbers following the letters that constitute the reference numerals are used to distinguish elements that are referred to by reference numerals containing the same letters and have similar configurations. When it is not necessary to distinguish between elements indicated by reference numerals containing the same letters or numbers, these elements are referred to by reference numerals containing only letters or numbers.

[0011] The information processing device 1 according to this embodiment will be described with reference to the block diagram in Figure 1.

[0012] The information processing device 1 according to this embodiment includes an acquisition unit 11, a determination unit 12, a decision unit 13, an assignment unit 14, a drawing unit 15, and a storage unit 16.

[0013] The acquisition unit 11 acquires point cloud data from an input device such as a computer. The point cloud data is, for example, 3D point cloud data obtained by measuring a 3D space, or colored 3D point cloud data in which color information has also been added to the 3D point cloud data.

[0014] The determination unit 12 determines the adjacency relationship for each point in the point cloud data, specifically regarding the presence or absence of adjacent points.

[0015] The determination unit 13 determines the drawing shape of each point in the point cloud data based on the adjacency relationships.

[0016] The assignment unit 14 assigns a shape identifier to each point in the point cloud data, which is an identifier that uniquely determines the drawing shape.

[0017] The drawing unit 15 renders each point, for which a shape identifier has been assigned, using the drawing shape corresponding to the shape identifier, and generates drawing data. For example, it draws three-dimensional volume data.

[0018] The storage unit 16 stores point cloud data, adjacency relationship determination logic, a correspondence table between shape identifiers and drawn shapes, point cloud data with shape identifiers assigned, drawing data, and the like.

[0019] Next, an example of the operation of the information processing device 1 according to this embodiment will be described with reference to the flowchart in Figure 2.

[0020] In step SA1, the acquisition unit 11 acquires point cloud data. For example, points in three-dimensional space are represented as three-dimensional point cloud data of the form (X, Y, Z). If the color information of each point is represented by RGB (Red, Green, Blue) values, it is represented as colored three-dimensional point cloud data in the format (X, Y, Z, R, G, B). Note that the correspondence between real space and the directions of the X, Y, and Z axes is not limited to one type. For example, consider the case where a measurement device such as LiDAR (Light Detection and Ranging) is used, which irradiates laser light and measures real space based on the reflected light from an object. In this case, the measurement device measures real space, and the set of data that stores the coordinate information of points in three-dimensional space where objects exist, but does not store the coordinates of points where objects do not exist, becomes the point cloud data of that real space. Also, the color information is not limited to RGB values, but may also be parameter information such as HSV or HEX.

[0021] In step SA2, the determination unit 12 selects a point of interest from the acquired point cloud data, which is the point to be processed.

[0022] In step SA3, the determination unit 12 determines the adjacency relationship of the point of interest with adjacent points. For example, assuming a three-dimensional space with the point of interest as the center (origin), six directions are defined: the positive and negative directions of the X, Y, and Z axes. The determination unit 12 determines whether or not there are points adjacent to the point of interest in each of the six directions from the point of interest, and the result is defined as the adjacency relationship. The process of determining the adjacency relationship will be described later with reference to Figures 3 and 4.

[0023] In step SA4, the determination unit 13 determines the drawing shape of the point of interest based on its adjacency relationships. For example, the determination unit 13 uses a standard shape for directions where there are adjacent points, and a smaller shape than the standard shape for directions where there are no adjacent points. The process for determining the drawing shape will be described later with reference to Figure 5.

[0024] In step SA5, the assignment unit 14 assigns a shape identifier to the point of interest. For example, if the shape identifier is "S", then for 3D point cloud data, the shape identifier should be assigned to the 3D coordinate information to create point cloud data of the form (X, Y, Z, S). Alternatively, for colored 3D point cloud data, the shape identifier should be assigned to the 3D point cloud data, such as (X, Y, Z, R, G, B, S).

[0025] In step SA6, the storage unit 16 stores point cloud data to which shape identifiers have been assigned.

[0026] In step SA7, the determination unit 12 determines whether all points included in the point cloud data have been processed. If all points have been processed, the process proceeds to step SA8. On the other hand, if there are unprocessed points, the process returns to step SA2, and the same processing from step SA2 to step SA6 is repeated for those unprocessed points.

[0027] In step SA8, the drawing unit 15 places the drawing shape corresponding to the shape identifier in a three-dimensional spatial coordinate system based on each point, performs rendering, and generates drawing data. If color information is included, the drawing unit 15 may generate drawing data with the shape data of the drawing shape colored. The generated drawing data may be output to an external output device, for example, and displayed on a display or the like.

[0028] Note that the process of storing point cloud data to which shape identifiers have been assigned in step SA6 may be omitted. That is, after assigning shape identifiers to points of interest in step SA5, the determination process in step SA7 and the drawing data generation process in step SA8 may be executed consecutively. This allows drawing data to be generated from point cloud data in an online process.

[0029] Next, an example of the adjacency relationship determination process shown in step SA3 will be explained with reference to Figure 3.

[0030] Figure 3 shows the positional relationship between point 301 of interest and other points in six directions: +X, -X, +Y, -Y, +Z, and -Z, with point 301 of interest as the origin of three-dimensional space. Here, a black circle 302 indicates the presence of a point, and a white circle 303 indicates the absence of a point. For example, the determination unit 12 determines that points exist in the +X, -X, +Y, -Y, and -Z directions from point 301 of interest, and therefore adjacent points exist in these directions. On the other hand, since no points exist in the +Z direction, the determination unit 12 can determine that no points exist in the +Z direction.

[0031] Next, another example of the adjacency relationship determination process shown in step SA3 will be explained with reference to Figure 4.

[0032] In Figure 4, a cube centered on point 301 is assumed, and the determination unit 12 determines whether there are a threshold number of points at the center of each face, each vertex, and the midpoint of each edge of the cube. For the sake of explanation, Figure 4 shows the possible positions of the point cloud on the bottom face 401 and the possible positions of the point cloud on the top face 402 opposite the bottom face 401, but in reality, the same determination process should be performed on all six faces.

[0033] First, we focus on the bottom surface 401 in the -Z direction from point 301, as shown in Figure 4. We determine whether a point exists at a total of nine locations: the center of the bottom surface 401, the four vertices of the bottom surface 401, and the four midpoints of each edge of the bottom surface 401. In this case, a point exists at 7 out of the 9 locations, so we can determine that an adjacent point exists in the -Z direction.

[0034] On the other hand, when determining whether or not points exist at the nine locations forming the upper surface 402, points exist at only four of the nine locations. Therefore, it is sufficient to determine that there are no adjacent points in the +Z direction.

[0035] Furthermore, the method for determining adjacent points is not limited to those shown in Figures 3 and 4. For example, adjacent points may be determined by setting the direction of 9 axes instead of 6 axes. Alternatively, adjacent points may be determined based on other shapes such as a regular octahedron, a regular dodecahedron, or a sphere. Alternatively, the area for determining adjacent points may be set to be larger, and it may be determined whether the number of points in that area is equal to or greater than a threshold, or a combination of the above determination processes may be used. In other words, any method that can determine adjacent points by considering the existence of adjacent points with respect to the point of interest may be used.

[0036] Next, the drawing shape of the point of interest in step SA4 will be explained with reference to Figure 5.

[0037] In Figure 5, we assume that the base shape for the drawing is a sphere. However, the base shape is not limited to a sphere; any three-dimensional shape can be used, such as a cube or other polyhedron. Similarly, for two-dimensional shapes, any shape can be used, not limited to a circle, such as a sphere or polygon.

[0038] As shown in Figure 5(a), if all adjacent points exist in each direction to the point of interest 301, the drawn shape 501 is set to a sphere, which is the reference shape.

[0039] FIG. 5(b) shows a case where there is no adjacent point to the point of interest 301 in one direction, and the position of a point with no adjacent point is indicated by an open circle 303. A direction in which no adjacent point exists is configured with a shape smaller than a reference shape. Specifically, in the example of FIG. 5(b), the point is an open circle 303 in the +Z direction, and there is no adjacent point to the point of interest 301 in the +Z direction. Therefore, the determining unit 13 determines, as the drawing shape 502, a three-dimensional shape obtained by combining shapes such that in a hemisphere obtained by cutting a sphere into upper and lower halves, while maintaining the size of the circle of the cut surface, the height of the upper hemisphere, that is, the height in the +Z direction is one half of the radius. That is, in the +Z direction where no adjacent point exists, the height is lower than the height of the reference sphere, and the drawing shape 502 is formed with a smaller shape compared with the drawing shape 501.

[0040] FIG. 5(c) shows that the point is an open circle 303 in the +Z direction and the +X direction, and there is no adjacent point to the point of interest 301 in two directions, the +Z direction and the +X direction. In this case, the determining unit 13 determines, as the drawing shape 503, a shape obtained by combining shapes in which the heights in the +Z direction and the +X direction are each one half of the radius. That is, in the +Z direction and the +X direction where no adjacent point exists, the height is lower than the height of the reference sphere, and the drawing shape 503 is formed with a smaller shape compared with the drawing shape 501 and the drawing shape 502.

[0041] With respect to the point of interest 301, even when there are no adjacent points in 3 directions, 4 directions, and 5 directions, similarly, the drawing shape may be determined by a method of configuring a shape smaller than the reference shape in a direction where no adjacent point exists.

[0042] In addition, when there are no adjacent points at all, the drawing shape may be a sphere having a radius half the size of the reference shape, that is, if the reference shape is a sphere, the radius is one half of the radius of the reference sphere.

[0043] Next, an example of a shape identifier will be described with reference to FIG. 6.

[0044] FIG. 6 shows a correspondence table 60 in which an adjacency relation indicating the presence or absence of adjacent points in each direction based on a point of interest is associated with a shape identifier.

[0045] For example, in the adjacency relationship, a "+" sign is input when there is no adjacent point in the positive direction of each axis, and a "-" sign is input when there is no adjacent point in the negative direction. Herein, the shape identifier is information obtained by summarizing the adjacency relationship. Specifically, when there is no adjacent point only in the +X-axis direction, "+" is input in the X column as the adjacency relationship, and the shape identifier is associated with "1xp" indicating that there is no adjacent point in one direction and the direction is the positive direction of the X-axis.

[0046] Similarly, for example, when there is no adjacent point in three directions: the +X-axis direction, the -X-axis direction, and the -Y direction, the shape identifier is associated with "3xpxmym".

[0047] It should be noted that the shape identifier is not limited to the example shown in FIG. 6, and may be any code or character string that can uniquely identify the combination of directions in which no adjacent point exists.

[0048] Next, a comparative example between the drawing result obtained by the information processing apparatus 1 according to the present embodiment and the conventional method will be described with reference to FIG. 7.

[0049] FIG. 7(a) is a three-dimensional model obtained by rendering, from a point cloud, a line segment 701 existing in real space, such as an electric wire, a fence, or a rope, by a conventional method. In the conventional method, regardless of the presence or absence of adjacent points, points are simply replaced with spheres to form a three-dimensional model. Therefore, herein, the line segment 701 is represented by a three-dimensional model in which four spheres are arranged adjacent to each other.

[0050] On the other hand, FIG. 7(b) shows a drawing result obtained by the information processing apparatus 1 according to the present embodiment.

[0051] For the line segment 701, the presence or absence of adjacent points is taken into consideration, and the point cloud corresponding to the end of the line segment 701 becomes drawing data 702 represented by a shape with nearly vertical ends, and the point cloud corresponding to the central part of the line segment 701 is also represented by a shape with a low vertical dimension. Accordingly, compared with the conventional method, the drawing result obtained by the information processing apparatus 1 according to the present embodiment renders the point cloud in a shape closer to the structure of the line segment 701 in real space.

[0052] Next, an example of the hardware configuration of the information processing apparatus 1 according to the present embodiment will be described with reference to the block diagram shown in FIG. 8.

[0053] As shown in Figure 8, the information processing device 1 includes, for example, a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a display 104, a communication interface 105, and storage 106.

[0054] The CPU 101 is an integrated circuit capable of executing various programs and controls the overall operation of the information processing device 1. The ROM 102 is, for example, a non-volatile semiconductor memory and stores programs and control data for controlling the information processing device 1. The RAM 103 is, for example, a volatile semiconductor memory and is used as a workspace for the CPU 101. The display 104 is, for example, a liquid crystal display or a touch panel display and displays information. The communication interface 105 is, for example, an input / output component for communicating information with the outside world, such as USB, HDMI (registered trademark), or a network interface. The storage 106 is a non-volatile storage device. The storage 106 stores the system software of the information processing device 1. The CPU 101 may also be called a "processor".

[0055] In the above embodiment, the CPU 101 of the information processing device 1 may be other circuits (or processors). For example, the information processing device 1 may include a GPU (Graphics Processing Unit), an NPU (Neural Network Processing Unit), an MPU (Micro Processing Unit), etc., instead of a CPU. Each of the processes described in each embodiment may be implemented by dedicated hardware. The processing of the information processing device 1 may be a mixture of processes executed by software and processes executed by hardware, or it may consist of only one or the other.

[0056] According to the embodiment described above, the determination unit determines the adjacency relationship for each point in the point cloud data, regarding the presence or absence of adjacent points, and the decision unit determines the drawing shape of each point in the point cloud data based on the adjacency relationship. Based on the determined drawing shape, the point cloud data is rendered to generate a two-dimensional model or a three-dimensional model.

[0057] In particular, for directions where no adjacent points exist, the drawing range can be reduced, allowing for smoother rendering of the point cloud data. This enables the point cloud to be rendered in a shape closer to the structure of real space.

[0058] It should be noted that the present invention is not limited to the embodiments described above, and can be modified in various ways during implementation without departing from its essence. Furthermore, each embodiment may be combined as appropriate, and in that case, the combined effects can be obtained. Moreover, the above embodiments include various inventions, and various inventions can be extracted by selecting combinations from the multiple constituent elements disclosed. For example, if the problem can be solved and effects can be obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiment, then the configuration with these deleted constituent elements can be extracted as an invention.

[0059] 1...Information processing device 11...Acquisition unit 12...Determination unit 13...Decision unit 14...Assignment unit 15...Drawing unit 16...Storage unit 60...Correspondence table 101...CPU 102...ROM 103...RAM 104...Display 105...Communication interface 106...Storage 301...Point of interest 302...Black circle 303...White circle 401...Bottom surface 402...Top surface 501, 502, 503...Drawing shape 701...Line segment 702...Drawing data

Claims

1. An information processing device comprising: an acquisition unit for acquiring point cloud data; a determination unit for determining the proximity relationship regarding the presence or absence of adjacent points for each point in the point cloud data; and a determination unit for determining the drawing shape of each point based on the proximity relationship.

2. The information processing apparatus according to claim 1, wherein the determination unit is configured with a reference shape in the direction in which adjacent points exist, and a shape smaller than the reference shape in the direction in which adjacent points do not exist, with the target point to be processed as the drawing shape.

3. An information processing method comprising: an acquisition means acquiring point cloud data; a determination means determining the adjacency relationship for each point in the point cloud data regarding the presence or absence of adjacent points; and a decision means determining the drawing shape of each point based on the adjacency relationship.

4. An information processing program for causing a computer to function as each part of the information processing apparatus described in claim 1.

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